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OPERATION AND SERVICE MANUAL - Omega

1. BOLT SIZE Grade 2 not for Grade 5 GRADE 8 Thread Pitch compressor mounting Aluminum Cast Iron Aluminum Cast 1 4 20 UNC 6 7 9 11 5 16 18 UNC 12 15 18 22 3 8 16 UNC 20 30 34 40 7 16 14UNC 35 45 50 58 7 16 20 UNF 40 50 55 65 1 2 13 UNC 55 70 70 92 1 2 20 UNF 60 75 95 110 5 8 11 UNC 110 135 150 190 5 8 18 UNF 120 155 170 215 METRIC BOLTS TORQUE IN FOOT LBS BOLT SIZE Grade 8 8 Grade 10 9 Grade 12 9 Aluminum Cast Aluminum Cast Aluminum Cast M6 x 1 0 5 7 8 9 8 9 M8 x 1 25 13 18 18 23 21 27 M10 x 1 5 22 30 35 45 40 50 M12 x 1 75 40 55 60 75 75 95 M14 x 2 0 65 85 95 120 110 145 M16 x 2 0 110 130 135 175 165 210 TORQUE SPECIFICATIONS REFRIGERANT FITTINGS always use longer backup wrench Fitting Threads Tubing O D FLARE Fitting O RING Fitting Torque ft Ib Size Hose I D Torque ft lb Aluminum Steel 4 7 16 20 1 4 10 15 5 7 5 10 6 5 8 18 3 8 5 16 20 25 10 13 10 15 8 3 4 16 1 2 13 32 35 40 15 20 15 22 10 718 14 5 8 1 2 50 60 21 27 22 30 12 1 1 16 12 3 4 5 8 70 80 28 33 28 36 Switches na 5 10 5 7 5 10 Page 16 COMPRESSOR DRIVE BELT MAINTENANCE There are several factors that have major effects on compressor drive belts life expectancy and reliability Belt alignment and proper tens
2. See Box Below and previous diagram for Three Evaporator Unit Install BUTT SPLICE 8 Battery 100 Amp BDS k Note This End TO RD ofHamess Aa vem Cut to Desired MATCH OW tengih COLORS IGN POWER RD h P 10 Amp i ar ie ATC Fus TM TOUCHPAD CONTROLS K Ve 3669 ATA EN E z NOTE I Mn The controls Compressor und negative Clutch switching Coil BUTT SPLICE 13 EI Eso 4 BR MATCH RD J COLORS AS Relay Harness EUM BR or I M p n33 1 3642 2 TOUCHPAD CON FRORES KIT 13669 Condenser Fan Motors M gt d d 4 Main Harness p n33 72156 For Three Evaps Add amp B D Solenoid Harness p n33 72156 For Tie IN Evaporator Unit Use Two Control Kits As Provided First EF1 amp CS1 will draw approx 38 Amps second will add approx 22 Amps Total 60 First EF3 amp CS1 will draw approx 55 Amps second EF3 will add approx 34 Amps Total 89 Rapid Start of first system alone to High Will Cause Spike of 65 Amps Approx Actual Results Will Depend on Bus Alternator and Voltage Regulator Ability to Sustain Voltage RFVISION 2004 Page 32 BY MODEL ILLUSTRATED PARTS LIST Single Dual Blower 22 x 44 MODEL EF1 1 1 1C 1D 2 3 3 opt 3 opt 4A 6
3. CS2 SKIRTMTG 2280 18 2 AMPS TWO 14 FANS 4Row COND NLA CS3 SKIRTMTG 2950 18 5 AMPS THREE 11 HD 6Row COND NLA NOTE ABOVE MODEL MAY BE STACKED TWO HIGH CS4 SKIRT MTG 1930 CFM 12 AMPS THREE 9 FANS 4Row COND NLA CS5 SKIRTMTG 2950 26 THREE 11 6Row COND 24 41531 CS6 SKIRTMTG 2950 26 THREE 11 4Row Sub Cool NOTE ABOVE MODEL MAY TWO HIGH Page 7 OPERATION See Operation Safety at front of manual NORMAL OPERATING INSTRUCTIONS The system may have either a rotary knob blower switch and push button A C switch or a touch pad membrane control The control is always located within reach of the driver area With either control package the operation is straight forward Engine must be running for A C system to operate Operators should be encouraged to follow the simple guidelines that follow 1 avoid needless voltage current draw spikes on the vehicle voltage regulator and battery charging system check that the cooling system blower is OFF PRIOR TO STARTING ENGINE 2 The blower switch or pad area should be set to LOW FIRST THEN FIVE TO TEN SECONDS LATER GENTLY PUSH ON THE A C BUTTON Then as desired to each higher speed similarly pausing between each speed 3 Turning the unit off should follow the reverse procedure OPERATOR SHOULD FULLY TURN OFF UNIT PRIOR TO TURNING OFF ENGINE PUSHING THE A C BUTTON IN A SECOND TIME TO DISE
4. LOW THEN A C BUTTON FOR FANS MEDIUM amp FINALLY HIGH Total RUN 72 Amps Body Disconnect Solenoid Normally Supplied By or Installer OMEGA p n 30 13416 100Amp 4 Post may be ordered separately OR Power Relay hit 36 00028 75 Amp Relay ONE PER EVAPORATOR UNIT See Box Below and previous diagram for Three Evaporator Unit Install so on board 72 40 112 Amps E Pin 33 26901 REVISION C JUNE 2007 Approx Actual Results Will Depend on Bus Alternator and Voltage Regulator Ability to Sustain Voltage Page 30 OLDER UNITS Included for Service Reference ELECTRICAL WIRING DIAGRAM MODELS EF1 EF2 amp EF3 Body Disconnect Solenoid Normally Supplied By OEM or Installer OMEGA p n 30 13416 100Amp 4 Post may be ordered separately ROTARY KNOB PUSH BUTTON CONTROLS C B BDS BUTT P N 33 50018 Complete Assy w Panel SS 22 SPLICE BL go Sopan s R F So SPUR orHamess MATCH 1 gt el ow Cutto Desired p c Swit Y 10 Amp Length COLORS Er E Blower Switch ALT 4 ATC Fuse Inam Note L ta H OFF O H The controls are RDA im Compressor m i gun pate pmas ti005 Clutch si Coil OR 42V Main endo TOUCHPAD CONTROLS KIT PINS redeo Pu P N
