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68g5-105 series mci j4500 coach - North America Transport Air

1. 12 1 Thermal Expansion Valve Refrigerant Liquid Inlet Connection 3 8 ORS Evaporator Heater Coil Assembly Heater Coil Inlet Connection 7 8 OD Evaporator Heat Valve EHV Blower Housing Right Blower Wheel Right Nameplate Evaporator Fan Relay High Speed EFRH Evaporator Fan Relay Low Speed EFRL Elastomeric Motor Mounts 2 Speed Motor Blower Wheel Left Blower Housing Left Service Port Coolant Drain valve Heater Coil Outlet Connection 7 8 OD Capillary Tube and Bulb TXV Refrigerant Suction Outlet Connection 1 ORS Air Bleed Valve Air Filter Channel Figure 1 6 Main Evaporator Assembly 1 6 1 2 4 Main Control Box The main control box See Figure 1 7 includes a main controller microprocessor module expansion output board receptacle quick connectors connectors and fuses F2 and F3 The main controller microprocessor module contains the electronic hardware to measure
2. uOlvuOdvA3 29 124 93509 1009 aw 340 010 zoue 9 1 40 2 34570 IVAH DON 21 Se J ere vo wu XA W3NNIO i Revo o 9 Su3A1uG rave 5 lt X08 1NOHJ EENS EF 1 10 HH X08 r 1NOuJ YNVI 19 T3NNQ1 819 HOIVHOdVA3 HOlVHOdVA3 H1 HOSN3ONOO 1485 AN311VG Lon AN311VG Lon AN311VG r SNIONS C 1NOHJ X08 r 1NOHJ X08 r 1NOHJ r 1NOuJ r 8998 E 31n00N 011 201 YOLVYOdVAS 50 3 312 Figure 5 4 Electrical Schematic Diagram 5 5 Contact vehicle manufacturer for a specific diagram A Air Conditioning Refrigerant Cycle 1 12 Air Filter 3 6 4 14 Checking For Noncondensible
3. ICH O UU UD UD UD um PUMP END VIEW 1 o e ONS NE Bech J iv yer D O 11 CURBSIDE VIEW 12 TOP VIEW 1 2 3 4 5 6 7 8 9 Suction Pressure Transducer Bracket Belt Guard Weatherpack Clutch Coil Connector Electric Solenoid Unloader Discharge Valve Connection Size 16 ORS Discharge Service Valve Discharge Valve Charging Port O Ring Oil Drain Plug Solenoid Unloader Electric Connectors High Pressure Switch Discharge Pressure Transducer Capscrew Lockwasher Special Washer Lock Nut Key Suction Valve Charging Port Suction Service Valve Clutch Assembly Oil Fill Plug Oil Level Sightglass Suction Valve Connection Size 24 ORS O Ring Figure 1 3 Compressor Assembly 1 3 T 312 1 2 2 Compressor Assembly The compressor assembly See Figure 1 3 includes the refrigerant compressor clutch assembly suction and discharge service valves high pressure switch suction and discharge pressure transducers suction and discharge servicing charging ports and electric solenoid unloaders The compressor raises the pressure and temperature of the r
4. 24DC 6 PARCEL RACK ROAD SIDE PARCEL RACK CURB SIDE GRD STUD GRD STUD x THERMOSTAT NOTE In 2003 early production units were retrofitted with diodes If servicing a unit that is not wired as shown above the unit should be retrofitted Contact Carrier Service Engineering INDICATES THESE COMPONENTS ARE See Figure 5 1 for legend and symbols SUPPLIED BY MOTOR COACH INDUSTRIES MCI Figure 5 2 Electrical Schematic Diagram Sheet 1 of 2 Based On Drawing 62 10907 5 3 T 312 ION 5418415 0 1 HOVOD YOLOW A8 04114405 SINJNOdWOO ASSHL SALVOTONI 3015 8809 30uvd ud oo Vyd 301S 0808 OWE 1304 d Hd ud ave 3 30 lt 03345 0 30 2 30 8 30 X08 10 1 02 H3A 30 7 420 ualvad xnvxx HOLVHOdYAZ X08 Y3SNIONOI 1v 1v ASHd 459 270 2u39 Ed 939 Y Z4 935 A 9 lt 1d
5. 4 14 4 26 Motor Hemioval i a spore rh EAS epe Pee EET ER 4 14 4 26 2 Removal of Parcel Rack Evaporator Coil 4 14 ELECTRICAL SCHEMATIC DIAGRAMS 5 1 bi INTRODUCTION one Robe yea lg Gerd data 5 1 LIST OF ILLUSTRATIONS Figure Page 1 1 Coach Cutaway View 1 1 1 2 Condenser Assembly 1 2 1 3 Compressor Assembly 1 3 1 4 Driver Evaporator Assembly 1 5 1 5 Rack Evaporator i EL NES ale EEE enc A 1 5 1 6 Main Evaporator Assembly 2 cee ais Eee eO E PER Sa PERSE 1 6 127 Main Control Box rcg hone alge aot WO OR 1 7 1 8 System Operating Controls upper left hand switch panel 1 8 1 9 Parcel Rack On Off ob Rete e ee pale Pale e kurqa 1 8 1 10 Driver A G oem etek a Re EEN 1 9 1 11 Heating System Flow Diagram 1 11 iii T 312 LIST OF ILLUSTRATIONS Continued Figure Page 1 12 Air Conditioning Refrigerant Flow Diagram 1 13 Electronic Automatic Control D
6. ate Qi ety 2 3 2 1 7 Diagnostics Parameters 2 3 2 1 8 StOpplhg Gael ae Gh ae Mb eM E 2 3 2 2 J PRE TRIP INSPEGTIQN Eq M RERUM Gea 2 3 2 3 SYSTEM DESCRIPTION L ul aa MEER MH eet 2 3 2 3 1 Pull Up and Pull Down Modes 2 3 2 3 2 Bypass Heat valve Control 2 5 2 3 3 Auxiliary Heater Control 2 5 2 8 4 Humidity Control 2 5 2 8 5 Compressor Unloader 2 5 2 3 6 Passenger Area Evaporator Fan Speed Selection 2 5 2 3 7 Driver s Area Evaporator Fan Speed Selection 2 5 2 3 8 Condenser Fan Speed Control 2 5 2 3 9 Staging esce DA Lee oa se 2 6 2 3 10 Compressor Clutch Control 2 6 2 9 11 RAM Air Control sansun cepa 2 6 2 312 STAND EE lest ig Gale ig De Sige xe vbi aed 2 6 2 3 13 Input Processing x pner gb at ee td De del 2 6 2 89 14 Self E ire oin ganaq aaa k ae huq eq aaa a Aa dae bre bbs ac nte ee
7. LSV PRESSURE SENSOR 2 PRESSURE SWITCH NC TEMPERATURE SENSOR RESISTOR D MU ux 1 AUTO RESET BREAKER THERMAL OVERLOAD NC X X Z2 X CU OU IL ms D fn CO CO CQ CD THERMAL OVERLOAD NO SUCTION PRESSURE TRANSDUCER TEMPERATURE SENSOR CURB TEMPERATURE SENSOR ROAD UNLOADER SOLENOID VALVE 1 UNLOADER SOLENOID VALVE 2 RELAY COIL SOLENOID COIL MODULE INDICATES THESE COMPONENTS ARE SUPPLIED BY MOTOR COACH INDUSTRIES MCI CONNECTOR SET SPDT SWITCH NDICATES LED NDICATES WIRE CONNECTION TE INSIDE MODULE WIRES ARE FACTORY WIRED DULE TO MODULE WIRE CONNECTIONS ARE FIELD WIRED A THRU K L THRU f Sy COACH INTERFACE PACKARD CONNECTOR CONNECTOR Figure 5 1 Electrical Schematic Diagram Legend and Symbols Based On Drawing No 62 10907 T 312 5 2 CONDENSER MAIN EVAPORATOR 24VDC o4 bo EFRH 2400 6 gt 55 o4 Fo 70A 1 2 Sei L A E C 24VDc 67 EN E E ceo DRIVER EVAPORATOR DRIVER CONTROL BOX
8. TXV BULB ARR At RAAT RANE DRIVER EVAPORATOR SERVICE PORT ASSEMBLY z TXV BULB EI J PASSENGER EVAPORATOR ASSEMBLY PARCEL EVAPORATOR PARCEL RACK ASSEMBLY LIQUID LINE MAIN LIQUID LINE SOLENOID VALVE SOLENOID VALVE FILTER DRIER CONDENSER lt ASSEMBLY SERVICE SIGHT A PORT GLASS CONDENSER gt SUBCOOLER FUSE q PARCEL EVAPORATOR PLUG ASSEMBLY SERVICE DISCHARGE LINE PORT SERVICE VALVE DISCHARGE CHECK VALVE 55 SUCTION LINE DISCHARGE LINE SERVICE PORT Figure 4 4 Refrigerant Service Connections 4 5 T 312 47 ADDING REFRIGERANT TO SYSTEM 4 7 1 Checking Refrigerant Charge a Connect an accurate high pressure gauge to the discharge service port at the compressor See Figure 4 4 b The condenser coil should be clean and free of any debris Coach engine operating at high idle 800 1000RPM The compressor should be fully loaded six cylinder operation Unit must be operating in the cool mode until the discharge pressure has stabilized 3 to 5 minutes and the interior temperature is between 70 and 80 F 21 1 and 26 7 C f Di
9. BOLS END SYMBOL IPTIO A WIRE GROUND AT T TEMPERATURE SENSOR GROUND STUD CONNECTION xxBPHY BY PASS HEAT VALVE C A CONDENSER CONNECTOR BUS INTERFACE POWER STUD xxCB CIRCUIT BREAKER xxCB CIRCUIT BREAKER A CONNECTOR PIN CFRI CONDENSER FAN RELAY 1 CFR2 CONDENSER FAN RELAY 2 A NORMALLY OPEN CONTACT CONDENSER FAN MOTOR 1 CM2 CONDENSER FAN MOTOR 2 A NORMALLY CLOSED CONTACT CL LUTCH RELAY CSRI ONDENSER SPEED RELAY A DIODE DC F VER CONTROL CONNECTOR BUS INTERFACE DC VER CONTROL BOX CIRCUIT BREAKER 1 SPLICE CONNECTION DC VER CONTROL BOX CIRCUIT BREAKER 2 DC VER CONTROL BOX FAN RELAY LOW SPEED DE A VER EVAPORATOR CONNECTOR BUS INTERFACE DEMI VER EVAPORATOR MOTOR 1 DEM2 VER EVAPORATOR MOTOR 2 VER HEAT VALVE VER LIQUID LINE CONNECTOR BUS INTERFACE VER LIQUID SOLENOID VALVE PT SCHARGE PRESSURE TRANSDUCER R A VER RAM AIR CONNECTOR BUS INTERFACE A EVAPORATOR CONNECTOR BUS INTERFACE RH EVAPORATOR FAN RELAY HIGH SPEED RL EVAPORATOR FAN RELAY LOW SPEED EVAPORATOR HEAT VALVE SV EVAPORATOR LIQUID SOLENOID VALVE EVAPORATOR MOTOR FUSE CUSTOMER SUPPLIED HIGH PRESSURE SWITCH HUMIDITY SENSOR PARCEL RACK CONNECTOR BUS INTERFACE PARCEL RACK MOTOR CURB SIDE ROAD SIDE PARCEL RACK A C SWITCH PARCEL RACK SOLENOID VALVE RAM AIR SOLENOID DRIVER RAM AIR SOLENOID PASSENGER SUPPLY AIR THERMOSTAT CROAD SIDE ONLY T 2 FUSE MOTOR
10. 4 2 4 4 1 System Pumpdown 4 2 4 4 2 Removing the Refrigerant Charge 4 3 4 4 8 Refrigerant Removal From An Inoperative Compressor 4 3 444 Pump Down An Operable Compressor For Repair 4 3 45 REFRIGERANT LEAK CHECK 4 4 4 6 EVACUATION AND DEHYDRATION 4 4 4 6 1 General eee b ede Waa e e ERR ea d ai 4 4 4 6 2 Pr paration peknpPienzekEr leet i ehe dee ad 4 4 4 6 3 Procedure for Evacuation and Dehydrating System 4 4 47 ADDING REFRIGERANT TO SYSTEM 4 6 4 7 1 Checking Refrigerant Charge 4 6 4 7 2 Checking Refrigerant Charge Alternate Method 4 6 4 7 3 Adding F ull Charge EDEN Qa TE 4 6 4 7 4 Adding Partial Charge 4 6 4 8 CHECKING FOR NONCONDENSIBLES 4 6 4 9 CHECKING AND REPLACING HIGH PRESSURE CUTOUT SWITCH 4 7 4 9 1 Replacing High Pressure Switch 4 7 4 9
11. BIY SH3A TUO 010 3705 5 180 1V34 5 H3ON3SSVd HIN WWE 8 xnv Y 2 HOSN3UNOO 2 HOSN3ONDO 03395 YOSNSONOD 1V3H H1 NIVN 1V34 NIVN NI VA NIVN NOT NI VA OVO MAD 1 HOSN3ONOO 1 H30vONn 2 H3ovo Nn 1 HOSN3ONO9 H21019 v2 SdH amu ren 24222 04 24 IIS EEUU SSN mY EE EY icu S OHIO d eeng 01 5 QvOTH3AO 1H9 H NIVN erer 1 337 NIVN GHI H1 NIVN HT NIVA i C ONO 49N0 NANI HH NI VW HOLIAS 3unssaud HOIH 3 OND 1N3IONV 558 ono 5 XL Avast WH3HL 1N31 NV OND NHnI3H AdddnS S H3A 180 7000 01 WH3HL ATdANS 5 70009701V Mai S N3AINO BOSN3S ALIQINDH NOSN3S ALIQ NDH BOSN3S ALIQIADH OND 3unss3Hd BSNBS 3osvHOSIO 43855364 3OHVHOS 10 ON9 553 NO 1216 3SN3S NO LONS s38n55384 ND LINS HOLIMS 9 V 5 1 2 B3 TIOMINOD IVAH 5 pe zL d
12. d Start the unit and run in cooling until 10 hg 25 4 cm hg of vacuum is reached Shut the system down and tag out system power source e Frontseat the compressor discharge service valve and wait 5 minutes to verify vacuum is maintained f Remove the crankcase oil fill plug on the side of the crankcase Replace the crankcase oil fill plug with a Carrier Service Parts no 889 fitting This fitting has a 1 4 inch flare access port with a shrader valve Using refrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge set CAUTION Care Must Be Taken To Ensure That The Manifold Common Connection Remains Immersed In Oil At All Times Or Air And Moisture Will Be Drawn Into The System 2 i Connect a refrigerant hose with a shrader depressor to the fitting described in step g above put the other end of the hose in a fresh oil container j Evacuate the compressor and observe the oil level in the compressor crankcase When the desired oil level is reached disconnect the hose from the fitting Reinstall the crankcase oil fill plug Usingrefrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge set Evacuate system to 500 microns Close off pump valve isolate vacuum gauge and stop pump Wait 5 minutes to verify that vacuum holds m Once vacuum is maintained backseat compressor Service valves and disco
13. ed to a maximum of thirty minutes and can be put in pullup pulldown speed only once When the control ler switches out of pullup pulldown speed pullup pulldown speed is prevented again by the controller unless the controller is shut off and restarted The display cannot override the fan speed to pullup pull down The minimum run time in pullup or pulldown for the main evaporator fans is three minutes for automatic control a Capacity State Selection The main controller automatically compares system temperature with the controller set point and changes system operating modes at certain temperature deviations Figure 2 4 shows various changes in operating modes and controller actions at various temperature deviations from controller set point Upon rising temperature mode changes occur at values in Figure 2 4 above controller set points On a falling temperature mode changes occur when temperatures are equal to those given in Figure 2 4 The system will operate in these modes unless pressure overrides the controller settings If the controller detects that the temperature setting is not being reached during a period of time it will slowly adjust the temperature at which these modes are entered this will allow the system to always attempt to reach the controller temperature setting T 312 A EVAPORATOR RETURN AIR TEMP ABOVE SET POINT COOLING MODE HIGH SPEED MAIN EVAP FAN COMPR FULLY LOADED 6 CYL 8 5 F 475 C COOL
14. sired press the corresponding button refer to Figure 2 1 to illuminate the indicator light and manu ally place the system in that mode of operation 4 If low or high speed evaporator fan speed is desired press the FAN SPEED button to illuminate the indi cator light and bring speed to the desired level 5 To open or close the fresh air damper press the FRESH AIR button 6 To read interior or exterior temperature press the TEMPERATURE button to illuminate the indicator light and bring the display to the desired temperature reading After a short delay the display will return to the default set point or return air temperature read ing 7 Setpoint may be changed by pressing the UP or DOWN arrow button The UP button will increase the setpoint temperature and the DOWN button will de crease the setpoint temperature 2 1 44 Activating Defrost Windshield defrost is initiated and controlled with the Defrost switch and the Heat switch Figure 2 1 Moving the switches to the high setting on both will deliver the highest volume of warm air on the windshield Correspondingly moving either or both of the two switches to the low setting will decrease the volume of air and the temperature of air delivered across the windshield 2 1 5 Active Alarm During normal operation the controller monitors system operating parameters for out of tolerance conditions The display gets the controller alarm queue information every 30 seconds
15. 2 Checking High Pressure Switch 4 7 4 10 FIETER DRIER uei Tert ere Pelei E tere aTh 4 7 4 10 1 To Check Filter 4 7 4 10 2 To Replace Filter Drier EU ex nadine betas 4 7 4 11 THERMOSTATIC EXPANSION VALVE 4 7 4 11 1 Replacing the Expansion 4 7 4 11 2 Check Measure 4 8 T 312 ii TABLE OF CONTENTS Continued Section Page 4 12 MODEL 058 COMPRESSOR MAINTENANCE 4 8 4 12 1 Removing the Compressor 4 8 4 12 2 Re installing the Compressor 4 9 4 12 3 Compressor Unloaders 4 9 4 12 4 Compressor Oil 4 10 4 12 5 Adding Oil with Compressor in System 4 10 4 12 6 Adding Oil to Service Replacement Compressor 4 10 4 12 7 Removing Oil from the Compressor 4 10 4 13 TEMPERATURE SENSOR 4
16. Alarms will be shown as an alarm code If an alarm is activated and the display is reading temperature the display will show the temperature and the alarm code alternately in 1 second intervals 2 1 6 Diagnostics Check for Alarms If an alarm condition exists diagnostics can be manually initiated to isolate system fault s by simultaneously pressing the Up and Down Selection keys continuously for five seconds Diagnostics should be accessed only when the coach is not moving When entering the diagnostic mode all LEDs for the key pad will be turned off All keys except the On Off Up increase Selection and Auto keys will stop functioning To scroll through the diagnostic information press the UP key Pressing the O I key at any time will exit this mode To clear the alarm message scroll thru the alarms until appears then press the Auto Key for 5 seconds or until disappears Refer to section for description of diagnostics Refer to Table 3 3 for definition of alarm messages 2 1 7 Diagnostics Parameters To access the system parameters press the Up and Down Selection keys continuously for five seconds The display will now be in the Diagnostics mode and may be displaying alarms Scroll thru the alarms if present until appears With displayed on the read out press the Up Selection key The first parameter code will be displayed To scroll thru the parameters press the Up Selection key When showing paramet
17. Fitting 0 5 16 Acme Refrigeration and or Evacuation Hose SAE J2196 R 134a Hose Fitting w O ring M14 x 1 5 High Side Field Service Coupler Low Side Field Service Coupler Figure 4 2 Manifold Gauge Set R 134a 4 3 1 Installing R 134a Manifold Gauge Set An R 134a manifold gauge hose set with self sealing hoses is required for service of models covered within this manual The manifold gauge hose set is available from Carrier Transicold CTD P N 07 00294 00 which includes items 1 through 6 see Figure 4 2 To perform service using the manifold gauge hose set do the following a Preparing Manifold Gauge Hose Set For Use 1 If the manifold gauge hose set is new or was exposed to the atmosphere it will need to be evacuated to remove contaminants and air as follows 2 Back seat turn counterclockwise both field service couplers See Figure 4 2 items 5 and 6 and midseat both hand valves 3 Connect the yellow hose to a vacuum pump and an R 134a cylinder 4 Evacuate to 10 inches 0 69 BAR of vacuum and then charge with R 134a to a slightly positive pressure of 1 0 psig 0 07 BAR T 312 5 Front seat both manifold gauge set hand valves and disconnect from cylinder The gauge set is now ready for use b Connecting Manifold Gauge Hose Set To connect the manifold gauge hose set for reading pressures do the following 1 Remove service valve stem cap and check to make sure it is backseated Remove a
18. Manual Form No 62 02756 T 312 3 6 SECTION 4 SERVICE WARNING BE SURE TO OBSERVE WARNINGS LISTED IN THE SAFETY SUMMARY IN THE FRONT OF THIS MANUAL BEFORE PERFORMING MAINTENANCE ON THE HVAC SYSTEM NOTE Following completion of all maintenance or service activities the alarm queue should be cleared of any original alarms and any alarms generated during service Refer to paragraph 2 1 6 4 1 MAINTENANCE SCHEDULE a END Maintenance X Pre trip Inspection after starting X Check tension and condition of V belt b Weekly Inspection HEUS OPERATION Perform daily inspection X Check refrigerant hoses and compressor shaft seal for leaks Feel filter drier for excessive temperature drop across drier c Monthly Inspection and Maintenance Perform weekly inspection and maintenance Clean evaporator drain pans and hoses Check wire harnesses for chafing and loose terminals Check fan motor bearings Check compressor mounting bolts for tightness Check fan motor brushes None Replace Tighten None None 4 19 4 23 4 2 SUCTION AND DISCHARGE SERVICE VALVES The suction and discharge service valves See Figure 4 1 used on the compressor are equipped with mating flanges for connection to flanges on the compressor These valves are provided with a double seat and a gauge connection which allows servicing of the compressor and refrigerant lines Turning the valve stem counterclockwise all the way out will backseat
19. Meee dia daa RE 1 7 1 2 5 System Operating Controls And Components 1 8 1 2 6 Other Carrier Supplied 1 9 13 REFRIGERATION SYSTEM COMPONENT SPECIFICATIONS 1 9 14 ELECTRICAL SPECIFICATIONS WOUNDFIELD MOTORS 1 9 15 ELECTRICAL SPECIFICATIONS MAIN CONTROLLER INPUT SENSORS AND TRANS DUCE RD e Rm dea 1 9 1 6 SAFET DEVIGE S f ex eb URS NO PE 1 10 1 7 HEATING ENGINE COOLANT FLOW CYCLE 1 11 18 AIR CONDITIONING REFRIGERANT CYCLE 1 12 1 9 ELECTRONIC AUTOMATIC CONTROL DATA FLOW 1 14 OPERATION 4 2 5 5 te tees hte er 2 1 2 1 STARTING STOPPING AND OPERATING INSTRUCTIONS 2 1 2 1 1 Operating Controls 2 1 2 1 2 HVAC Power to Controller 2 2 2 1 3 Starting eek tacts hd ie bind NEE bead eae 2 2 2 1 4 Activating Defrost 2 3 2 1 5 Setting RAM Fresh a ERU EI 2 3 2 1 6 ACTIVE Alarm eae Ore
20. Resistance In Ohms 285 233 17 8 67 SE 10 0 15 6 23 25 80 267 90 322 375 453 48 9 4 13 TEMPERATURE SENSOR CHECKOUT a accurate ohmmeter must be used to check resistance values shown in Table 4 3 20 10 20 30 32 40 50 70 77 o C 289 293 178 22 NE Ke 0 100 156 211 2 267 322 378 433 489 b Due to variations and inaccuracies in ohmmeters thermometers or other test equipment a reading within two percent of the chart value would be considered good If a sensor is bad the resistance value would usually be much higher or lower than the value given in the Table 4 3 NOTE This system is equipped with three temperature sensors two located in the return air ducts inside the coach the third sensor is located in the condenser section The two inside sensors are wired in parallel and together send an averaged signal to the controller If one of these sensors fails the control function will continue with the remaining sensor The sensor located in the condenser section reads outdoor temperature 4 14 HUMIDITY SENSOR CHECKOUT a Use a sling psychrometer or similar device to check relative humidity inside the coach NOTE System can be shut down but 5 vdc power must be applied to the humidity sensor to enable checking b Measure voltage across the sensor and compare to values in Table 4 4 for the measured
21. The refrigerant cycle will remain off ma Discharge Liquid Eessen Suction DRIVER SOLENOID VALVE gt TXV BULB DRIVER EVAPORATOR ASSEMBLY SERVICE PORT 5 TXV BULB MAIN EVAPORATOR ASSEMBLY SERVICE CONDENSER ASSEMBLY MAIN LIQUID LINE SOLENOID VALVE PARCEL RACK ASSEMBLY PORT PARCEL EVAPORATOR LIQUID LINE SOLENOID VALVE CONDENSER SUBCOOLER FILTER DRIER lt SERVICE PORT FUSIBLE ASSEMBLY PLUG LIQUID LINE KING DISCHARGE LINE SERVICE VALVE SERVICE VALVE DISCHARGE LINE SERVICE PORT DISCHARGE CHECK VALVE COMPRESSOR Figure 1 12 Air Conditioning Refrigerant Flow Diagram PARCEL EVAPORATOR T SERVICE PORT SUCTION LINE T 312 1 9 ELECTRONIC AUTOMATIC CONTROL DATA FLOW The system is supplied with 12 and 24 power from the coach power supply The main controller receives input from pressure transducers temperature sensors condenser and evaporator fan motor overloads high pressure switch fuses It then processes these inputs to
22. cooling and the compressor will shut down The heating capacity can then be varied by adjusting the time the heat valve is open The time is automatically calculated by the controller and is based on a 20 second period d Driver Area Control The Driver s A C switch on the left side console is turned on when cooling is desired in the driver area The driver area conditions are controlled by manually adjusting the Defrost and Heat slide switches on the dash board These controls operate in conjunction with the main coach controller Temperature control is ac complished by regulating the flow of engine coolant through the heating coil in the driver evaporator with the Heat slide switch by controlling anormally open electric solenoid valve The volume of air flow directed about the driver area is controlled with the Defrost slide switch by the speed of the drivers evaporator fan motors The heating coil reheats the precooled air to maintain the desired temperature at the set point During heat ing the driver area liquid solenoid valve is closed and the heating valve is opened and closed for a percentage of the heat valve period e Passenger Area Control The passenger area temperature is controlled by maintaining the return air temperature as measured by the return air sensors located at the rear of the coach in the return air ducts The return air Sensors are averaged together to provide input for the controller If cooling is
23. fan motors as they start immediately Staging for the evaporator and condenser fan motors are given in the Table 2 2 Table 2 2 Main area Staging Controller Action Time 0 Main Evaporator Fan Low T T Main Evaporator Fan High Condenser Fan 1 Low Time 3 1 Condenser Fan 2 Low Both Condenser Fans High 2 3 10 Compressor Clutch Control A belt driven electric clutch is employed to transmit en gine power to the air conditioning compressor De ener gizing the clutch electric coil disengages the clutch and removes power from the compressor The clutch will be engaged whenever any area is calling for cooling The clutch will be disengaged when the system is off when all areas are in heating or during high and low pressure conditions The clutch coil is controlled by the main con troller The clutch coil is prevented from engagement when the ambient temperature is below 32 F 0 C The clutch coil will be de energized if the discharge pressure rises to 350 psig 2 4 mPa the setting of the compressor mounted high pressure switch The clutch coil will energize when the discharge pressure falls to 240 psig 1 7 mPa The clutch coil will be de energized if the suction press ure decreases below 6 psig 41 kPa 2 3 11 RAM Air Control The RAM air control regulates admission of outside air into the system T 312 a Display Override The RAM air can be automatically controlled or set to open or c
24. inputs and process the outputs to automatically control 5 the air conditioning and heating system to maintain temperatures inside the coach The microprocessor section has a built in memory facility for checking proper operation this includes checks of the program memory data memory and analog It has a self test feature which is executed when the system is first powered up The expansion board drives six discrete outputs in addition to the standard outputs from the controller Q30218NY81 4 6 7 8 9 6666 6666 9696 j 0 raue Nes SS Du Connector MA Connector MB Not Used Fuse F2 Not Used Fuse F3 Not Used Quick Connector QC1 Connector KA Connector KB Connector MA Quick Connector QC2 Connector MB Rela
25. mode HVAC system operation will automatically stop if the HPS switch contacts open due to an unsafe operating condition Opening HPS contacts de energizes through the main controller the A C compressor clutch and condenser fan relays shutting down the system b Fuses Fuses F2 and F3 Fuse F2 internal to the controller protects the controller 12 vdc supply circuit from excessive current draw Fuse F3 protects the controller 24 vdc output circuit from excessive current draw c Thermal Switches Condenser Motor Overloads CMOL1 and CMOL2 Each condenser fan motor is equipped with an internal thermal protector switch condenser motor overloads CMOL1 and CMOL2 If excessive motor temperature exists the CMOL switch will open to de energize the corresponding condenser fan relay CFR1 or CFR2 this will stop the affected condenser motor Table 1 3 Safety Devices For Carrier Supplied Equipment Unsafe Condition Safety Device High compressor discharge High Pressure Switch HPS pressure Excessive current draw by the Fuse F2 controller 12 vdc supply circuit Excessive current draw by the Fuse F3 controller 24 vdc output circuit Refer to 1 3 d Opens at 5 amps Opens at 10 amps T 312 1 7 HEATING ENGINE COOLANT FLOW CYCLE Heating circuit components furnished by Carrier Transicold include heater cores and evaporator heat valves EHV for the driver and main evaporator assemblies and a coolant bypass heat val
26. of both condenser fan motors CM1 and CM2 The main evaporator liquid line solenoid valve and the parcel rack liquid line solenoid valve when so equipped closes when the system is shut down to prevent refrigerant migration and to isolate the filter drier for servicing when the compressor is shut down The king valves enable servicing of the condenser assembly The ambient temperature sensor measures ambient temperature and sends an electrical signal to the main controller 20 19 18 Condenser Coil Assembly Fusible Plug Liquid Line Outlet Fitting Parcel Rack Liquid Line Outlet Fitting Main Model Serial No Nameplate Fan Guard Filter Drier Venturi Ring Condenser Fan Motor CM1 Fan Blade Condenser Fan Motor CM2 Outside Temperature Sensor SON OO Control Box Contains Condenser Fan Relay No 1 CFR1 Condenser Fan Relay No 2 CFR2 and Condenser Speed Relay No 1 CSR1 Moisture amp Liquid Indicator Control Box Positive Stud Control Box Positive Stud Control Box Negative Stud Liquid Line King Valve Discharge Shutoff King Valve Refrigerant Inlet Fitting Figure 1 2 Condenser Assembly T 312
27. other than alarm If the compressor is energized and the first condenser fan overload opens the microprocessor will ener gize the second condenser fan in or der to detect the first overload con dition If after energizing the second con denser fan the second condenser fan overload opens the compressor clutch will de energize for the mini mum off time since neither con denser fan is operating A25 Table 3 3 Driver Display Panel Alarm Message Definition Continued OT TITLE CAUSE REMEDY MICROPROCESSOR RESPONSE Condenser Fan Overload continued Out of Range Low Voltage Load Shed Condenser fan over loads If the system is con trolling within 9 F 5 C of setpoint for a period of 15 minutes and then fails to con trol within 18 F 10 C for any reason this alarm will be acti vated Low coach voltage Coach 12 vdc battery supply voltage dropped below 12 6 vdc for 30 seconds Refer to section 3 3 3 and or 3 3 4 Check discharge pressure transducer voltage wiring or cause of high dis charge pressure Re fer to section 4 15 and Table 4 5 and or sec tion 3 3 3 Refer to section 3 3 1 3 3 2 and or 3 3 8 de pending on heating cooling requirements Check repair alterna tor or coach power supply 3 3 If after energizing the second con denser fan the second condenser fan overload does not open the micro processor will keep the first over load alarm activa
28. panel near the transmission gear selector This switch will activate the system to provide cooling for the driver in the event that cooling is not called for by the Carrier Transicold microprocessor Figure 1 10 Driver A C 1 2 6 Other Carrier Supplied Items Other Carrier supplied items include curbside and roadside return air temperature sensors two coolant control valves and a check valve The temperature sensors provide input to the controller on temperature conditions in the coach The bypass heat coolant control valve provides a path for coolant flow when all evaporator heat valves are closed The other coolant control valve is the heat valve that controls the flow of coolant to the driver heater coil The check valve is installed in the compressor refrigerant discharge line and allows refrigerant flow in only one direction to prevent liquid return to the compressor when the compressor is shut down 1 3 REFRIGERATION SYSTEM COMPONENT SPECIFICATIONS a Refrigerant Charge R 134a 17 5 lb 8 kg b Compressor Model 05G No of Cylinder 6 Weight Dry 145 66 kg including clutch Oil Charge New Compressor 5 8 pints 2 7 liters Replacement Compressor 5 5 pints 2 6 liters Oil Level Level in sight glass between bottom of glass and middle of glass on compressor crankcase curbside Approved Compressor Oils R 134a Castrol Icematic SW68C Mobil EAL Arctic 68 Emkarate RL68H c Thermostatic Expansio