5. p A Note This End RET 70 100 ss 40 1 Blower Y OEM or INSTALLER 1 Desire Switch iv High Capa PRIM ag 33 20005 Lang i BC pin2 21901 Blower Alternator SENE A NOTE f 11 Note L to OFF 9 RD EET T me VIR 110 Amp n361337 switching i ATC Fuse CSWkh BK FONS Main Harness TOUCHPAD CONTROLS KIT P N 33 13669 rower 33 13710 i 1 4 Relay p n33 13714 IGN pen C B 642v B V 20 Amp Dum 33 g0003 High Side Evaporatori _ Ramis es A I AU Dual Pressure Blower 5 EF2 i CS1 amp CS2 S VL wu Motor s l yox 2 afety Switch MEET 1 A ES I T p n 29 20901 Qe i BL 1 d Condenser TM pe i art 53 4 5 8 CS6 Fan Motors H gt 1 TIA Li f i 1 I 1 i n 15 Amp BLAW ATC EF1 Fuses Empty H3 i Empty H2 2 COl 15 T 4 Somon 7 5Amp L a Res e s 87 Normaly Open or p n33131907 87 Normaly Closed EF2 Fuses 2 84 40Amp Rated Empty H3 E SPDT wlResistor 20 Amp H2 RDI ta a Suppression 20 Amp H1 S Relayp n30 13412 25 Bb r3 wiResistor 15 L 7 l WIRE COLOR CODE TPA d ER i
6. Fix any leak that can be identified Page 19 1 OMEGA highly recommends UV dye all A C systems Use UV protective enhancement eye ware and thoroughly examine entire system with UV light 2 Soap and or radiant dye solutions may be sprayed brushed or poured on specific locations like end fittings In certain cases like a large leak electronic leak detectors will not function correctly and thus solution testing may be necessary 3 Electronic leak detectors are often convenient for checking the general area of a coil as well as end fittings Proper usage requires slow and deliberate motion Refrigerants are heavier than air and will tend to collect in the bottom of the drain pan if not disturbed by surrounding air movement Follow instructions provide by equipment manufacture If no leaks can be found and the system was diagnosed to need adjustment and if the amount finally added is less than half a pound then dye should be added and the unit should be rechecked in the next quarterly If a pound or more is added later see Charge Determination then dye should be added and the system should be leak check again after thirty minutes to one hour of run time REFRIGERANT LEAK CHECK SYSTEM WITHOUT PRESSURE If the system had dye then the UV light method is straight forward A system without dye should also be entirely looked over first with a bright light If any thing obvious or highly suspicious is found then repair it prior further pressur
7. install replacement Check operation especial correct direction of rotation of blower motor Permanent magnet D C motors will reverse if positive and negative wires are exchanged air delivery will be low CONDENSER FAN ASSEMBL Y s Disconnect battery ground cable If one fan motor has worn out to the point of failure please consider replacing them both so as to avoid other damage due to high pressure in the near future Check operation especial correct direction of rotation of fan motor Permanent magnet D C motors will reverse if positive and negative wires are exchanged do not rely on wire colors alone REFRIGERATION SERVICE PROCEDURES FOLLOW ALL SAFETY AND OPERATIONAL PRECAUTIONS WARNING THE UNIT MAY CYCLE ON THE FANS AND COMPRESSOR UNEXPECTEDLY AS CONTROL REQUIREMENTS DICTATE BEWARE OF UNANNOUNCED STARTING REMOVE POWER PRIOR TO TOUCHING COMPONENTS THAT NORMALLY MOVE WARNING NEVER USE SHOP AIR FOR LEAK TESTING IT HAS BEEN DETERMINED THAT PRESSURIZED REFRIGERANT AND AIR RICH MIXTURES CAN BE COMBUSTIBLE WHEN EXPOSED TO AN IGNITION SOURCE ALWAYS USE MINERAL OIL TO LUBRICATE O RINGS AND FITTING THREADS PAG OIL IN THE SYSTEM WILL ABSORB MOISTURE AND BECOME VERY ACIDIC AND CORROSIVE DO NOT USE IT ON EXTERNAL PARTS USING ONLY THE COMPOUND GAUGE OF THE SERVICE SET FOR DETERMINATION OF VACUUM LEVEL IS NOT RECOMMENDED BECAUSE OF ITS INHERENT INACCURACY VACUUM PUMPS REQUIRE ROUTINE OIL CHANGE TO MAINTAIN FULL PUMP DOWN
8. 10 12 hours of run time a belt will stretch more then the rest of its service life It is important therefore to re tension per guidelines below DRIVE BELT TENSION GUIDELINES Check the tension when the belt is hot from running If it is below the threshold value then allow it to cool and adjust to re tension value If installing a new belt start with that value with belt cold DRIVE Re Tension If Re Tension New Belt Initial Below Threshold Run In Belt To Tension Lbs Compressor A grove 80 105 130 Alternator A grove 70 90 110 Poly Rib Belt 6 Ribs 90 110 145 amp Serpentine or More Poly Rib Belt amp Serpentine With Spring Tensioner NON ADJUSTABLE Please follow belt manufacture guidelines regarding gauge selection operation calibration and any specification that may contradict above values RETURN AIR FILTER RELAY BANK and THERMOSTAT SERVICE SPECIFIC CAUTION Do not allow oils to drip into or on plastic drain pan or any plastic part of these systems as material will absorb and become brittle and prone to crack Follow maintenance schedule or clean as required Series Model EF1 EF2 amp EF3 the main cover must be removed Model EF3 remove smaller end louvers first Relay bank is now accessible Remove four screws and allow drain pan to hang down clean as required Thermostat is now accessible for service if needed Rotate filter end catches and slip filter frame down and out U