29. the engine is off When placing the switch in the ON position the switch activates the auxiliary heater for a timed period of 90 minutes Placing the switch in the OFF position or starting the coach engine will de activate the auxiliary heater 2 3 4 Humidity Control Humidity control reheat mode is activated when the humidity is greater than fifty percent and the passenger zone temperature is less than 5 F 320 above set point When these conditions are met the compressor will be fully loaded 6 cylinders and at the same time the heat valve s will cycle open to maintain temperature Once humidity control is activated it will remain activated until the humidity is less than 45 percent or the return air temperature drops 2 F 1 C below set point 2 3 5 Compressor Unloader Control The unloader outputs control the capacity of the compressor by energizing or de energizing unloader solenoid valves Energizing valve solenoid de activates a pair of compressor cylinders The 05G compressor has six cylinders Four cylinders are equipped with two sets of unloader valves UV1 and UV2 each controlling two cylinders this allows the compressor to be operated with two four or six cylinders When the compressor is off the unloader solenoids are de energized immediately Whenever the compressor is changed from off to on the unloaders are forced energized for fifteen seconds After fifteen seconds one unloader solenoid may be de energi
30. with hand valves near vacuum pump to the suction and discharge service valves Fully backseat open counterclockwise both suction and discharge service valves Remove vacuum pump lines and install manifold gauges Start unit and check refrigerant level Refer to paragraph 4 7 1 Check compressor oil level Refer to paragraph 4 12 4 Add or remove oil if necessary Check compressor unloader operation 4 12 3 Compressor Unloaders Although the electric unloaders are non adjustable they will require some periodic maintenance Service kits are available for repair of the electric unloaders solenoid and stem assemblies To check the unloaders proceed as follows a Ensure that the compressor is fully loaded Heat the interior of the coach if necessary Electric Unloader Valve Suction Service Valve Charging Port Suction Service Valve Clutch Oil Fill Plug Bottom Plate Oil Drain Plug Oil Level Sight Glass Oil Pump 10 O Ring Discharge Service Valve Service Port Figure 4 9 Model O5G Compressor b Connect manifold guages to the compressor Slowly frontseat the suction valve until 26 psig shows on the suction guage The first unloader should energize check for magnetism at the unloader coil increasing suction pressure by 3 to 5 psig Slowly open the suction valve until the suctio
31. 11 4 14 HUMIDITY SENSOR CHECKOUT 4 11 4 15 SUCTION AND DISCHARGE PRESSURE TRANSDUCER CHECKOUT 4 11 4 16 REPLACING SENSORS AND TRANSDUCERS 4 12 4 17 SERVICING MAIN EVAPORATOR BLOWER ASSEMBLY 4 12 4 18 ACCESSING MAIN EVAPORATOR MOTOR BRUSHES 4 12 4 19 SERVICING MOTOR BRUSHES 4 12 4 20 SERVICING THE MAIN EVAPORATOR AND HEATER COIL 4 13 4 21 REMOVING THE CONDENSER ASSEMBLY 4 13 4 22 SERVICING THE CONDENSER COIL 4 13 4 23 SERVICING THE CONDENSER MOTOR 4 13 4 24 SERVICING THE DRIVER CONTROL 4 13 425 SERVICING THE DRIVER EVAPORATOR 4 14 4 25 1 Access Cover Removal 4 14 4 25 2 Blower Hemoval Deng eec ac hee ig Cari ace e e NEE 4 14 4 25 3 Air filter Bierrioval eae Mere ERO ME RR Ed 4 14 4 25 4 Removal of Evaporator Heater Coil Assembly 4 14 4 25 5 RAM Air Actuator Removal 4 14 4 26 SERVICING THE PARCEL RACK EVAPORATOR
32. 300 psig 20 41 BAR 2 3 6 Passenger Area Evaporator Fan Speed Selection The passenger area evaporator assembly is equipped with a two speed fan motor Temperature control is the primary method of determining the fan speed selection Table 2 1 indicates relay operational status for the various fan motor states Table 2 1 Main Evaporator Fan Speed Relay Operation HIGH SPEED LOW SPEED STATE RELAY ff RELAY Pull 2 3 7 Driver s Area Evaporator Fan Speed Selection The driver air conditioning unit is equipped with two evaporator fan motors The Defrost slide switch determines the fan speed See Figure 2 1 2 3 8 Condenser Fan Speed Control The first condenser fan motor CM1 is energized when the compressor clutch output is energized The second condenser fan motor CM2 is energized when the clutch is energized and the discharge pressure increases above 175 psig 1 2 mkPa It will be de energized when the clutch is de energized or the discharge pressure decreases below 125 psig 0 861 mPa The condenser fans are started in low speed and will remain in low speed until the discharge pressure increases above 225 psig 1 6 mPa The fans will remain in high speed until the discharge pressure decreases below 165 psig 1 1 mPa Off On On n 312 2 3 9 Staging When the system is started the fans are staged on to reduce the total starting current There is no staging required for the driver evaporator
33. 320 3 602 4 16 REPLACING SENSORS AND TRANSDUCERS a Turn main battery disconnect switch to OFF position and lock b Tag and disconnect wiring from defective sensor or transducer c Remove and replace defective sensor or transducer d Connect wiring to replacement sensor or transducer e Checkout replacement sensor or transducer Refer to paragraph 4 13 4 15 or 4 14 as applicable 4 17 SERVICING MAIN EVAPORATOR BLOWER ASSEMBLY a Turn main battery disconnect switch to OFF position and lock b Remove access door located in the 3 baggage compartment To remove the access door unlatch then open the door enough to slide the hinge pins out of the pin brackets c Disconnect electrical connections to the motor T 312 Remove blower transitions ducts Remove the four bolts securing the evaporator motor mounting plate motor and blower housing assembly to the bottom panel Remove motor and blower wheel assembly by sliding out of evaporator housing Repair or replace any defective component s as required Replace by reversing steps b thru f 0 h 4 18 ACCESSING MAIN EVAPORATOR MOTOR BRUSHES Turn main battery disconnect switch to OFF position and lock Remove access door Refer to 4 17 b Disconnect electrical connections to the motor With a marker trace the outline of the motor on the motor plate Remove the four brush access doors on the motor Servic
34. 4 4 Refrigerant Removal From Compressor 4 3 Refrigerant Service Connections 4 5 Refrigeration System Components 1 9 Replacing High Pressure Switch 4 7 Index 1 T 312 INDEX 5 Safety Devices 1 10 Safety Summary General i Temperature Pressure Chart 4 15 Schematic Diagram 5 3 5 4 5 5 Servicing Motor Brushes 4 12 Suction and Discharge Service Valves 4 1 Thermostatic Expansion Valve 4 7 Temperature Sensor 4 11 Superheat Check Measure 4 8 TroubleShooting 3 1 System Pumpdown 4 2 System Service 4 1 Troubleshooting Proceedures 3 5 T 312 Index 2
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36. CYLINDER WITHOUT A PRESSURE REGULATOR DO NOT USE OXYGEN IN OR NEAR A REFRIGERATION SYSTEM 5 AN EXPLOSION MAY OCCUR Remove switch from unit All units are equipped with schrader valves at the high pressure switch connection b Connect an ohmmeter across switch terminals If the Switch is good the ohmmeter will indicate continuity indicating that the contacts are closed Cylinder Valve and Gauge Pressure Regulator Nitrogen Cylinder Pressure Gauge 0 to 400 psig 0 to 2 8 mPa Bleed Off Valve 1 4 inch Connection Figure 4 5 Checking High Pressure Switch c Connect switch to a cylinder of dry nitrogen See Figure 4 5 d Set nitrogen pressure regulator higher than cutout point on switch being tested Refer to paragraph 1 3 e Open cylinder valve Slowly open the regulator valve to increase the pressure until it reaches cutout point The switch should open which is indicated by an infinity reading on an ohmmeter no continuity 4 7 f Close cylinder valve and release pressure through the bleed off valve As pressure drops to cut in point the switch contacts should close indicating continuity on the ohmmeter 4 10 FILTER DRIER 4 10 1 To Check Filter Drier Check for a restricted or plugged filter drier by feeling the liquid line inlet and outlet connections of the filter drier If the outlet side feels cooler than the inlet side then the filter drier should be changed 4 10 2 To Replace Filter
37. Carrier Transicold Transport Air Conditioning 68G5 105 SERIES MCI J4500 COACH Operation amp Service T 312 Rev TRANSICOLD OPERATION AND SERVICE MANUAL TRANSPORT AIR CONDITIONING EQUIPMENT Model 68G5 105 Series for MCI J4500 Model Coach Carrier Transport Refrigeration and Air Conditioning Ame amber onne Un ied Te ologes 5 Cor family E GC symbol UTX Carrier Transicold Carrier Corporation P O Box 4805 Syr e N Y 13221 U S A 2003 CarrierCorporation Printed U 5 0903 2 Carrier A United Technologies Company SAFETY SUMMARY GENERAL SAFETY NOTICES The following general safety notices supplement the specific warnings and cautions appearing elsewhere in this manual They are recommended precautions that must be understood and applied during operation and maintenance of the equipment covered herein The general safety notices are presented in the following three sections labeled First Aid Operating Precautions and Maintenance Precautions A listing of the specific warnings and cautions appearing elsewhere in the manual follows the general safety notices FIRST AID An injury no matter how slight should never go unattended Always obtain first aid or medical attention immediately OPERATING PRECAUTIONS Always wear safety glasses Keep hands clothing and tools clear of the evaporator and condenser fans No work should be performed on the unit un
38. Drier a Pump down the unit Refer to paragraph 4 4 b Replace filter drier ensuring that the arrow points in the direction of the refrigerant flow c Drier can be evacuated at liquid line service valve See Figure 4 4 d Check refrigerant charge Refer to paragraph 4 7 1 Power Head Assembly Equalizer Connection Bulb Cage Assembly Seat Gasket Body Flange Capscrew Body Flange Gasket Figure 4 6 Thermostatic Expansion Valve 4 11 THERMOSTATIC EXPANSION VALVE The thermostatic expansion valve TXV is an automatic device which maintains constant superheat of the refrigerant gas leaving the evaporator regardless of suction pressure The valve functions are a automatic response of refrigerant flow to match the evaporator load and b prevention of liquid refrigerant returning to the compressor Unless the valve is 1 2 3 4 5 6 7 8 defective it seldom requires any maintenance All TXV s are non adjustable 4 11 1 Replacing the Expansion Valve See Figure 4 6 a down low side of the unit Refer to paragraph 4 4 b Remove insulation Presstite from expansion valve bulb T 312 Loosen retaining straps holding bulb to suction line and detach bulb from the suction line Loosen flare nut on equalizer line and disconnect equalizer line from the expansion valve e Remove capscrews and lift off power head and cage assemblies and gaskets f Check clean and remove an
39. Ds will be illu minated When a fan speed is selected the appropri ate LED will be illuminated 11 F C Key combination is used to select F or C When the display is showing temperature press and hold the Inside Outside Temperature selection key 8 and press the UP key 2 the display will show in the F scale When the display is showing temperature press and hold the Inside Outside Temperature selection key 8 and press the DOWN key 3 the display will show in the C scale Figure 2 2 Parcel Rack On Off d The Parcel Rack Switch Figure 1 9 controls the liq uid line solenoid valve and the blower motors of the parcel rack evaporators The driver controls the par cel rack evaporator function with this switch The par cel rack evaporators will function only after the main evaporator is operating T 312 Figure 2 3 Driver A C e The Driver A C Switch Figure 2 3 allows the driver to control cooling with the driver s evaporator When the switch is in AUTO the driver s area cooling is controlled by the microprocessor controller When the switch is in COOL the driver s area is demanding cooling even if the microprocessor is calling for heat ing in the passenger area 2 1 2 HVAC Power to Controller Before starting the system electrical power must be available from the coach power supply 2 1 3 Starting The Driver Display Panel consists of a display and a keypad Figure 2 1 which allows the u
40. Electrical Schematic Diagram 5 4 5 4 Electrical Schematic Diagram 5 5 LIST OF TABLES Table Page 1 1 Part Model Number Chart 1 1 1 2 Additional Support Manuals 1 1 1 3 Safety Devices Within Carrier Supplied Equipment 1 10 2 1 Main Evaporator Fan Speed Relay Operation 2 5 2 2 Main Area Staging pee pacha REIR RR ERE RR DE pale pales 2 6 3 1 Microprocessor Error Message Definition 3 1 3 2 Display Error Message Definition 3 1 3 3 Driver Display Panel Alarm Message Definition 3 1 9 4 Parameter Codes ibd sees eed node a E 3 4 3 5 General System Troubleshooting Procedures 3 5 4 1 Checking Refrigerant Charge 4 2 Checking Refrigerant Charge 4 3 Temperature Sensor AT and TSR Resistance 4 11 4 4 Humidity Sensor HS Voltage 4 11 4 5 Suction and Discharge Pressure Transducer
41. Flow Air flow through coil blocked Coil frosted over Defrost coil Dirty coil Clean Dirty filter Clean Replace No or partial evaporator air flow Motor running in reverse Check Motor s defective Repair Replace Motor brushes defective main evaporator 4 18 4 19 Evaporator fan loose or defective Repair Replace Fan damaged Repair Replace Return air filter dirty Clean Replace Icing of coil Clean Defrost Fan relay s defective Check Replace Safety device open 1 6 3 3 7 Expansion Valve Malfunction Low suction pressure with high Low refrigerant charge 4 5 and 4 7 superheat Wax oil or dirt plugging valve orifice 4 6 Ice formation at valve seat 4 6 Power assembly failure 4 11 1 Loss of bulb charge 4 11 1 Broken capillary 4 11 1 Low superheat and liquid slugging Superheat setting too low 4 11 Ice or other foreign material holding valve open 3 3 8 No Or Insufficient Heating Insufficient heating Dirty or plugged heater core Clean Coolant solenoid heat valve s malfunctioning or plugged Check Replace Low coolant level Check Coolant bypass heat valve open or malfunctioning Check Replace Strainer s plugged Clean Hand valve s closed Open Water pumps defective Repair Replace Auxiliary Heater malfunctioning Repair Replace No Heating Coolant solenoid heat valve s malfunctioning or plugged Check Replace Microprocessor malfunction Replace Pump s malfunctioning Repair Replace Safety device open 1 6 NOTE Refer to Model 05G Compressor
42. ING MODE COMPR FULLY LOADED 6 CYL 8 F 4 5 C COOLING MODE LOW SPEED MAIN EVAP FAN COMPR FULLY LOADED 6 CYL 6 75 F 3 75 C COOLING MODE LOW SPEED MAIN EVAP FAN COMPR SEMI LOADED 4 CYL 5 5 F 3 0 C REHEAT MODE HUMIDITY LESS THAN 49 LOW SPEED MAIN EVAP FAN OMPR UNLOADED 2 CYL OR HUMIDITY CONTROL MODE SET POINT HUMIDITY GREATER TAN 50 HIGH SPEED MAIN EVAP FAN COMPR FULLY LOADED 6 CYL 3 5 F 2 0 C HEAT MODE LOW SPEED MAIN EVAP FAN COMPR FULLY UNLOADED CLUTCH DISENGAGED 8 F 4 5 C HEAT MODE COMPR FULLY UNLOADED CLUTCH DISENGAGED 8 5 F 475 C HEAT MODE HIGH SPEED MAIN EVAP FAN COMPR FULLY UNLOADED CLUTCH DISENGAGED FALLING TEMP RISING TEMP For humidity control refer to 2 3 4 Figure 2 4 Main Controller Automatic Control Sequence b Cooling Reheat Cooling and reheat require various combinations of evaporator fan speeds and compressor unloading Cooling is accomplished by energizing the compressor and condenser opening the liquid solenoid valve and T 312 closing the heating valve The compressor clutch and condenser fan motors are energized as appropriate Reheat allows for both net cooling and net heating by varying the time that the heat valve is open The time is automatically calculated by the controller and is based on a 20 second period c Heating In the heat capacity state the liquid solenoid valve is closed to stop