9. 205 220 250 102 210 225 104 215 230 106 220 235 109 230 245 300 112 240 255 115 250 118 265 120 275 360 124 290 128 305 Page 23 132 320 360 High pressure switch cut out range 28 kg cm3 10 400psig 40 440 ADJUSTING REFRIGERANT CHARGE Note If using a charging station routinely calibrate it per manufactures instructions Overcharging is to be avoided if at all possible If it has occurred it is likely on a system that is now operating in a much hotter ambient then when the system was initially charged It is also possible that a mistake was made or equipment malfunctioned not calibrated is really an operator problem not a malfunction of the equipment per say Many charging stations use a strain gage weight scale that requires calibration any time they are moved especially if a nearly full cylinder is sitting on the weight platform A bump or jolt from rolling over a floor seam or electric cord is often enough to affect the machine calibration Following all proper steps covered in previous sections Adjusting charge is simply either adding or removing refrigerant from system utilizing gauge set Adding is normally done with system running and will typically be adding charge to obtain best evaporator performance while keeping head pressure in acceptable range Refrigerant vapor is added through low side You may turn the supply cylinder over valve up for vapor or mor
10. 33 13669 BR ES SI RD BL i 5 8 g taf Relay Harness P 2 5 f p n33 13642 M Condensers Fan Motors i E uo c Evaporator Lm ae AT BL Cr Blower 1 Bn re Motor s A0A mp p EF3 7 Ml Jo As U En i sa 654 CS5 i Thermostat RD VT p n32 20901 C B Circuit Breaker 20 133 20003 Dual Binary 1 30Amp p n33 20004 Pressure i 40Amp p n33 20005 Switch i Relay Key b 029 301 Dual i 85 amp 86 Coil Pressure EN V 30 Common Switch A 1 ul 1 87 Normaly Open NOTE wiResistor 87A Normaly Closed OR H i k 300K 4 lt T 1 Relay Hamess S COLOR CODE l resistors BK Black P n33 13683 paio BL Blue S k motors i BR Brown RB ALT i GY Gray Are t Sutin YL 1 T 4 1 I YL Yellow e RET WT White 40Amp Rated Speed Resister s SPDT w Resistor p n 33 31907 Suppression Rewire Is Possible To Up RFVISIONA JAN 2004 Speeds amp Current Draw of LEM ORto1 RDto2 YLto3 Relay p n30 13412 OLDER UNITS included for service reference SECOND UNIT TIE IN WIIH ONE COMPRESSOR ELECTRICAL WIRING DIAGRAM MODELS EF1 EF2 amp EF3 Body Disconnect Solenoid Normally Supplied By OEM or Installer OMEGA p n 30 13416 100Amp 4 Post may be ordered separately
11. 6 This is the system total calculated amount of new oil required If also replacing compressor Note that a new compressor has oil in it and thus subtract charge from the total calculated and this is the final add amount As you can clearly see this could really be a complicated situation and would require close attention to all the math in the above calculations So the simplified recommendation for typical bus installation is to add back all the recovered oil plus amount s listed below for each component that is being replaced Hose s 6 0 05oz per ft 8 0 063oz ft 10 0 078oz ft 12 0 11oz ft Model EF1 EF2 EF3 Evaporator coil 1 5 oz 45cc Model EF4 Evaporator coil 1 1 oz 33cc Model CS1 Condenser 2 0 oz 60cc Model CS2 Condenser 3 5 oz 100cc Model CS3 amp CS5 Condenser 2 5 oz 75cc Model CS4 amp CS6 Condenser 1 75 oz 50cc Receiver Drier 0 5 oz 15cc 0 5 oz 15 cc Recovered amount TOTAL Total amount to be poured into compressor suction port not the component Disconnect the suction fitting at the compressor add calculated amount of oil back to system by hand turn the compressor clutch drive plate at least ten times to distribute oil inside Page 26 compressor and assure that it is not overfilled Install new o ring and reconnect suction fitting Again turn compressor by hand to assure oil distribution Remove and replace receiver drier replacing all o rings Iubricated with mineral oi
12. 7 8 9 10 11 12 13 MODEL EF1 EVAPORATOR ONE DUAL BLOWER P N 27 19503 40 32429 40 32423 40 32436 40 42910 31 30902 31 30927 31 30957 40 40123 40 32502 28 41400 40 41520 28 94107 28 41520 40 43053 26 19912 40 42840 A DESCRIPTION QTY EVAPORATOR COIL 1 VOLARA TAPE 1 8 X 2 6 85 FT FOAM TAPE 1 2 X 3 4 1 5 FT TAPE VOLARA 1 8 X 1 2 1 2 FT TOP TRAY FOR BUS UNIT 1 EXP VALVE BLOCK 2 1 2 TON EF2 or EF3 single 1 EXP VLV BLOCK 2 TON EF1 single EF2 or EF3 tee in EXP VLV BLOCK 1 1 2 EF1 tee in BRACKET RELAY MOUNTING 1 Electrical Components Are On Wiring Diagram AIR FILTER ASSY 1 DRAIN PAN ASSY W BRKTS FOAM COVER amp 1 PORTS FRESH AIR RETURN GRILL METAL EURO LOUVER 3 82 X 10 11 SHROUD MAIN COVER 3 LOUVER BRACKET BLOWER SUPPORT BLOWER DUAL SCROLL 12V Complete Assy WALL FOR SINGLE MOUNT MOTOR Aw 4 19 05 10 10 07 Page 34 Two Dual Blowers 22 MODEL MODEL EF2 TWO DUAL BLWRS ITEM 1 1 1C 1D 2 3 3 opt 3 opt P N 27 19503 40 32429 40 32423 40 32436 40 42910 31 30902 31 30927 31 30957 40 40123 40 32502 28 41400 40 41520 28 94107 28 41520 40 43053 26 19912 40 42911 DESCRIPTION EVAPORATOR COIL VOLARA TAPE 1 8 X 2 FOAM TAPE 1 2 X 3 4 TAPE VOLARA 1 8 X 1 2 TOP TRAY FOR BUS UNIT EXP VALVE BLOCK 2 1 2 TON EXP VLV BLOCK 2 TON EF1 single EF2 or EF3 tee