43. LATOR WARNING DO NOT USE OXYGEN IN OR NEAR A REFRIGERATION SYSTEM AS AN EXPLOSION MAY OCCUR WARNING EXTREME CARE MUST BE TAKEN TO ENSURE THAT ALL THE REFRIGERANT HAS BEEN REMOVED FROM THE COMPRESSOR CRANKCASE OR THE RESULTANT PRESSURE WILL FORCIBLY DISCHARGE COMPRESSOR OIL WARNING WHEN MOVING THE COIL CARE MUST BE TAKEN TO AVOID PERSONAL INJURY BE CAUSE OF THE WEIGHT OF THE COIL CAUTION Do not under any circumstances attempt to service the microprocessor Should a problem develop with the microprocessor replace it CAUTION Care Must Be Taken To Ensure That The Manifold Common Connection Remains Immersed In Oil At All Times Or Air And Moisture Will Be Drawn Into The System CAUTION To prevent trapping liquid refrigerant in the manifold gauge set be sure set is brought to suction pressure before disconnecting T 312 Safety 2 TABLE OF CONTENTS Section Page SAFELY SUMMARY sz ustus DESCRIPTION eh 1 1 Ta INTRODUCTIONS iei Ee ep E MERE u SS M 1 1 1 2 GENERAL DESCRIPTION ERE REL E au MEI LME A 1 2 1 2 1 Condenser Assembly 1 2 1 2 2 Compressor Assembly 1 4 1 2 3 Evaporator Assemblies ee Rede et 1 4 1 2 4 Main Control BOX tex Seca D Erga
44. ROLLER INPUT SENSORS AND TRANSDUCERS a Suction and Discharge Pressure Transducer Supply Voltage 4 5 to 5 5 vdc 5 vdc nominal Input Range 6 7 to 450 psig 0 05 to 30 62 BAR Output Voltage vdc 0 0098 x psig 0 4659 See Table 4 5 for calculations b Temperature Sensors Input Range 52 6 to 158 F 47 to 70 C Output NTC 10K ohms at 77 F 25 C See Table 4 3 for calculations T 312 1 6 SAFETY DEVICES System components are protected from damage caused by unsafe operating conditions with safety devices Safety devices that are connected to Carrier Transicold supplied equipment include a high pressure switch HPS fuses See Table 1 3 and a fusible plug In addition evaporator and condenser fan motors and the main control box are protected independently against high current draw by circuit breakers supplied by the coach manufacturer The evaporator and condenser fan motors are also protected from high temperature with internal thermal protection switches If acondenser fan motor safety device opens to stop the condenser fan motor s the system may develop a high pressure condition which may open the high pressure switch HPS to shut the unit down a Pressure Switches High Pressure Switch HPS The high pressure switch HPS is installed in the compressor center cylinder head and opens on a pressure rise to shut down the system when high pressure conditions occur Refer to 1 3 d During the A C
45. SPT and DPT Voltage 4 12 4 6 R 134a Temperature Pressure 4 15 T 312 iv SECTION 1 DESCRIPTION 1 1 INTRODUCTION This manual contains Operating and Service Instructions and Electrical Data for the Model 68G5 105 Coach Air Conditioning and Heating equipment furnished by Carrier Transicold Division for the MCI J Series Intercity coach Table 1 1 provides a model number chart The Model 68G5 105 equipment see Figure 1 1 consist of a condenser a main evaporator with integral heater a driver evaporator with integral heater optional parcel rack evaporators compressor assembly main control box driver display panel check valve assembly temperature sensors and a bypass heat valve The 68G5 air conditioning and heating equipment interfaces with electrical cabling a parcel rack evaporator thermostat kit refrigerant piping engine coolant piping ductwork and other components furnished by the coach manufacturer to complete the system Table 1 1 Part Model Number Chart Modei No Refrigerant Controller Fan Motors Parcel Rack Connection 6865 05 R t34a 24VDC Table 1 2 Additional Support Manuals Driver Evaporator Driver Evaporator Control Box Parcel Rack Evaporator 27 Main Evaporator Driver Display Panel gt Curbside Return Air Temperature and Humidity Sensor fs t D Check Valve Main Control B
46. T 312 Place temperature thermocouple contact with the suction tube and parallel to the TXV bulb and then secure loosened clamp making sure both bulbs are firmly secured to suction line See Figure 4 7 Reinstall insulation around the bulb e Connect an accurate low pressure gauge or installa manifold gauge set to the service port on the leaving side of the evaporator Refer to paragraph 4 3 f Close evaporator access door being careful to route thermocouple sensing wire and guage hose thru the access hole to outside the evaporator g Start coach and run on fast idle until unit has stabilized about 20 to 30 minutes h From the temperature pressure chart determine the saturation temperature corresponding to the evaporator outlet pressure Refer to Table 4 6 Note the temperature of the suction gas at the expansion valve bulb Subtract the saturation temperature determined in step 8 from the temperature measured in this step The difference is the superheat of the suction gas j Repeat steps 8 and 9 six times at three minute intervals and average the six readings to determine average superheat Average superheat should be 12 to 18 F 6 7 to 10 1 C 4 12 MODEL 05G COMPRESSOR MAINTENANCE 4 12 1 Removing the Compressor If compressor is inoperative and the unit still has refrigerant pressure isolate the compressor and remove the refrigerant Refer to paragraph 4 4 3 If compressor is operativ
47. are de voltage is greater than place alternator energized 17 vdc A29 Low Voltage Power 12 vdc source Repair or replace All microprocessor outputs are de voltage is less than 10 wiring or alternator energized vdc A31 EEPROM Memory failure Replace main micro Modifies out of range values to their processor at next ser default values vice stop Table 3 4 Parameter Codes CODE CODE NAME DESCRIPTION Suction Pressure This value is the suction pressure measured by the suction pressure transduc er If the sensor is shorted it will display CL If it is open circuited it will display OP NOTE This value is not updated it is the value at the time that the code is accessed Discharge Pressure This value is the discharge pressure measured by the discharge pressure transducer If the sensor is shorted it will display CL and if it is open circuited it will display DP NOTE This value is not updated it is the value at the time that the code is accessed P20 Compressor Hours This is the number of hours of operation that the compressor has run with the H clutch energized The reading is in thousands igh Compressor Hours This is the number of hours of operation that the compressor has run with the Low clutch energized The reading is in hundreds tens and ones OW Evaporator Hours This is the number in thousands of hours of operation with the evaporator High fans energized Evaporator Hours This is the number i
48. ata Flow Block Diagram 1 14 2 1 System Operating Controls upper left hand switch panel 2 2 Parcel Rack On Off 2 3 DEIVer AIO out eee etat uie rien salen 2 2 2 4 Main Controller Automatic Control Sequence 2 4 4 1 Suction or Discharge Service Valve 4 1 4 2 Manifold Gauge Set R 134a 4 2 4 3 Compressor Service Connections 4 3 4 4 Refrigerant Service Connections 4 5 4 5 Checking High Pressure 4 7 4 6 Thermostatic Expansion 4 7 4 7 Thermostatic Expansion Valve Bulb and Thermocouple Installation 4 8 4 8 Removing Bypass Piston 0 0 4 9 4 9 Model O5G Compressor 4 9 4 10 Removing Driver Control BOX 4 13 5 1 Electrical Schematic Diagram Legend and Symbols 5 2 5 2 Electrical Schematic Diagram 5 3 5 3
49. ay frost Allow the part to warm to ambient temperature before dismantling this avoids internal condensation which puts moisture into the system When opening or closing the service valves care should be given to note if the packing around the valve stem is worn or may need adjustment to prevent refrigerant leaks 4 4 3 Refrigerant Removal From An Inoperative Compressor To remove the refrigerant from a compressor that is not operational do the following a Attach a manifold gauge set as shown in Figure 4 3 and isolate the compressor by front seating the suction and discharge valves b Recover refrigerant with a refrigerant reclaimer If the discharge service valve port is not accessible it will be necessary to recover refrigerant through the suction service valve port only c Service or replace components as required and leak check the compressor d Using refrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge set Evacuate compressor to 500 microns Close off pump valve isolate vacuum gauge eee pump Wait 5 minutes to verify that vacuum olds Once vacuum is maintained recharge low side with R 134a to 20 to 30 PSIG by admitting vapor from the refrigerant cylinder Backseat compressor service valves and disconnect manifold gauge set Discharge Service Valve and Port Suction Service Valve and Port Manifold Gauge Set 4 Vacuum Pump 5 Reclaim
50. b Remove and reclaim the entire refrigerant charge Refer to paragraph 4 4 2 c Turn main battery disconnect switch to OFF position and lock d Disconnect all electrical leads to the module e Disconnect refrigerant lines to the module f Remove the door latch stud to the right side of the condenser compartment g Remove the front panel and the eight screws fastening the condenser to the coach h Remove the stabilizing bracket on the top of the condenser i Remove the eight screws securing the condenser door hinges to the frame j Remove condenser module by sliding out on mounting rails 4 22 SERVICING THE CONDENSER COIL a Remove the condenser assembly from the coach Refer to paragraph 4 21 b Remove side panel with control box c Remove front shroud and panel assemblies d Unbraze coil tubing connections and roll front module assembly forward to provide clearance for coil removal e Remove condenser coil f Repair or replace the condenser coil g Re install by performing the above procedure in reverse 4 23 SERVICING THE CONDENSER MOTOR a Turn main battery disconnect switch to OFF position and lock b Remove appropriate front condenser grill Remove fan blade secure the shaft key to the motor shaft or fan hub slot Disconnect the wires to the motor Remove the four motor base mounting screws Remove the motor and place on workbench Repair or replace defective componen
51. ccess valve cap 2 Connect the field service coupler see Figure 4 2 items 5 and 6 to the access valve 3 Turnthe field service coupling knob clockwise which will open the system to the gauge set 4 Read system pressures 5 Repeat the procedure to connect the other side of the gauge set c Removing the Manifold Gauge Set 1 While the compressor is still ON backseat the high side service valve 2 Midseat both hand valves on the manifold gauge set and allow the pressure in the manifold gauge set to be drawn down to low side pressure This returns any liquid that may be in the high side hose to the system CAUTION To prevent trapping liquid refrigerant in the manifold gauge set be sure set is brought to suction pressure before disconnecting 3 Backseat the low side service valve Backseat both field service couplers and frontseat both manifold set hand valves Remove the couplers from the access valves 4 Install both service valve stem caps and access valve caps finger tight only 4 4 PUMPING THE SYSTEM DOWN OR REMOVING THE REFRIGERANT CHARGE NOTE To avoid damage to the earth s ozone layer use a refrigerant recovery system whenever removing refrigerant 4 4 4 System Pumpdown To service or replace the filter drier expansion valve evaporator coil or suction line pump the refrigerant into condenser coil as follows a Install manifold gauge set Refer to paragraph 4 3 b Startthe unit and al
52. communications to transmit data to the display The communications link is RS232 SECTION 3 TROUBLESHOOTING CAUTION Do not under any circumstances attempt to service the microprocessor Should a problem develop with the microprocessor replace it NOTE To access LED display on the microprocessor remove cover from main control box located in rear of electrical compartment Table 3 1 Microprocessor Error Message Definition ERROR STATUS OF CODE LED DISPLAY REMEDY 0 1 1 Not Applicable as system is operating normally Record error code number tag and replace the microprocessor Record error code number tag and replace the microprocessor Record error code number tag and replace the microprocessor Record error code number tag and replace the microprocessor Record error code number tag and replace the microprocessor 6 6 flashes 5 sec pause Record error code number tag and replace the microprocessor Table 3 2 Display Error Message Definition ERROR CODE MESSAGE MESSAGE DEFINITION If the display does not receive data from the microprocessor If memory on the display is not verified on power up Program Memory If program memory on the display is not verified on power up by a checksum Table 3 3 Driver Display Panel Alarm Message Definition atum TITLE CAUSE REMEDY MICROPROCESSOR RESPONSE All Main Left Sensor is unplugged Ensure sensor is Switches to the right probe If both Pr
53. control output devices enabling automatic control of temperature conditions inside the coach The driver display provides a communication link between the main controller and the rest of the system The following block diagram Figure 1 13 indicates data flow through the system Refer to section 2 for more detailed information on the theory of operation of the control system and see section 5 for system electrical schematics 24 VDC 12 24 VDC POWER POWER SUPPLY SUPPLY INPUT OUTPUT DEVICES DEVICES Sch Motors Transducers MAIN CONTROLLER gt Solenoids gt Driver Conti j Sensors and Relays Br ontro HP switch Clutch Ox 12 VDC POWER T DRIVER _ EXPANSION re D Valves and RAM Air Actuators MAIN CONTROL BOX 24 VDC POWER SUPPLY Figure 1 13 Electronic Automatic Control Data Flow Block Diagram T 312 SECTION 2 OPERATION Defrost Driver s Evap Blower a Up Increase Selection 2 Automatic Control 4 Driver Display Panel cC Down Decrease Selection 3 Vent Only 6 f e Carrier re TRANS ICOLD AUTO 5 x U Heat Driver s Evap Coolant Valve b On Off 1 Dis
54. e perform a pump down Refer to paragraph 4 4 4 a Turn main battery disconnect switch to OFF position and lock b Loosen the compressor drive belt and remove Loosen bolts at suction and discharge service valve flanges and break seal to be sure pressure is released Remove bolts from suction and discharge service valve flanges e Tag and disconnect wiring to the high pressure cutout switch discharge pressure transducer suction pressure transducer unloaders and the clutch f Remove four bolts holding compressor to base Attach sling or other device to the compressor and remove compressor from the coach through the right rear access door 2 Set the compressor on a sturdy work surface 4 12 2 Re installing the Compressor NOTES 1 service replacement 05G compressors are sold without shutoff valves Valve pads are installed in their place The optional unloaders are not supplied as the cylinder heads are shipped with plugs The customer should retain the original unloader valves for use on the replacement compressor The piston plug that is removed from the replacement compressor head must be installed in the failed compressor if returning for warranty Do not interchange allen head capscrews that mount the piston plug and unloader they are not interchangeable Check oil level in service replacement compressor Refer to paragraphs 1 3 and 4 12 4 Service replaceme