13. 8 x 8 W PORT 7 16 20 flare w schrader SPLICER Straight 10 x 10 W PORT 7 16 20 flare w schrader TEE SPLICER 8 X 8 X 8 hose TEE SPLICER 12 X 12 X 12 hose Ftg 45 8 FOR LPX 10 W R134A Charge Port 16mm Ftg 45 10 FOR LPX 12 With R134 Charge Port 13mm HOSES HOSE 8 13 32 ID HOSE 10 1 2 ID HOSE 12 5 8 ID Clamp Hose Routing 2 3 8 Clamp Double Hose Rubber Lined PRESSURE SWITCH SWITCH DUAL PRESSURE SAFETY ON 28 PSI OFF AT 400 PSI OPTIONAL HARDLINES HARDLINE SET LONG HARDLINE SET SHORT E Z CLIP TOOL KIT E Z CLIP Kit W Tools amp Accessories Page 46 TYPICAL LOCATION USAGE COMPRESSOR Discharge High Side Service COMPRESSOR SUCTION Low Side Service Condenser INLET Condenser OUTLET ON DRIER COND Out On Drier Port for Press SW TXV IN Used With Hardline TXV IN w o Hardline Option TXV OUT Used With Optional Hardlines TXV OUT w o Hardline Opt HIGH SIDE Has Port for Pressure Switch Optional Location High Side W SW Port LIQUID LINE TEE IN SLAVE Evaporator SUCTION LINE TEE IN SLAVE Evaporator Option Comp or Cond High Side Service Option Comp Low Side Service LIQUID LINE Discharge SUCTION Hose Routing Hose Routing Port Either On Drier Ftg Or Liquid Splicer Evap Between TXV and Hose Ftgs Early Models Evap Between TXV and Hose Ftgs Early Models reserves the right to deny warranty coverage claims due to la
14. CAPABILITIES A TWO STAGE VACUUM PUMP IS REQUIRED TO ACHIEVE VACUUM IN THE 1000 MICRON AND BELOW RANGE WEAR EYE PROTECTION AND GLOVES ANY TIME REFRIGERANT HANDLING IS INVOLVED Page 18 PLEASE READ ALL SECTIONS THAT FOLLOW FOR TIPS AND INSIGHT THIS MANUAL IS NOT A FULL SUBSTITUTE FOR INITIAL TRAINING IN A C SYSTEM DIAGNOSIS OR REFRIGERANT HANDLING PREPARING MANIFOLD GAUGE SET FOR USE If the manifold gauge set is new or was open to atmosphere then it will require evacuation to remove air to avoid contamination of system Close both high and low side end couplings Open both the high side and low side manifold valves Connect the gauge set to the vacuum pump and fully evacuate Assuming the gauge set will next be connected to a charged system for service or annual maintenance check then next connect the service line with self sealing end fitting to refrigerant supply cylinder Slowly open cylinder valve to allow vapor only into the gauge set until the low side pressure is 40 to 60 psi close cylinder valve Close both manifold valves and the set is now ready to connect to a charged system With a four hose manifold set the procedure is nearly the same except the cylinder and vacuum pump will both be connected and all hoses will be evacuated close the valve to the vacuum pump and then refrigerant vapor charge the other three hoses MANIFOLD GAUGE SET USAGE The manifold set is used to connect to system and thus determine system operating pr
15. DATE Sign Monthly Name DATE Sign Quartery Name DATE Sign ETC Page 47
16. T at first gets rapidly better with each add but then improves only slightly as correct charge is approached the same time the high side pressures don t change much first but began to increase in larger steps When the initial charge is about right and little delta T change is observed with first add and high side is close to chart value then the system is ready If the high side jumps up and is now 30 to 40 psi above the chart value then even if the evaporator performance got slightly better then for sure it s time to stop adding refrigerant shut off system and recover last increment added The proceeding is for system service when exact amount of refrigerant in system is not known If the system were being fully recharged after service then the data plate riveted under the hood Page 22 should be stamped with charge weight In this case charge to that amount and verify high side value from chart Typical charge weight will be about 5 2 Ibs for EF1 2 or 3 Evaporator with CS1 systems and 6 5 Ibs is typical for systems with CS6 and second slave unit OPTIMUM CHARGE DETERMINATION WORKSHEET R134a CAUTION DO NOT CONTINUE TO OPERATE SYSTEM WITH LOW SIDE PRESSURE LESS THAN 10 PSI begin with enough refrigerant to prevent compressor damage Compressor Engine RPM at 3 4 max road speed RPM Evaporator main cover on and louvers all open Open windows for max heat load and attempt to maintain steady state entering air temperatures Check cal
17. dust all over it Discussion A clutch requires at least 12 volts to operate and work best with full voltage of alternator The supply voltage should be checked maybe the coil is internally shorting thus less inductive load more current draw and thus lowering voltage Maybe the clutch relay was not installed and thus the current has to travel the entire length of the wire from the thermostat this wire is sized for control circuit and the long length will result in excessive voltage drop when conducting clutch current Maybe the clutch relay contacts have corroded which causes resistance and lowered the voltage Solution All the items mentioned in the discussion are checked which ever electrical problem s that are found are corrected The mechanical part of the clutch is cleaned up the air gap is checked the engagement surfaces are examined It may be determined that the clutch is fine or that a new clutch is also installed either way the root cause of the problem is found rather than just replacing the malfunctioning component Knowledge of basics experience and full fledged trouble shooting is what it takes to keep systems operating correctly ABNORMAL COMPRESSOR NOISE WHEN CLUTCH IS NOT ENGAGED POSSIBLE CAUSE ACTION REMEDY Drive belt Check tension and inspect Adjust or replace belt Strobe light check belt bounce and clearances Faulty clutch bearing Remove drive belt turn clutch by hand Remove clutch bearing or Listen and feel for