55. e 2 6 TABLE OF CONTENTS Continued Section Page 2 9 15 Alarm 0656 42214224 RE eic o eed eee te obs a ee eed 2 6 2 9 16 Flour Meters 2 EIS ne an pO LLEVE EC 2 6 2 3 17 Communications Driver Display Controller 2 6 TROUBLESHOOTING ee See Bregen 3 1 23 91 System Will Not GOO pata hu bee aa SPR e I Paden RII E Mae 3 5 3 3 2 System Runs But Has Insfficient Cooling 3 5 3 3 3 Abnormal Pressures cs eee dates cay dene PERROS 3 5 3 3 4 Abnormal Noises Or Vibrations 3 5 3 3 5 Control System 3 6 3 3 6 No Evaporator Air Flow Or Restricted Air Flow 3 6 3 3 7 Expansion Valve Malfunction 3 6 3 3 8 No Or Insufficient Heating 3 6 SERVICE ee a iat een 4 1 41 MAINTENANCE 4 1 4 2 SUCTION AND DISCHARGE SERVICE VALVES 4 1 43 INSTALLING MANIFOLD GAUGES 4 2 4 3 1 Installing R 134a Manifold Guage 4 2 4 4 PUMPING THE SYSTEM DOWN OR REMOVING THE REFRIGERANT CHARGE
56. e two brushes top front and top rear Remove the four bolts securing the evaporator motor to the mounting plate Rotate the motor to gain access to the lower front brush Rotate the motor the opposite way to gain access to the lower rear brush j Rotate the motor back to its feet and position back to its original position guided by the outline drawn in step d 2 Re secure the motor with the four bolts removed in step g Check fan rotation insuring that the fan wheels do not make contact with the fan housings Complete the procedure by performing steps a thru c in reverse 4 19 SERVICING MOTOR BRUSHES If the brushes are broken cracked severely chipped or worn to 1 3 their original length replace them a Remove the four brush access doors on the motor b With fingers or a suitable hook lift the brush spring end up so the brush may slide up and out of the holder Loosen the brush screw to remove the brush shunt terminal Remove the brush Toreplace lift the brush spring and place the brush in the holder Position the end of the spring on top of the brush Connect the brush shunt terminal to its proper crossover with the brush screw assembled loosely NOTE Assure positioning of the brush to permit the brush shunt to travel freely in the holder slot as the brush wears If the brush hangs up commutator damage and motor failure will result Tight
57. efrigerant gas and forces it into the condenser tubes The clutch assembly provides a means of belt driving the compressor by the coach engine The suction and discharge service valves enable servicing of the compressor Suction and discharge access charging ports mounted on the service valves enable connection of charging hoses for servicing of the compressor as well as other parts of the refrigerant circuit Transducers convert refrigerant pressures into electrical signal inputs which are sent to the main controller The high pressure switch HPS is a normally closed switch its contacts open on a pressure rise to shut down the system when abnormally high refrigerant pressures occur The electric unloaders provide a means of controlling compressor capacity which enables control of temperature inside the coach For more detailed information on the compressor refer to manual number 62 02756 1 2 3 Evaporator Assemblies The evaporator assemblies include a driver evaporator assembly See Figure 1 4 main evaporator assembly See Figure 1 6 and may include two parcel rack evaporator assemblies See Figure 1 5 The driver evaporator assembly includes an evaporator coil assembly a thermal expansion valve a heater coil assembly an evaporator heat valve EHV two fan and T 312 motor assemblies an air filter and two condensate drain connections The evaporator heat valve EHV for the driver evaporator is installed in the pipi
58. en opened to replace or repair a component To check for leaks in the refrigeration system perform the following procedure NOTE It must be emphasized that only the correct refrigerant drum should be connected to pressurize the system Any other gas or vapor will contaminate the system which will require additional evacuation Ensure all the service valves and solenoid valves are open It will be necessary to energize the solenoid valves from an external power source b Ifthe system is without refrigerant charge the system with refrigerant vapor to build up pressure between 30 to 50 psig 2 74 to 3 40 BAR Add sufficient nitrogen to raise system pressure to a maximum of 150 psig 10 21 BAR Check for leaks It is recommended that an electronic leak detector be used to find refrigerant leaks a system Testing joints with soapsuds is satisfactory and may be necessary under conditions when an electronic leak detector will not function correctly Remove refrigerant from system and repair any leaks f Evacuate and dehydrate the system Refer to paragraph 4 6 Charge the unit Refer to paragraph 4 7 Ensure that self test has been performed and that there are no errors or alarms indicated Refer to paragraphs 2 1 5 and 2 1 6 4 6 EVACUATION AND DEHYDRATION 4 6 1 General The presence of moisture in a refrigeration system can have many undesirable effects The most common are copper plating acid sl
59. en screw 4 20 SERVICING THE MAIN EVAPORATOR AND HEATER COIL a Drain engine coolant from the heater coil b Pump down low side of the HVAC system Refer to paragraph 4 4 1 c Remove remaining refrigerant Refer to paragraph 4 4 d Remove the evaporator motor by following paragraph 4 17 steps a thru f e Disconnect all remaining electrical connections move wires out of the way f Remove the evaporator electrical panel assembly g Remove the liquid line 8 connection points and the discharge line 2 connection points that pass thru the evaporator and connect to the evaporator h Disconnect and remove the suction line i Disconnect and remove the heater hoses j Remove the door frame surrounding the evaporator enclosure k Remove the four bolts that secure the coil bracket to the drain pan Leave the coil bracket bolted to the evaporator coil until the coil has been removed from the coach WARNING WHEN MOVING THE COIL CARE MUST BE TAKEN TO AVOID PERSONAL INJURY BECAUSE OF THE WEIGHT OF THE COIL Brace the top of the coil hold it in position m Remove the four bolts that secure the top of the coil to the evaporator housing n Rotate the top of the coil till the coil is horizontal and slide out of the evaporator housing o Re install by performing the above procedure in reverse 4 21 REMOVING THE CONDENSER ASSEMBLY a Remove two side access panels from rear of the last baggage bay
60. er 6 Refrigerant Cylinder 7 Thermistor Vacuum Gauge Figure 4 3 Compressor Service Connections 4 4 4 Pump Down An Operable Compressor For Repair To service an operable compressor pump the refrigerant into the condenser coil as follows a Install manifold gauge set See Figure 4 3 b Unplug the suction pressure transducer SPT c Frontseat the compressor suction service valve by turning clockwise d Start the unit and run in cooling until 10 hg 0 69 BAR of vacuum is reached Shut the system down and tag out system power source Frontseat the compressor discharge service valve and wait 5 minutes to verify vacuum is maintained If the pressure rises above vacuum open the compressor discharge service valve and repeat steps c and d until a vacuum is maintained f Service or replace components as required and leak check the compressor g Using refrigerant hoses designed for vacuum service connect a vacuum pump to center connection of manifold gauge set Evacuate system to 500 microns Close off pump valve isolate vacuum gauge and stop pump Wait 5 minutes to verify that vacuum holds h Once vacuum is maintained backseat compressor Service valves and disconnect manifold gauge set i Reconnect the suction pressure transducer SPT j Ger the low pressure alarm Refer to paragraph 2 1 6 T 312 4 5 REFRIGERANT LEAK CHECK A refrigerant leak check should always be performed after the system has be
61. ers the display will first flash outthe parameter identifier Pxx for one second and then show the parameter value To return to normal operation press the On Off key see Figure 2 1 Refer to Section 3 for for definitions of the parameter codes 2 3 2 1 8 Stopping With the system operating pressing the ON OFF key will stop the HVAC system operation and the display will be blank 2 2 PRE TRIP INSPECTION After starting system operation allow system to stabilize for ten to fifteen minutes and check for the following a Listen for abnormal noises in compressor or fan mo tors b Check compressor oil level 4 12 4 c Check refrigerant level Refer to paragraph 4 7 1 Refer to paragraph d Ensure that self test has been successfully per formed and that there are no errors or alarms indi cated Refer to paragraph 2 1 5 or 2 1 6 2 3 SYSTEM DESCRIPTION Referto Section 5 for sample schematic diagrams of the power and control circuits 2 3 1 Pull Up and Pull Down Modes At power up the system will enter a pull up or pull down mode to rapidly obtain desired temperatures within the coach During this mode the system will run at maximum heating or cooling capacity until the set point in the passenger zone is reached for the first time For the driver zone temperature control is controlled by the two slide switches next to the controller See Figure 2 1 1 Pullup pulldown main evaporator fan speed is limit
62. from the air before the air passes over the coils condensate drain connections provide a means for disposing of condensate collected on the evaporator coils during cooling operation WARNING UNLESS OTHERWISE SPECIFIED WNERS Access Panel RAM Air Door Electrical Connector Liquid Inlet Connection Size 11 16 ORS Nameplate Suction Outlet Connection 1 7 16 ORS Air Bleed Valve Service Port Fan and Motor Condensate Drain Connections Solenoid Valve and Coil AirFilter Thermal Expansion Valve Evaporator Coil Assembly RAM Actuator Heater Coil Assembly Figure 1 4 Driver Evaporator Assembly 11 Suction Outlet Connection Fan and Motor Liquid Inlet Connection Motor Mount Bracket Side Access Panel Condensate Drain Connection Top Access Panel Relay Thermal Expansion Valve Thermostat Not supplied by Carrier Evaporator Coil Assembly Figure 1 5 Parcel Rack Evaporator Assembly 1 5 T 312 1 2 3 4 5 6 7 8 9 T 312
63. he discharge pressure range the system charge is adequate NOTE Many system related problems will effect System pressures Use Table 3 5 General System Troubleshooting Procedures to determine other possible causes before adding or removing refrigerant 4 7 2 Adding Full Charge a top and dehydrate system Refer to paragraph 4 6 b Place appropriate refrigerant cylinder on scales and connect charging hose from container to filter drier inlet valve Remove air from hoses Note weight of refrigerant and container Open liquid valve on refrigerant container Midseat filter drier inlet valve and allow refrigerant to flow into the unit Refer to paragraph 1 3 for correct charge e When drum weight scale indicates that the correct charge has been added close liquid line valve on drum and backseat the filter drier inlet valve 4 7 3 Adding Partial Charge NOTE Refrigerant charge is critical when adding charge to the unit do not add any more charge to the system after bubbles have been eliminated from the sight glass a Start the vehicle engine and allow the system to stabilize Refer to 4 7 1a to f b Connect charging hose from appropriate refrigerant cylinder vapor valve to compressor suction service valve Open cylinder valve and add vapor charge Under the above conditions the system is properly charged when the condenser sight glass is clear with occasional bubbles showing Add or remove refrigerant un
64. igure 4 9 4 12 5 Adding Oil with Compressor in System Two methods for adding oil are the oil pump method and closed system method NOTE Special care must be taken when working with POE oil that is used with HFC refrigerants such as R 134a as POE oil is very hygroscopic POE oil will easily absorb water Do not leave POE oil containers open to the atmosphere 4 12 5 1 Oil Pump Method a One compressor oil pump that may be purchased is a Robinair part no 14388 This oil pump adapts to one U S gallon 3 785 liters metal refrigeration oil container and pumps 2 1 2 ounces 72 5 milliliters per stroke when connected to the suction service valve port Also there is no need to remove pump from can after each use b When the compressor is in operation the pump check valve prevents the loss of refrigerant while allowing servicemen to develop sufficient pressure to overcome the operating suction pressure to add oil as necessary Backseat suction service valve and connect oil charging hose to port Crack open the service valve and remove air from the oil hose at the oil pump Add oil as necessary T 312 NOTE Allow time at least 60 seconds for the oil to flow thru to the crankcase and show on the sightglass 4 12 5 2 Closed System Method a Install manifold gauge set See Figure 4 3 b Unplug the suction pressure transducer SPT c Frontseat the compressor suction service valve by turning clockwise
65. ion system using R 134a as a refrigerant The main components of the system are the reciprocating compressor air cooled condenser coil subcooler filter drier thermostatic expansion valves liquid line solenoid valves and evaporator coils See Figure 1 12 The compressor raises the pressure and the temperature of the refrigerant and forces it through the discharge line and the check valve into the condenser tubes The condenser fan circulates surrounding air which is at a temperature lower than the refrigerant over the outside of the condenser tubes Heat transfer is established from the refrigerant inside the tubes to the condenser air flowing over the tubes The condenser tubes have fins designed to improve the transfer of heat from the refrigerant gas to the air this removal of heat causes the refrigerant to liquefy The refrigerant leaves the condenser and then flows through the subcooler which subcools the refrigerant before it enters the thermal expansion valves this reduces flash gas in the evaporator From the subcooler the liquid refrigerant passes through the liquid line King service valve and then through a filter drier where an absorbent keeps the refrigerant clean and free of water From the filter drier the liquid refrigerant then flows through the main liquid line solenoid valve to the main evaporator and thermal expansion valve and to the T 312 parcel rack evaporator solenoid valve if this option is ac
66. l illuminate and the other keypad LEDs will be active 2 1 Up Increase Selection If the set point is displayed when the Up key is pressed the display will increase set point 1 F 0 5 C Down Decrease Selection If the set point is dis played when the Down key is pressed the display will decrease set point 1 F 0 5 C Auto Auto Control Selection Pressing the Auto button illuminates the AUTO LED and signals the controller to automatically cycle to the control set point If the AUTO LED is illuminated the manual modes will be de activated the COOL VENT and HEAT LED s will not be illuminated Cool Cool Mode Selection If the COOL button is pressed the COOL LED is illuminated the system will only cool to control set point The AUTO VENT and HEAT LED s will not be illuminated Vent Ventilation Mode Selection If the VENT but tonis pressed the VENT LED is illuminated only the system fans will operate The AUTO COOL and HEAT LED s will not be illuminated Heat Heat Mode Selection If the HEAT button is pressed the HEAT LED is illuminated the system will operate in the heat mode only cycling the coolant control valves as needed to maintain set point The AUTO COOL and VENT LED s will not be illumi nated Inside Outside Temperature After start up the display shows set point The temperature display selection button will toggle the display to show bus T 312 inside or out