18. in EXP VLV BLOCK 1 1 2 TON EF1 tee in BRACKET RELAY MOUNTING Electrical Components Are On Wiring Diagram AIR FILTER ASSY ASSY DRAIN PAN W BRKTS FOAM COVER amp PORTS FRESH AIR RETURN GRILL METAL EURO LOUVER 3 82 X 10 11 SHROUD MAIN COVER 3 LOUVER BRACKET BLOWER SUPPORT BLOWER DUAL SCROLL 12V Complete Assy WALL DUAL BLOWER MOUNTING 4 19 05 10 10 07 Page 36 QTY 6 85 FT 1 5 1 2 gt N N WO Drivers Pack Uwe semel Blowers ame Dual Center Blower 22 x lt ai MODEL EF3 C 006066 MODEL EF3 EVAPORATOR DUAL WITH DRIVERS PKG ITEM P N DESCRIPTION QTY REQ D 1 27 19503 EVAPORATOR COIL 1 1B 40 32429 VOLARA TAPE 1 8 X2 6 85 FT 1C 40 32423 FOAM TAPE 1 2 X 3 4 1 5 FT 1D 40 32436 TAPE VOLARA 1 8 X 1 2 1 2 FT 2 40 42910 TRAY FOR BUS UNIT 1 3 31 30902 EXP VALVE BLOCK 2 1 2 TON 1 3 opt 31 30927 EXP VLV BLOCK 2 TON EF1 single EF2 or EF3 tee in 3 opt 31 30957 EXP VLV BLOCK 1 1 2 TON EF1 tee 4 40 40123 BRACKET RELAY MOUNTING Electrical Components Are On Wiring Diagram Replaced by 40 40124 with key slot for wires and 40 40125 w o key slot 40 40126 Brkt with studs for Blwr Mtg 4 19 05 10 10 07 1 1 6 40 32502 AIR FILTER ASSY 1 7 28 41400 ASSY DRAIN PAN W BRKTS FOAM COVER 8 PORTS 1 8 40 41520 FRESH AIR RETURN GRILL METAL 3 9 28 94107 EURO LOUVER 3 82 x 10 11 2 10 28 94110 EURO LOUVER 3 82 x 5 64 1 11 28 4152
19. the basic principals are not covered in this manual What is provided is clear and concise wiring diagram s for the systems we manufacture We use ground switching exclusively for controlling relays for blower speeds because of the inherent safety in avoiding shorts in the control circuits and to minimize voltage drop in long run feed wires Using this technique also relieves the blower switch from having to carry high blower current and thus only milli amps pass through the switch to control the relays does provide installation training and strict guidelines for installation of systems However systems are installed in an after market forum and installation centers are responsible for the many details involved in each application You may find subtle differences in small things like pressure switch location or hose and wiring routing etc We offer the following tips A simple test light may be used for ground switching diagnostics in some cases by putting the clamp lead to a known positive battery source However the test light approach may fall short if voltage drop due to current load or corrosion is the issue Good grounding is just as important as supply voltage as it completes the circuit We strongly recommend that each system be thoroughly checked when new Make note of install particular voltage drops and current draws Our tip is to use a black marker and simply write the numbers on the major component on the metal inside the evaporato
20. 1 p n33 13714 4 2 CB BL wt 4 20 Amp nan q MK 20003 BUN BL aay ai Main Hamess p n33 13710 Ee n _ T fi M Hi I j lt e 15 Amp i A I ATC Fus 5 CS34 58 CS34 5 8 CSE gt BDS Ne 100 TAI a nos w 9133107 LI TEN POWER XO finer I R OR ehh TN CB BD p 3 EG T 1i P IGN POWER E ET gt TRU IR For Three Evaporators ie Second System Add Circuit Breaker amp B D Solenoid or Power 33 20901 S Main Harness For Tie IN Evaporator Unit Use Two Control Kits As Provided p n33 13710 22 MY TT 1 First EF2 22 amp 1 18 will draw approx 40 i T3 L Vi l add a second EF2 will add approx 22 Amps Total RUN 62 Amps First EF3 34 amp Cs6 26 will draw approx 60 Amps add a EF1 14 will add approx 14 Amps On same bus 72 pass if EF2 amp CS1 Second System al At start of any system at High Will Cause Massive 6X Spike of IN RUSH Amps While motors are beginning to spin the current rapidly falls off however even with a clamp meter you can observe the spike as double or tripple depending on the meter used Encourage ONE AT A TIME RAMP UP TURN ON OF A C UNITS
21. 6 SHROUD MAIN COVER 5 LOUVER 1 12 40 43053 BRACKET BLOWER SUPPORT 1 13 26 19912 BLOWER DUAL SCROLL 12V Complete Assy 1 14 26 19953 BLOWER SINGLE SCROLL 12V Complete Assy 2 15 40 42840 A WALL FOR SINGLE MOUNT MOTOR 1 16 40 42858 BRKT AUX MOTOR BUS DVRS PKG 2 1 1 4 Page 38 INSTALLATION ACCESSORIES COVER PARTS Black Galvanized White plastic plastic steel SIDE MOUNTED REAR MOUNTED EVAPORATOR EVAPORATOR Page 39 INSTALLATION 1 1 1B 1C 1D 1 2 NS 3 P N 28 41521 part of set part of set part of set part of set part of set part of set 28 51524 28 71713 40 42836 DESCRIPTION HOSE COVER SET 6 WHITE PIECES COVER EVAP ADAPTER COVER RIGHT 45 DEG ADAPTER COVER LEFT 45 DEG ADAPTER COVER LEFT DIR CHANNEL COVER RIGHT DIR CHANNEL COVER STRAIGHT 40 X 4 X 2 5 COVER FLOOR BOOT BLACK FLOOR GROMMET 3 PLASTIC SUPPORT BRACKET FOR BUS HOSE COVER SIDE MOUNTED EVAPORATOR Front Bracket Components AISLE 4 5 6 not shown 7 8 not shown not shown not shown 9 10 not shown not shown not shown 40 42827 40 42814 40 62839 40 62845 40 42851 40 42813 40 62813 40 62849 40 62850 K 40 67057 40 42909 40 67058 40 67036 40 67037 BRKT FREEBLOW SIDE WALL FRONT BRACKET RAIL LINK B CLEVIS PIN 5 16 X 1 875 COTTER KEY 079 DIA W CLEVIS PIN 40 62839 BOLT CARRIAGE 5 16 18 X 6 BRAC