67. losed by the display b RAM Air Auto Mode 1 If the passenger return air temperature is greater than controller set point plus 2 F 1 1 C or less than set point minus 2 F 1 1 C the RAM air will be closed 2 Otherwise RAM air is open An exception to the above is that there is a five minute delay to open RAM air once it is closed inthe auto mode There is no delay to close RAM air 2 3 12 Startup At startup the controller will power on and perform all power up tesis 2 3 13 Input Processing The system determines correct operation by reading temperature sensors thermistors pressure transducers and the humidity sensor Refer to section 1 5 for electrical specifications for input devices and sections 1 2 1 1 2 2 and 1 2 6 for functional descriptions 2 3 14 Self Tests With the engine running self tests are automatically executed 5 indicates a data memory failure ER6 indicates a program memory failure If any of these or any other errors are displayed on the screen proceed to Table 3 1 2 3 15 Alarm Description Alarm descriptions and troubleshooting procedures are provided in section 3 2 3 16 Hour Meters An hour meter records the compressor run time in hours The maximum reading is 999 999 An Hourmeter records the total elapsed time the controller has been on in hours The maximum reading is 999 999 2 3 17 Communications Driver Display Controller The controller uses
68. low it to run in the cool mode for 15 to 20 minutes c Unplug the suction pressure transducer SPT NOTE The following procedure may have to be repeated several times to maintain the 0 to 2 psig 6 9 kPa pressure depending upon amount of refrigerant absorbed in the oil d Frontseat the liquid line King valve by turning clockwise Start system and run in cooling Stop the unit when the suction pressure reaches 1 psig 0 07 BAR Frontseat close suction service valve to trap the refrigerant in the high side of the system between the compressor suction service valve and the filter drier inlet valve The low side of the system will now be at 1 psig 0 07 BAR pressure and ready for servicing f Service or replace the necessary component on the low side of the system g Leak check connections Refer to paragraph 4 5 h Evacuate and dehydrate the low side Refer to paragraph 4 6 i Reconnect the suction pressure transducer SPT j Ger the low pressure alarm Refer to paragraph 2 1 6 4 4 2 Removing the Refrigerant Charge Connect a refrigerant recovery system to the unit at the condenser service King valve to remove refrigerant charge See Figure 4 4 Refer to instructions provided by the manufacturer of the refrigerant recovery system NOTE 1 Before opening up any part of the system a slight positive pressure should be indicated on the gauge When opening up the refrigerant system certain parts m
69. n Valve for R 134a Units 1 Main Evaporator Superheat Setting Nonadjustable 12 to 18 F 6 7 to 10 1 C MOP Setting None 2 Driver Evaporator and Parcel Rack Evaporator Superheat Setting Nonadjustable 5 to 12 F 6 7 to 10 1 C MOP Setting None 1 9 d High Pressure Switch HPS Opens at 385 10 psig 26 2 68 BAR Closes at 285 10 psig 19 39 68 BAR 1 4 ELECTRICAL SPECIFICATIONS WOUND FIELD MOTORS a Main Evaporator Heater Blower Fan Motor Bearing Lubrication Factory Lubricated additional grease not required Horsepower High Speed 1 6 7 2 kw Low Speed 0 7 0 5 kw Full Load Amps FLA High Speed 56 Low Speed 28 Operating Speed High Speed 1550 rpm Low Speed 1200 rpm Voltage 24 vdc b Driver Evaporator Heater Blower Fan Motor Bearing Lubrication Factory Lubricated additional grease not required Full Load Amps FLA 9 5 Operating Speed High Speed 3300 rpm Medium Speed 1600 rpm Low Speed 1100 rpm Voltage 24 vdc c Condenser Fan Motor Bearing Lubrication Shell Dolium R Horsepower 0 8 hp 7 072 kw Full Load Amps FLA High Speed 32 Low Speed 21 Operating Speed High Speed 1800 rpm Low Speed 1600 rpm Voltage 24 vdc d Parcel Rack Evaporator Fan Motor Bearing Lubrication Factory Lubricated additional grease not required Full Load Amps FLA 9 5 Operating Speed 3300 rpm Voltage 24 vdc 1 5 ELECTRICAL SPECIFICATIONS MAIN CONT
70. n gauge reads 32 psig The first unloader should de energize decreasing suction pressure by 3 to 5 psig to show it is operating properly To check the second unloader continue to frontseat the suction valve until 21 psig shows on the suction T 312 guage The second unloader should energize check for magnetism at the unloader coil increasing suction pressure by 3 to 5 psig f Slowly open the suction valve until the suction guage reads 28 psig The first unloader should de energize decreasing suction pressure by 3 to 5 psig to show it is operating properly g Back seat the suction service valve remove the guage s to resume normal operation 4 12 4 Compressor Oil Level NOTE The compressor should be fully loaded six cylinder operation the unit should be fully charged and the compressor crankcase should be warm to the touch D Start the unit and allow the system to stabilize Check the oil sight glass on the compressor to ensure that no foaming of oil is present after 20 minutes of operation If oil is foaming excessively after 20 minutes of operation check the refrigerant system for flood back of liquid refrigerant Correct this situation before proceeding Check the level of oil oil level sight glass immediately after shutting down the compressor The lowest level visible should be at the bottom of the sightglass and the highest level should be at the middle of the sight glass See F
71. n hundreds tens and ones of hours of operation with the L evaporator fans energized P P P P 2 2 2 This is the software version of the logic board The first two digits of the soft Controller Software ware revision are displayed Ex Revision XXYY XX is displayed after P30 p31 Version This is the software version of the logic board The second two digits of the software revision are displayed Ex Revision XXYY YY is displayed after P31 5 1 2 3 1 T 312 3 4 Table 3 5 General System Troubleshooting Procedures INDICATION REFERENCE TROUBLE POSSIBLE CAUSES SECTION 3 3 1 System Will Not Cool Compressor will not run V Belt loose or defective Clutch coil defective Clutch malfunction Compressor malfunction Check Check Replace Check Replace See Note Electrical malfunction Coach power source defective Check Repair Circuit Breaker safety device open Check Reset 3 3 2 System Runs But Has Insfficient Cooling Compressor Refrigeration system 3 3 3 Abnormal Pressures High discharge pressure Low discharge pressure High suction pressure Low suction pressure Suction and discharge pressures tend to equalize when system is operating 3 3 4 Abnormal Noises Or Vibrations Compressor Condenser or evaporator fans Abnormal pressures No or restricted evaporator air flow Expansion valve malfunction Restricted refrigerant flow Low refrigerant charge Service valves partially closed Safety device o
72. nd remove plugin sheet metal With screwdriver unfasten the last 1 4 turn fastener Draw access cover towards the rear and slide to the right e 4 25 2Blower Removal a Disconnect plugs and speed control from the blower b Undo latch and push the blower towards the rear c Drop the blower down and remove 4 25 3 Air filter Removal a With the access cover removed slide right hand side air filter towards center and turn right corner past edge b Slide left hand side filter to the right and repeat as above c Clean replace filter and re install T 312 4 25 4 Removal of Evaporator Heater Coil Assembly a Clamp off silicon hose close to the input and output end of the heater core Disconnect hose clamps and separate hose from fitting Pump down the refrigerant system paragraph 4 4 1 Disconnect liquid line solenoid valve plug Disconnect expansion valve thermal bulb attached to the 7 8 inch copper tube Disconnect 7 8 and 3 8 inch copper lines Remove screws that attach the heater core to the unit Lift evaporator coil up and pull towards the rear for removal 4 25 5 RAM Air Actuator Removal a Disconnect the plug b Remove the no 10 screw from the end of the spring on the RAM air actuator 4 26 SERVICING THE PARCEL RACK EVAPORATOR 4 26 1 Motor Removal a Disconnect the motor wires from the connector Remove the two bolts from the motor mount and remove the moto
73. ng outside the evaporator assembly In addition the driver evaporator has an actuator which controls the outside RAM air damper upon receipt of signal from the main controller The main evaporator assembly includes an evaporator and heater coil assembly a thermal expansion valve an evaporator heat valve EHV afan and motor assembly an air filter and two condensate drain connections There is also an evaporator speed fan relay EFRL which changes main evaporator fan speed upon receipt of a signal from the main controller The optional parcel rack evaporator assemblies includes an evaporator coil assembly thermal expansion valve a fan and motor assembly condensate drain connection and a return air thermostat on the road side only The evaporator coils provide a heat transfer surface for transferring heat from air circulating over the outside surface of the coil to refrigerant circulating inside the tubes thus providing cooling when required The thermal expansion valves meter the flow of refrigerant entering the evaporator coils The heating coils provide a heat transfer surface for transferring heat from engine coolant circulating inside the tubes to air circulating over the outside surface of the tubes thus providing heating when required The evaporator heat valve s EHV controls the flow of engine coolant supplied to the heating coils The fans circulate the air over the coils The air filters filter dirt particles
74. nnect manifold gauge set n Reconnect the suction pressure transducer SPT 4 12 6 Adding Oil to Service Replacement Compressor Service replacement compressors may or may not be shipped with oil If the replacement compressor is shipped without oil add oil through the oil fill plug See Figure 4 9 4 12 7 Removing Oil from the Compressor a If the lowest oil level observed in paragraph 4 12 4 step c is above middle of the sight glass on compressor crankcase oil must be removed from the compressor by performing the following procedure If lowest oil level visible is below bottom of the sightglass oil must be added to the compressor by following the procedure in paragraph 4 12 5 b Close frontseat suction service valve and pump unit down to to 5 psig 21 to 34 kPa Reclaim remaining refrigerant NOTE If oil drain plug is not accessible it will be necessary to extract oil through the oil fill plug with a siphon tube WARNING EXTREME CARE MUST BE TAKEN TO ENSURE THAT ALL THE REFRIGERANT HAS BEEN REMOVED FROM THE COMPRESSOR CRANKCASE OR THE RESULTANT PRESSURE WILL FORCIBLY DISCHARGE COMPRESSOR OIL c Remove the oil drain plug on the bottom plate of the compressor and drain the proper amount of oil from the compressor Replace the plug securely back into the compressor d Repeat step a to ensure proper oil level Table 4 3 Temperature Sensor AT TSC TSD and TSR Resistance Temperature
75. nt compressors are supplied with a suction filter sock for initial startup Ensure the filter sock is installed and removed in accordance with the instructions furnished a Remove the three socket head capscrews from both unloader valves on the side heads of the 050 compressor Remove the unloader valve and bypass piston assembly keeping the same capscrews with the assembly See Figure 4 8 The original unloader valve must be transferred to the replacement compressor The plug arrangement removed from the replacement is installed in the original compressor as a seal If piston is stuck it may be extracted by threading a socket head capscrew into top of piston A small Teflon seat ring at the bottom of the piston must be removed GASKET CAPSCREWS NOT INTERCHANGEABLE WITH CONTROL VALVE SCREWS SPRING FLANGE COVER COMPRESSOR HEAD BYPASS PISTON PLUG Figure 4 8 Removing Bypass Piston Plug Remove the high pressure switch and pressure transducer assemblies and install on replacement compressor after checking switch operation Install compressor in unit by performing steps c through g in reverse sequence It is recommended that new locknuts be used when replacing compressor Install new gaskets on service valves and tighten bolts uniformly Re install and tension the compressor drive belt e Unlock and turn main battery disconnect switch to ON j k position Attach two lines
76. obe Failure wiring defective or plugged in Check probes are bad the microprocessor main left evaporator sensor resistance or will run in the full reheat and evapo return air temperature wiring Replace sen rator fans will operate on low speed sensor failure sor Or repair wiring The compressor will operate on six Refer to section 4 13 cylinders if pressures permit and Table 4 3 Main Right Sensor is unplugged Ensure sensor is Switches to the left probe If both Probe wiring defective or plugged in Check probes are bad the microprocessor Failure main right evaporator sensor resistance or will run in the full reheat and evapo return air temperature wiring Replace sen rator fans will operate on low speed sensor failure sor Or repair wiring The compressor will operate on six Refer to section 4 13 cylinders if pressures permit and Table 4 3 3 1 T 312 Table 3 3 Driver Display Panel Alarm Message Definition Continued SE TITLE CAUSE REMEDY MICROPROCESSOR RESPONSE 14 Ambient Probe Failure Suction Press ure Transducer Failure Humidity Transducer Failure Fuse Blown Alarm A Discharge Pressure Transducer Failure 15 16 17 18 19 A Main Evaporator Fan Overload A22 Condenser Fan Overload T 312 Sensor is unplugged wiring defective or ambient temperature sensor failure Sensor is unplugged wiring defective or suction pressure trans ducer failure Sensor is unpl
77. ox Condenser Roadside Return Air Temperature Sensor Bypass Heat Valve Compressor Assembly INDICATES COMPONENTS FURNISHED BY THE COACH MANUFACTURER Figure 1 1 Coach Cutaway View 1 1 T 312 1 2 GENERAL DESCRIPTION 1 2 1 Condenser Assembly The condenser assembly See Figure 1 2 includes a condenser coil fan and motor assemblies filter drier sight glass control box liquid line solenoid valve s king valves and an ambient temperature sensor The condenser coil provides a heat transfer surface for condensing refrigerant gas at a high temperature and pressure into a liquid at high temperature and pressure The condenser fans circulate ambient air across the outside of the condenser tubes at a temperature lower than refrigerant circulating inside the tubes this results in condensing the refrigerant into a liquid The filter drier removes moisture and other noncondensibles from the liquid refrigerant before it enters the thermal expansion valves in the evaporator assemblies 1 The condenser is also fitted with a fusible plug which protects the system from unsafe high temperatures The control box includes condenser fan relays no 1 and no 2 CFR1 and CFR2 to enable the main controller to control operation of condenser fan motors no 1 and no 2 CM1 and 2 The control box also includes condenser speed relay no 1 CSR1 which controls the speed
78. pen Liquid solenoid valve stuck closed Refrigerant overcharge Noncondensable in system Condenser fan rotation incorrect Condenser coil dirty Suction service valve partially closed Filter drier inlet valve partially closed Filter drier partially plugged Low refrigerant charge Expansion valve malfunction Restricted air flow Compressor valve defective Loose mounting hardware Worn bearings Worn or broken valves Liquid slugging Insufficient oil Clutch loose rubbing or is defective V belt cracked worn or loose Dirt or debris on fan blades Loose mounting hardware Defective bearings Blade interference Blade missing or broken 3 5 V Belt loose or defective Check Compressor valves defective See Note 3 3 3 3 3 6 3 3 7 and 4 11 3 3 7 and 4 11 4 5 and 4 7 Open 1 6 Check Compressor valve s worn or broken See Note Low refrigerant charge 4 5 and 4 7 Compressor valve s worn or broken Open Check Open 4 10 4 5 and 4 7 3 3 7 3 3 6 See Note Check Tighten See Note See Note 3 3 7 4 12 4 Check Check Adjust Clean Check Tighten Replace Check Check Replace T 312 Table 3 5 General System Troubleshooting Procedures Continued INDICATION REFERENCE TROUBLE POSSIBLE CAUSES SECTION 3 3 5 Control System Malfunction Will not control Sensor or transducer defective 4 13 4 15 or 4 14 Relay s defective Check Microprocessor malfunction Check 3 3 6 No Evapotator Air Flow Or Restricted Air
79. play Fresh Air 9 Heat Only 7 Inside Outside Fan Speed 10 Temperature 8 Figure 2 1 System Operating Controls upper left hand switch panel 2 1 STARTING STOPPING AND OPERATING INSTRUCTIONS 2 1 1 Operating Controls 2 There are five operating controls Figure 2 1 used to control the functions of this system They are as follows 3 a The Defrost Switch controls the driver evaporator blower motor speeds With this switch the driver con trols the amount of air discharged to the windshield This function is independent of any other HVAC func tion in the coach b The Heat Switch controls the coolant valve to the driv er s evaporator With this switch the driver controls the amount of engine coolant flowing thru the driver s 5 evaporator heater core hence increasing or decreas ing the temperature of air that is discharged to the windshield This function is independent of any other HVAC function in the coach 6 c The Driver Display Panel controls the Carrier Trans icold microprocessor controller which in turn controls the operation of the heating and air conditioning sys tem With this control the driver controls the tempera 7 ture of air to the passenger area and cooling to the driver area The panel has 10 keys whose functions are described as follows 1 On Off Pressing this key will change the display state from inactive to active Ifthe controller is active 8 the display wil
80. porator service port See Figure 4 4 Connect lines to unit and manifold and make sure vacuum gauge valve is closed and vacuum pump valve is open TO speed up evacuation time open solenoid valves electrically An additional vacuum pump may be added and connected to the compressor suction service port See Figure 4 4 Start vacuum pump Slowly open valves halfway and then open vacuum gauge valve f Evacuate unit until vacuum gauge indicates 1500 microns vacuum Close gauge valve vacuum pump valve and stop vacuum pump Break the vacuum with clean dry refrigerant or dry nitrogen Use the refrigerant that the unit calls for Raise system pressure to approximately 2 psig 0 14 BAR Remove refrigerant using a refrigerant recovery system or if using nitrogen vent to atmosphere i Start vacuum pump and open all valves Evacuate unit to 500 microns vacuum j Close off pump valve isolate vacuum gauge in system and stop pump Wait five minutes to see if vacuum holds With a vacuum still in the unit the refrigerant charge may be drawn into the system from a refrigerant container on weight scales Refer to paragraph 4 7 Reclaimer Manifold Guage Set Thermistor Vacuum Guage Vacuum Pump Refrigerant Cylinder Evaporator Service Port Liquid Line King Valve and Service Port Discharge Service Port ma Discharge DRIVER SOLENOID Liquid VALVE ms Suction
81. processor controller circuit breakers and relays Modes of operation include Vent Heat Cool and Auto This control panel is located on the dashboard with the slide Switches to the left of the steering wheel In the vent mode the evaporator fans are operated to circulate air in the bus interior In the heat mode the heat valve and the OEM supplied floor blower and or boost pump are energized The evaporator fans operate to circulate air over the evaporator coil and heater coil in the same manner as the vent mode In the cooling mode the compressor is energized while the evaporator and condenser fans are operated to provide refrigeration as required The compressor is fitted with cylinder unloaders to match compressor capacity to the bus requirements Once the interior T 312 temperature reaches the desired set point the system will maintain compressor operation and open the heat valve to allow reheating of the return air In the reheat mode interior temperature is maintained at the desired set point while additional dehumidification takes place Figure 1 9 Parcel Rack On Off The forth control is the rocker switch for the Parcel Rack Figure 1 9 This switch will de activate the parcel rack evaporators if the main evaporator is in operation This switch is located on the dashboard to the right of the steering wheel The fifth control is the rocker switch for the Driver A C Figure 1 10 Itis located on the left side console
82. r c Remove the blower and motor assembly 4 26 2 Removal of Parcel Rack Evaporator Coil a Pump down the refrigerant system Refer to paragraph 4 4 1 b Remove the side access panel Disconnect expansion valve thermal bulb attached to the 7 8 inch copper tube Disconnect 7 8 and 3 8 inch copper lines Lift evaporator coil up and push towards the rear for removal b Refer to h o Table 4 6 R 134a Temperature Pressure Chart Temperature Vacuum r na ketone 746 049 sque tete RUES Temperature Lr ia raeme mar 22 cm 026 926 te pss os te Los 59 67 t 0 974 38 rt e p 18 G 157 4 15 BEE mee mo 43 1025 46 1092 s 282 es 1580 ss 2629 1846 1813 65 1978 1887 T 312 SECTION 5 ELECTRICAL SCHEMATIC DIAGRAMS 5 1 INTRODUCTION This section contains Electrical Schematic Diagrams covering the Models listed in Table 1 1 Contact your Carrier Transicold service representative or call the technical hot line at 800 450 2211 for a copy of the schematic for your specific model 5 1 T 312
83. relative humidity A reading within two percent of the values in the table would be considered good c At least one sensor lead must be disconnected from the controller before any reading can be taken Not doing so will result in a false reading Two preferred methods of determining the actual test temperature at the sensor are an ice bath at 32 F 0 C and or a calibrated digital temperature meter d If the driver display indicates that temperature at sensor is 40 F 40 C sensor could be open If driver display indicates that temperature at sensor is 127 F 52 8 C sensor could be shorted 30 0990 ss 185 80 2640 55 1155 60 1980 85 2805 40 i320 65 2445 90 2970 165 zs 245 1 4 15 SUCTION AND DISCHARGE PRESSURE TRANSDUCER CHECKOUT NOTE 1 System must be operating to check transducers 2 Both transducers are mounted on the compressor a With the system running use the driver display or manifold gauges to check suction and or discharge pressure s T 312 Use a digital volt ohmmeter to measure voltage across the transducer and compare to values in Table 4 5 A reading within two percent of the values in the table would be considered good Transducer SPT and DPT Voltage Psig Voltage Psig Voltage Psig Voltage 0 0466 115 1598 230 2720 60 1054 175 2181 290 3308 80 1250 195 2377 310 3 504 90 1348 205 2475
84. required for the passenger area the compressor and condenser will start and the main liquid line solenoid valve is opened and the heat valve is closed During reheat the main liquid solenoid valve is opened and the heating valve is opened and closed for a percentage of the heat valve period 20 seconds To enter the heat mode for the passenger area the controller must be calling the heat valve to be cycling at 51 or higher If this condition is not met the area requiring heat is put into reheat During heating the main evaporator liquid solenoid valve is closed and the heating valve is opened and closed for a percentage of the heat valve period 20 seconds Once the heat mode has been entered the controller will not re enter heat until the heat valve has closed to less than 25 A 2 3 2 Bypass Heat Valve Control The normally open Bypass Heat Valve is closed on system start up During re heat the bypass heat valve remains closed when the heat valves are open and opens 2 seconds before the heat valves close to prevent water hammering 2 3 3 Auxiliary Heater Control The auxiliary heater output is energized when the heat valve has been opened 100 for 60 seconds Once energized the auxiliary heater output is de energized when the heat valve percentage is less than 20 percent for fifteen minutes The OEM supplied Auxiliary Heater Switch located on the left side console can independently energize the auxiliary heater when
85. s 4 6 Checking High Pressure Switch 4 7 Checking Refrigerant Charge 4 6 Compressor 1 3 1 4 Compressor Oil Level 4 10 Compressor Re install 4 9 Compressor Removal 4 8 Compressor Unloaders 4 9 Condenser Assembly 1 2 4 13 Condenser Coil 4 13 Condenser Motor 4 13 D Display Error Message Definition 3 1 Driver A C Switch 1 9 2 2 Driver Control Box 4 13 Driver Display Alarm Message 3 1 Driver Display Panel 1 8 2 1 Driver Evaporator 4 14 Driver Evaporator 1 5 Driver Evaporator Blower 4 14 E Electrical Specifications Controls 1 9 Electrical Specifications Motors 1 9 Electronic Control Data Flow 1 14 Evacuation And Dehydration 4 4 Evaporator Assemblies 1 4 Evaporator Coils 1 12 Filter Drier 4 7 INDEX H Heating Flow Cycle 1 11 Humidity Control 2 5 Humidity Sensor 4 11 4 12 Installing Manifold Guages 4 2 Introduction 1 1 Main Control Box 1 7 Main Controller Auto Control Sequence 2 4 Main Evaporator Assembly 1 6 Main Evaporator Blower Assembly 4 12 Main Evaporator Or Heater Coil 4 13 Maintenance Schedule 4 1 Microprocessor Error Message Definition 3 1 O Oil Charge 1 9 Oil Adding Charge 4 10 Operating Controls 1 8 P Parameter Codes 3 4 Parcel Rack Evaporator 4 14 Parcel Rack Evaporator 1 5 Parcel Rack On Off 1 8 2 2 Pressure Transducer 4 11 4 12 R Refrigerant Charge 1 9 4 6 Refrigerant Charge Removal 4 3 Refrigerant Leak Check
86. scharge pressure at least 150 psig 10 21 BAR and stable for R 134a systems It may be necessary to partially block condenser airflow to raise discharge pressure Observe the Liquid Line Sight Glass and use the following chart to determine the condition of the refrigerant charge Table 4 1 Checking Refrigerant Charge Sight Glass Observation Condition Good Possible over charge Continue to step i Liquid present Clear of all bubbles Liquid present Occasional bubbles Good present Liquid present Possible under charge Many bubbles present Continue to step i h If the conditions in steps b thru f are met and there is still doubt about the refrigerant charge level use Table 4 2 Table 4 2 Checking Refrigerant Charge Condenser Inlet Air Discharge Pressure Temperature Range 3r BAR 60 16 110 135 7 48 9 19 65 18 120 145 8 16 9 87 80 2 150 175 1021 1191 90 3 175 200 1191 1361 i With an accurate temperature gauge measure the condenser inlet air temperature NOTE Do not use a temperature gun as it measures surface temperature and not air temperature T 312 1 If the actual discharge pressure is higher than the discharge pressure range the system may be over charged 2 f the actual discharge pressure is lower than the discharge pressure range the system may be under charged 3 If the actual discharge pressure is in t
87. ser to modify and observe system operating parameters On start up a self test will execute While the test is being executed the display will show its programing revision number in the format of X X where X is a digit from 1 to 9 ex 1 4 At his time three possible error messages may also appear on the display Refer to Table 3 2 for definitions a If the engine is not running start the engine The HVAC system will restart in the AUTO mode All sys tem controls will operate automatically in heating cooling or ventilating mode as required b CONTROL PANEL Figure 2 1 It is suggested the system be started in the automatic mode 1 The Driver Display Panel may be programmed to display the set point temperature or return air tem perature To determine which display temperature is programmed press the TEMPERATURE button so that the OUT SIDE AIR indicator is illuminated If the controller cycles back to the INSIDE AIR indicator than the controller is programmed to display return air temperature If the controller does not automati cally cycle back to the return air indicator than the controller is programmed to display set point temper ature 2 The Control Panel will signal the controller to perform start up when the ON OFF button is pushed Ensure the AUTO button indicator is illuminated If not press the AUTO button to place the system in the automat ic mode 3 If cooling only heating only or ventilation only is de
88. side temperature The inside tempera ture is obtained by averaging the curb and road side return air sensors located in the return air ducts If one sensor is not functioning the display will read only the functioning sensor if both are not function ing the display will show 40 The outside temper ature sensor is located in the condenser assembly When the key is toggled to display the inside temper ature the inside LED will be illuminated When the key is toggled to display the outside temperature the outside LED will be illuminated When the key toggles to show set point both inside and outside LEDs are turned off 9 Fresh Air The Fresh Air Button has two selection LEDs Fresh Air and Circulation If the fresh air damper door is open the Fresh Air LED is illumi nated if the fresh air damper door is closed the Cir culation LED will be illuminated After start up the fresh air selection is in AUTO the controller will control the fresh air damper door When the key is toggled the damper selection will move to the next step an Auto Closed Open Auto sequence The Auto selection allows controller to operate the damper the Closed or Open being the closed or open damper door selections with the damper door held in those respective positions until the button is toggled again 10 Fan Speed After start up the display obtains the the current fan speed status from the controller Ifthe controller is in AUTO no fan speed LE
89. t s as required h For brush inspection replacement refer to paragraph 4 19 i Re install by performing the above procedure in reverse 4 24 SERVICING THE DRIVER CONTROL BOX The driver control box is located behind the return air panel below the passenger side dash and under the right headlight See Figure 4 10 Remove the return air panel by removing the eight screws holding the panel in place Remove and service the control box by performing the following procedure Q HEADLIGHT DRIVER CONTROL BOX Figure 4 10 Removing Driver Control Box a Turn main battery disconnect switch to OFF position and lock T 312 Remove the power wire from the power stud and the connector from the box Remove the 1 4 inch capscrew at the upper right cover of the box Pull the box laterally approximately 3 4 inch to the right to remove it from the pocket d Rotate box counterclockwise 90 degrees as shown in Figure 4 10 and carefully lift the box out e Repair or replace defective components as necessary Re install the driver control box by reversing the above procedure 4 25 SERVICING THE DRIVER EVAPORATOR 4 25 1 Access Cover Removal Remove stepwell access cover and disconnect 2 inch flex hose adapter Using a flat screwdriver unfasten three 1 4 turn fasteners from access cover on driver evaporator assembly Open driver storage compartment a