22. 60004 9 25 11122 10 40 40026 11 40 40030 12 40 40004 13 40 40084 notshown 40 40029 A not shown 40 40043 MODEL CS3 CONDENSER 3 FAN 11 DESCRIPTION COIL THREE FAN CONDENSER VOLARA 1 8 X 2 ADHESIVE 50 PER ROLL TUBE CONDENSER INLET All Electrical Components On Wiring Diagram BRACKET MOUNTING CONDENSER DRIER BRKT M FOR 24 30105 END PLATE CONDENSER DRIER INLINE FILTER w o Sight Glass TUBE OUTLET TO DRIER FAN 11 HIGH PROFILE PULLER FAN GUARD THREE FAN CONDENSER SHROUD FAN CONDENSER SUPPORT CONDENSER METAL GRILLE ASSY BUS CONDENSER WITH OMEGA LOGO END PLATE CONDENSER BRACKET CONDENSER LINE Page 43 YO WW n MODEL CS5 amp C86 CONDENSER 3FAN 11 Internal Configuration Fans Inside Cover ITEM CS5 1 CS6 P N 24 41525 24 41530 40 32429 40 40117 40 42830 37 10860 33 13697 35 60056 25 11131 40 40081 40 40118 40 40119 40 40004 35 60056 35 60061 40 40084 40 40120 DESCRIPTION COIL 6 ROW 4 CIRCUIT COIL 10 X41X4 ROW SINE WAVE 3 TO 1 SUB COOL VOLARA TAPE 1 8 X 2 ADHESIVE 50 PER ROLL END PLATE CONDENSER DRIER BRKT M FOR 24 30105 DRIER INLINE FILTER w o Sight Glass HARNESS WP THREE FUSE FUSE 15 AMP ATC TUBE CONDENSER OUTLET TO DRIER FAN 11 HIGH PROFILE PULLER MP FAN GUARD THREE FAN CONDENSER END PLATE CONDENSER SHROUD FAN CONDENSER STRAP SUPPORT COND TUBE CONDENSER INLET T
23. IGERATION SERVICE PROCEDURES 18 PREPARING MANIFOLD GAUGE SET 19 MANIFOLD GAUGE SET USAGE 19 REFRIGERANT LEAK CHECK SYSTEM WITH PRESSURE 19 REFRIGERANT LEAK CHECK SYSTEM WITH OUT PRESSURE 20 EVACUATION AND DEHYDRATION 20 RECOVERY NOTES 21 ADDING REFRIGERANT FULL CHARGE 21 OPTIMUM CHARGE DETERMINATION 22 CHARGE DETERMINATION WORK SHEET 23 ADJUSTING REFRIGERANT CHARGE 24 COMPRESSOR REPLACEMENT 24 ADDING OIL WHEN COMPONENT IS REPLACED 25 COMPRESSOR OEM OIL AMOUNTS LIST 27 REPLACING RECEIVER DRIER 27 REPLACING HIGH PRESSURE SWITCH 27 REPLACING TXV BLOCK VALVE 27 WIRING DIAGRAMS 28 32 ILLUSTRATED PARTS LIST 33 46 Page 3 GENERAL NOTICES The following general safety notices supplement the specific warnings and cautions appearing elsewhere in this manual The recommended precautions cautions and warnings must be understood and applied during operation service and maintenance of the equipment covered herein FIRST AID An injury no matter how slight should never go unattended Refrigerants can cause damage to skin and eyes Always obtain first aid or medical attention immediately in the event of an accident OPERATING SAFETY PRECAUTIONS Keep hands clothing and objects clear of any moving components including evaporator blowers condenser fans and compressor drive belts and pulleys Beware of unannounced starting of evaporator blowers condenser fans or compressor clutch engagement In case of severe v
24. KET RAIL LINK A FLAT WASHER 10mm WASHER FLAT 5 16 FLAT SAE NUT KEPS 5 16 18 Hex Rear Bracket Components SIDE BOLT CARRIAGE 3 8 16 X 1 1 2 BRKT RAIL FREEBLOW SIDE MNT REAR FLAT WASHER 72 FLAT WASHER 3 8 SAE NUT KEPS 3 8 16 Hex REAR MOUNTED EVAPORATOR 9 11 not shown not shown not shown Misc 40 62846 40 42838 40 62813 40 62849 40 62850 K 29 21901 40 52701 40 32477 40 03501 25 40 03502 25 40 03503 25 40 03504 25 28 71704 34 32401 40 20804 28 71713 40 02506 BOLT CARRIAGE 5 16 18 X 3 BRKT REAR HD SUPPORT LONG FLAT WASHER 10mm FLAT WASHER 5 16 SAE NUT KEPS 5 16 18 Hex NOTE ELECTRICAL SEE WIRING DIAGRAM Knob Fan for Rotary Blower Switch Control Clamp 1 Rubber Dipped Use for Main Wire Harness Edge Trim Seal 5 8 Rubber By the Foot Std 6 O Ring HNBR Green the 25 each package Std 8 O Ring HNBR Green By the 25 each package Std 4 10 O Ring HNBR Green By the 25 each package Std 4 12 O Ring HNBR Green By the 25 each package O Ring for Flare Fitting Drier Packaged with new drier Drain Tee 1 2 Drain Hose 1 2 1 16 wall Drain clamp 1 2 White Reusable Grommet Floor Hose 3 Plastic Tie Wrap 14 Sold By 1000 per package 4 19 05 9 12 06 Page 40 QTY REQ D 1 SET 1 1 optional use 1 optional use 1 optional use 1 optional use 1 1 1 1 o O N N N N gt N N Oo N 16 8 33 Ft A R A
25. NGAGE 4 If possible operate the blower only after using A C Ten to fifteen minutes would be great even better thirty minutes after using A C then run blower only for same amount of time This will dry any remaining moisture off the coil and greatly reduce odor potential Running the blower with out A C button on at the end of the run even for a few minutes is a good idea anytime of year THE ABOVE PROCEDURES IS DOUBLY IMPORTANT IF A SECOND EVAPORATOR IS TIED IN AS A SLAVE ON THE SAME CONTROL PACKAGE FAILURE TO STEP UP THROUGH THE SPEEDS AND A C ON FUNCTION COULD TRIP THE OVER CURRENT SAFETY CIRCUIT BREAKER AND DISABLE THE SYSTEM OMEGA does not recommend slave tie in of controls If two control packages are installed and the second unit is desired on then the second unit should not be turned on at the same instant Rather the operator should pause and turn second unit on separately following same ramp up procedure failure to do so can disable the System Maintenance will be asked to fully check wiring any time safety circuit breaker is tripped this could delay trip departures and incur expensive repairs If A C is accidentally turned off then wait 2 3 minutes before turning it back on This will add life to system as compressor need not start against higher head pressure the clutch will wear less and the drive belt will be less stressed at least for that one time NOTES If the system is tied into any other OEM automotive control t