90. ted and leave the compressor and second condenser fan energized The second condens er fan remains energized since at least one condenser fan must be en ergized when the compressor is en ergized If this alarm has not been activated three times in 30 minutes it de en ergizes the clutch for the minimum off time and until the alarm is de ac tivated Energizes the second con denser fan at high speed De ener gizes the rest of the system unless heat is required If this alarm has been re activated three times in 30 minutes it de en ergizes the rest of the system The system will operate only in the heat mode until the alarm is reset via communications No microprocessor response other than alarm De energizes all outputs except driv er evaporator fan motor See section 2 1 2 312 Table 3 3 Driver Display Panel Alarm Message Definition Continued TITLE CAUSE REMEDY MICROPROCESSOR RESPONSE A27 Low Pressure Low suction pressure Check cause of low If alarm has been activated three Shutdown suction pressure Re times in 30 minutes the clutch will fer to section 3 3 3 be de energized until the alarm is de activated If alarm has been activated three times in 30 minutes de energizes the rest of the system unless heat is required Runs the main evaporator fan at low speed until alarm is reset A28 High Voltage Power 12 vdc source Check repair or re All microprocessor outputs
91. the valve to open the suction or TO DISCHARGE OR FROM SUCTION LIN ZZ PSS SHES VALVE STEM CAP ZZ CUS S SN VALVE PORT TO STEM COMPRESSOR discharge line to the compressor and close off the gauge connection In normal operation the valve is backseated to allow full flow through the valve The valve should always be backseated when connecting the service manifold gauge lines to the gauge ports Turning the valve stem clockwise all the way forward will frontseat the valve to close off the suction or discharge line to isolate the compressor and open the gauge connection To measure suction or discharge pressure midseat the valve by opening the valve clockwise 1 4 to 1 2 turn With the valve stem midway between frontseated and backseated positions the suction or discharge line is open to both the compressor and the gauge connection 4 1 ACCESS VALVE R 134a Service Valve Backseated counterclockwise ACCESS VALVE CAP Service Valve Frontseated clockwise Figure 4 1 Suction or Discharge Service Valve T 312 4 3 INSTALLING MANIFOLD GAUGES The manifold gauge set can be used to determine system operating pressures add charge equalize or evacuate the system Low Pressure High Pressure Gauge Backseated Hand Valve Frontseated Hand Valve To Low Side Access Valve To High Side Access Valve 3 YELLOW 4 5 Red Knob 6 Blue Knob 1 Manifold Gauge Set Hose
92. til all circuit breakers and start stop switches are turned off and power supply is disconnected Always work in pairs Never work on the equipment alone In case of severe vibration or unusual noise stop the unit and investigate MAINTENANCE PRECAUTIONS Beware of unannounced starting of the evaporator and condenser fans Do not open the condenser fan grille or evaporator access panels before turning the power off and securing the power source Be sure power is turned off before working on motors controllers solenoid valves and electrical control switches Tag circuit breaker and power supply to prevent accidental energizing of circuit Do not bypass any electrical safety devices e g bridging an overload or using any sort of jumper wires Problems with the system should be diagnosed and any necessary repairs performed by qualified service personnel When performing any arc welding on the unit disconnect all wire harness connectors from the modules in the control box Do not remove wire harness from the modules unless you are grounded to the unit frame with a static safe wrist strap In case of electrical fire open circuit switch and extinguish with never use water Safety 1 T312 SPECIFIC WARNINGS AND CAUTIONS WARNING BE SURE TO OBSERVE WARNINGS LISTED IN THE SAFETY SUMMARY IN THE FRONT OF THIS MANUAL BEFORE PERFORMING MAINTENANCE ON THE HVAC SYSTEM WARNING DO NOT USE A NITROGEN CYLINDER WITHOUT A PRESSURE REGU
93. til the proper charge is obtained Backseat suction service valve Close vapor valve on refrigerant drum Replace all valve caps 4 8 CHECKING FOR NONCONDENSIBLES To check for noncondensibles proceed as follows a Stabilize system to equalize pressure between the suction and discharge side of the system The engine needs to be off for several hours b Measure temperature at any of the copper tubing in the condenser Check pressure at the compressor discharge service valve Determine saturation pressure as it corresponds to the condenser temperature using the Temperature Pressure Chart Table 4 6 If gauge reading is psig 2 BAR or higher than the calculated P T pressure in step d noncondensibles are present f Remove refrigerant using a refrigerant recovery system Refer to paragraph 4 6 3 g Evacuate and dehydrate the system Refer to paragraph 4 6 h Charge the unit Refer to paragraph 4 7 4 9 CHECKING AND REPLACING HIGH PRESSURE CUTOUT SWITCH 4 9 1 Replacing High Pressure Switch a The high pressure switch is equipped with schrader valve to allow removal and installation without pumping the unit down b Unplug the wiring from the switch c Check switch operation Refer to paragraph 4 9 2 d Replace switch if it does not function as outlined below Refer to paragraph 4 9 2 4 9 2 Checking High Pressure Switch WARNING DO NOT USE A NITROGEN
94. tive the parcel rack thermal expansion valve and through the driver solenoid valve if this option is active and to the driver thermal expansion valve The solenoid valves open during cooling to allow refrigerant to flow to the thermal expansion valves The main liquid solenoid valve and the parcel rack liquid line solenoid valve when so equipped closes during shutdown to prevent refrigerant migration The thermal expansion valves reduce the pressure and temperature of the liquid and meters the flow of liquid refrigerant to the evaporator to obtain maximum use of the evaporator heat transfer surface The low pressure low temperature liquid that flows into the evaporator tubes is colder than the air that is circulated over the evaporator tubes by the evaporator blower fan Heat transfer is established from the evaporator air flowing over the tubes to the refrigerant flowing inside the tubes The evaporator tubes have aluminum fins to increase heat transfer from the air to the refrigerant therefore the cooler air is circulated to the interior of the coach The transfer of heat from the air to the low temperature liquid refrigerant in the evaporator causes the liquid to vaporize This low temperature low pressure vapor passes through the suction line and returns to the compressor where the cycle repeats When ventilation only is selected by the main controller only the evaporator fans function to circulate air throughout the coach
95. udge formation freezing up of metering devices by free water and formation of acids resulting in metal corrosion 4 6 2 Preparation e NOTE 1 Using a compound gauge for determination of vacuum level is not recommended because of its inherent inaccuracy Never evacuate an open drive compressor below 500 microns T 312 a Evacuate and dehydrate only after pressure leak test Refer to paragraph 4 5 b Essential tools to properly evacuate and dehydrate any system include a good vacuum pump with a minimum of 6 cfm 10 2 3 volume displacement CTD P N 07 001 76 11 and a good digital micron vacuum indicator CTD P N 07 00414 00 Keep the ambient temperature above 60 F 15 6 C to speed evaporation of moisture If ambient temperature is lower than 60 F 15 6 C ice may form before moisture removal is complete It may be necessary to use heater blankets heat lamps or alternate sources of heat to raise system temperature 4 6 3 Procedure for Evacuation and Dehydrating System a Remove refrigerant using a refrigerant recovery system CTD P N MVS 115 F L CT for 115 volt power source or CTD P N MVS 240 F L CT for 240 volt power source b The recommended method is connecting two lines 3 8 OD copper tubing or refrigerant hoses designed for vacuum service to the manifold guage set Attach one line to the condenser service King valve and the other line to the eva
96. ugged wiring defective or discharge pressure transducer failure Sensor is unplugged wiring defective or humidity transducer failure Defective wiring or coach power source de fective microprocessor Internal fuse is blown Main evaporator fan overload Condenser fan over loads Ensure sensor is plugged in Check sensor resistance or wiring Replace sen sor or repair wiring Refer to section 4 13 and Table 4 3 Ensure sensor is plugged in Check transducer voltage or wiring Replace sen sor Or repair wiring Refer to section 4 15 and Table 4 5 Ensure sensor is plugged in Check transducer voltage or wiring Replace sen sor Or repair wiring Refer to section 4 15 and Table 4 5 Ensure sensor is plugged in Check transducer voltage or wiring Replace sen sor or repair wiring Refer to section 4 14 and Table 4 4 Repair or replace wiring or power source Replace Fuse Refer to section 3 3 6 Refer to section 3 3 3 and or 3 3 4 Ignores ambient temperature and does not lock out the compressor and does not open driver RAM air in AUTO mode Energizes unloaders Energizes unloaders If conditions allow not including the humidity set point humidity sensor condition activates humidity control dehumidification See section 2 3 4 Does not open passenger RAM air in AUTO Refer to section 2 3 11 All microprocessor outputs are de energized No microprocessor response
97. ve Components furnished by the coach manufacturer include auxiliary heater and engine water pump auxiliary heater hand valves and Y type strainers The main controller automatically controls the EHV valves during heating and reheat cycles to maintain required temperatures inside the coach Engine coolant glycol solution is circulated through the heating circuit by the engine and auxiliary water pumps When the evaporator heat valve solenoid is de energized the valve will open to allow engine coolant to flow through the heater coil See Figure 1 11 The valve is normally open so thatifa failure occurs the system will still be able to supply heat AIR BLEED il VALVE DRIVER HEATER CORE HEAT VALVE MAIN HEATER CORE HAND VALVE H DRAIN VALVE STRAINER HAND VALVE AUXILIARY HEATER BYPASS HEAT VALVE ENGINE WATER PUMP o ENGINE INDICATES COMPONENTS FURNISHED BY THE COACH MANUFACTURER Figure 1 11 Heating System Flow Diagram T 312 1 8 AIR CONDITIONING REFRIGERANT CYCLE When air conditioning cooling is selected by the main controller the unit operates as a vapor compress
98. y Expansion Board Main Controller Packard Connector Pins L thru Y Packard Connector Pins A thru K Coach Interface Connector Model Serial Number Plate Box Model Serial Number Tag Controller Figure 1 7 Main Control Box 3 T 312 Displa Defrost Driver s shay Evap Blower Up Increase Selection Down Decrease Selection Automatic Control Cooling Vent Only Only DEF E EN 27 Heat Driver s Evap Coolant Valve On Off Fresh Air Inside Outside Temperature Heat Only Fan Speed Figure 1 8 System Operating Controls upper left hand switch panel 1 2 5 System Operating Controls And Components There are five controls on the driver s station which affect the operation of the Carrier supplied equipment covered by this manual These controls include two rocker switches two slide switches and the Micromate Control Panel The first slide switch is the Defrost Switch Figure 1 8 This switch controls the driver evaporator blower motor speed The second slide switch is the Heat Switch Figure 1 8 This switch controls the driver evaporator coolant valve These switches are located on the dashboard to the left of the steering wheel The third control is the Driver Display Panel Figure 1 8 which operates the Carrier Transicold micro
99. y foreign material from the valve body valve seat and mating surfaces Do not adjust the new replacement expansion valve Valves are preset at the factory Using new gaskets install new cage and power head assemblies provided with repair kit The thermal bulb is installed below the center of the suction line four or eight o clock position This area must be clean to ensure positive bulb contact Strap thermal bulb to suction line and insulate both with Presstite Ensure that retaining straps are tight See Figure 4 7 Connect equalizer line to the expansion valve j Evacuate and dehydrate Refer to paragraph 4 6 Open filter drier inlet valve liquid line service valve and all service valves Run the coach for approximately 30 minutes on fast idle m Check refrigerant charge Refer to paragraph 4 7 1 n Check superheat Refer to paragraph 4 11 2 2 Suction Line end view TXV Bulb Clamp Nut and Bolt clamp Thermocouple TXV Bulb Shown in the four o clock position Figure 4 7 Thermostatic Expansion Valve Bulb and Thermocouple Installation 4 11 2 To Check Measure Superheat NOTE All readings must be taken from the leaving side of the evaporator a Open filter access door b Remove Presstite insulation from expansion valve bulb and suction line c Loosen one TXV bulb clamp and make sure area under clamp above TXV bulb is clean
100. zed if required Any subsequent changes between energizing and de energizing the unloader solenoids must be staged with a thirty second delay Only one unloader may change state at a time when staging is required a Suction Pressure In addition to temperature control the electric unloaders will be used to prevent coil frosting Staging is ignored for energizing the unloader solenoid due to suction pressure overrides 1 Compressor Unloader Bank 1 Solenoid UV1 When the suction pressure decreases below 25 psig 1 7 BAR the first unloader solenoid is energized unloading the first compressor cylinder bank two 2 5 cylinders this output will remain energized until the pressure increases to above 32 psig 2 18 BAR Compressor Unloader Bank 2 Solenoid UV2 When the suction pressure decreases below 21 psig 1 43 BAR the second unloader solenoid is ener gized unloading the second compressor cylinder bank two cylinders this output will remain ener gized until the pressure increases to above 28 psig 1 91 BAR b Discharge Pressure Head Pressure is also controlled by the unloaders Staging is ignored for energizing the unloader solenoid due to discharge pressure overrides 1 Compressor Unloader Bank 1 Solenoid UV1 When the discharge pressure increases above 340 psig 23 13 BAR the first compressor unloader so lenoid is energized this output will remain energized until the pressure decreases below

68g5-105 series mci j4500 coach - North America Transport Air

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