26. OPERATION AND SERVICE MANUAL BUS AIR CONDITIONING SYSTEMS MODEL SERIES EF AND CS SPLIT SYSTEMS EVAPORATOR AND CONDENSER IN SEPARATE LOCATIONS FOLLOW ALL SAFETY AND OPERATION PRECAUTIONS INSTALLER REGISTER THE WARRANTY ON LINE AT WEB SITE www omega usa com OWNER END USER CONFIRM THE WARRANTY INFORMATION AND ENTER IN SERVICE DATE ON LINE AT SAME SITE Failure to comply may void warranty Maintain Service Records See back cover OMEGA ENVIRONMENTAL TECHNOLOGIES 10802 N STEMMONS DALLAS TEXAS 75220 214 357 1795 FREE 1 888 286 6342 WWW omega usa com P N 57 21002 Revision E 11 07 Available for review on line in PDF format Page 1 Limited warranty and warranty disclaimer for Omega Environmental Technologies Inc School and Transit Air Conditioning Systems Omega Environmental Technologies hereby warrants its State of the Art Air Conditioning System PRODUCT to the original purchaser PURCHASER when installed in a motor coach vehicle application either in the United States of America or Canada Warranty offered herein applies only to defects in workmanship and materials with the decision to repair or replace parts covered herein to be at the sole discretion of Omega Environmental Technologies Warranty Period The warranty period starts the day the Omega Product is installed on or in a commercial coach or school bus The warranty period is a minimum of 24 months 2 Ye
27. OR MILD SOAP AND WATER TO CLEAN ANY PLASTIC COMPONENTS WARNING In case of electrical fire extinguish with CO2 DO NOT USE WATER Turn off System Disconnect the battery ground cable if at all possible Do not risk injury to save replaceable machinery SERVICE AND MAINTENANCE PRECAUTIONS and WARNINGS All operation safety precautions apply SPECIFIC WARNING Do not oil blower motor shaft if replacing plastic wheel clean shaft of any oil present Replace spring clips with new part Page4 SPECIFIC CAUTION Do not allow oils to drip into plastic pan or any plastic part of these systems as material will absorb and become brittle and prone to crack USE THE CORRECT TYPE OF REFRIGERANT and OIL LISTED FOR A C SYSTEM Always wear protective eye wear and gloves when working with refrigerants and oils Always use mineral oil to lubricate O rings and threads of fittings CAUTION Always wear gloves when working with PAG or Ester oils as to prevent irritation of skin WARNING These oils can also damage vehicle paint plastic parts engine drive belts and rubber components like coolant and vacuum hoses PAG oil will absorb moisture and become very acidic and corrosive CAUTION Follow hose and fitting manufactures recommendations for replacing hose end fittings Oil is to be wiped cleaned from inside and outside of end section of hose for Bead Lock style fittings For E Z Clip oil the fittings nipple mineral oil on o rings F
28. R A R A R 8 Ft 50ea MODEL 1 MODEL CS1 CONDENSER 2 FAN 14 2 ROW COND DESCRIPTION QTY REQ D 1 24 30006 CONDENSER BUS 20 X 34 MIO 1 40 40127 BRACKET CONDENSER END 1 LEFT 28 00003 FLUSH MOUNTS FOR FANS 90 DEG 33 20004 CIRCUIT BREAKER 30 AMP 25 14854 D FAN 14 12V PULLER W WATER RESISTANT HP MTR 40 42830 DRIER BRKT M FOR 24 30105 37 10860 DRIER INLINE FILTER w o Sight Glass 35 13403 HARD LINE COND TO DRIER CEU picture wrong 40 42837 CONDENSER HARD LINE SUPPORT 10 40 42828 CONDENSER SHROUD 11 40 40128 BRACKET CONDENSER END 2 RIGHT notshown 28 42831 PLASTIC COVER BUS CONDENSER O O Q G N gt A cA AN 4 19 05 Page 41 MODEL 2 MODEL CS2 CONDENSER 2 FAN 14 4 ROW COND ITEM P N DESCRIPTION QTY 24 41523 COIL CONDENSER FOUR ROW s 1 2 40 40127 BRACKET CONDENSER END 1 LEFT 1 3 28 00003 FLUSH MOUNTS FOR FANS 90 DEG 8 4 33 20004 CIRCUIT BREAKER 30 AMP 1 5 25 14854 D FAN 14 12V PULLER WWATER RESISTANT MTR 2 6 40 42830 DRIER BRKT M FOR 24 30105 1 7 37 10860 DRIER INLINE FILTER w o Sight Glass 1 8 35 13403 ASS Y COND TO DRIER CEU picture wrong 1 9 40 42837 BRKT CONDENSER HARD LINE SUPPORT 1 10 40 40025 HOUSING CONDENSER FAN 1 11 40 40128 BRACKET CONDENSER END 2 RIGHT 1 4 19 05 Page 42 MODEL 3 P N 24 41525 1 40 32429 2 35 60005 4 40 40031 5 40 42830 6 40 40029 7 37 10860 8 35
29. RIALIZED TUBING BE INSTALLED OVER SERVICE CAPS EITHER BY INSTALLER OR MAINTENANCE Properly installed they will deter refrigerant theft and assure mechanic that system has not been contaminated Omega P N 41 10710 A system that the belt chirps when first engaged or squeals during start up needs belt tension checked This can be considered as normal that it might occur as belt is run in but it should be corrected as soon as possible See belt tension guidelines in maintenance section Follow up with visual inspection any time the hood is raised especially at engine oil service intervals The compressor mount should be examined carefully for the presence of all bolts and braces The installation center is 10096 responsible for the quality of workmanship in installing these Systems It is prudent to check engine compartment hose routing for adequate clearance from hot exhaust any moving parts like steering shaft and ABSOLUTELY NO POSSIBLE CONTACT WITH ANY BRAKE SYSTEM COMPONENT OR LINE HOSES TO COMPRESSOR SHOULD HAVE ADEQUATE CURVATURE TO ALLOW FOR ENGINE ROCK DURING OPERATION CHECK HOSE ROUTING AND SUPPORT UNDER THE VEHICLE Note that hoses may sag over a period of time and therefor may require clamping adjustment THE EVAPORATOR COVER SHROUD SHOULD FIT SNUG UP TO UNIT PUSH UP IN THE MIDDLE OF THE COVER AND IT SHOULD NOT DEFLECT MORE THAN 1 2 The cover needs to fit well to have blowers pull air through the cooling coil Omega provides
30. TUCK OPEN OR PARTIALLY OPENI IN THIS EVENT THE SUCTION PRESSURE WILL BE HIGHER THAN NORMAL AND THE HEAD PRESSURE WILL BE BELOW NORMAL See the following section REPLACING TXV Block Valve Defective valve diagnosis Two other indicators of poor compressor performance include rapid pressure equalization when turned off and an inability to pull a vacuum if the suction hose were pinched off this old procedure is not recommended as liner of hose may be damaged Compressors may be one of four basic types regardless they are all designed as vapor pumps As such it should transfer enough refrigerant to lower suction pressure to below 40 psi when properly sized to system and turned at road speed RPM Page 24 A noisy compressor that still pumps well may just need oil level service or removal level check See trouble shooting for other possible noise related problems Use an oil injector to slowly add several oz of oil into suction port up to 5096 of OEM charge for compressor model If removal checked and the compressor is oil dry but clean add recovered amount plus 50 of OEM charge back into suction port and follow all appropriate procedures to recharge If the compressor is inoperative and the system still has refrigerant pressure recover the refrigerant with approved machine Record amount of oil collected Remove compressor and drain oil into measuring cup Examine oil if the compressor broke and locked up right away the
31. UBE JACK COMP FEED TO COND TOP GRILLE ASSY BUS CONDENSER WITH OMEGA LOGO OPTIONAL FOR STACKING BRKT STACKER MOUNTING CLOSE OFF 4 19 05 7 17 07 MODEL CS5 SHOWN STACKED Page 44 WW W A FITTING IDENTIFICATION FEMALE FLARE MALE O RING MALE INSERT O RING MOR MIO FF OR FEMALE O RING FOR O EZ CLIP FITTING BEADLOCK FITTING Page 45 HOSE FITTINGS BULK HOSE PRESSURE SWITCH amp misc Parts BEAD EZ CLIP LOCK System 35 S1326 3 35 EZ1326 3 35 S1327 3 35 EZ1327 3 35 81326 35 EZ1326 35 81122 35 EZ1122 35 81122 1 35 EZ1122 1 35 51305 35 EZ1305 35 81405 35 EZ1405 35 81307 35 EZ1307 35 81407 35 EZ1407 35 86102 1 35 EZ6102 1 35 86103 1 35 EZ6103 1 35 86202 35 EZ6202 35 86204 35 EZ6204 35 81316 3 35 EZ1316 3 35 81317 3 35 EZ1317 3 34 13401 34 13402 34 13403 40 42704 34 70009 34 70010 34 70011 40 52702 29 30123 SAME P N 35 13337 SAME P N 35 13338 SAME P N 41 12139 FITTINGS Note LP long pilot SPzshort pilot esp at TXV 90 8 FOR X 10 With R134A Charge Port 16mm Ftg 90 10 FOR X 12 With R134A Charge Port 13mm 90 8 FOR X 10 hose 90 8 FEMALE FLARE X 8 hose 90 8 FEMALE FLARE W PORT 7 16 20 flare w schrader STRAIGHT 6 FOR SP X 8 hose Ftg STRAIGHT 6 SP X 8 hose STRT 10 FOR SP X 12 hose STRT 10 SPX 12 hose SPLICER Straight
32. VICE CAPS CHECK DUAL PRESSURE SWITCH CONTINUITY OPERATION Page 10 PLEASE MAKE COPIES NEEDED FILL IN INFORMATION amp ADD TO FILE OMEGA BUS SYSTEM MAINTENANCE CHECKLIST CUSTOMER NAME PHONE DATE Model Serial EV AP M S COND M S COMP R134a Data Plate Charge After Performance Check Amount Added 1 0 ANALYSIS R134a R 12 AIR H C or OTHER GAUGE TEMPERATURE READINGS BUS Mileage INITIAL HIGH SIDE psi LOW SIDE psi O RPM POST REPAIR HIGH SIDE psi LOW SIDE psi O RPM TEMPERATURE INITIAL AFTER COND TEMP POST REPAIR Amb Cond _ LOUVER TEMP INITIAL RETURN AIR TEMP DELTA T POST REPAIR DELTA T ATTACH COPY OF CHARGE DETERMINATION WORK SHEET insulation Bearing Noise Cleanliness Fittings Leaks Record Serial No s u Mounting Brackets Burned Loose Terminals M CLEAN or REPLACED Sight Glass Moisture Indicator 15 LOUVERS Fins Bent Damage Damaged Missing i s d Beaig Nose Fractures Leaks i l Page 11 TROUBLE SHOOTING THIS SECTION IS FOR BOTH OPERATORS AND MECHANICS Also please read introduction at front of manual Trouble shooting includes collecting enough information to locate the cause of the problem and correcting the problem This often means more than just fixing the obvious malfunction rather going further to fix the hidden cause Begin by gathering information provided by the operator this
33. amiliarize yourself with the proper operation of any service equipment you will be using Always follow manufactures instructions for recovery recycling equipment Failure to do so could cause personal injury or damage to the equipment Consult any manual or authorized service center prior to repairing any equipment Always unplug unit before attempting any maintenance Removing internal fittings and filters can release pressurized refrigerant Slowly release any pressure and wear appropriate safety gloves and eye protection CAUTION Use only Department of Transportation DOT approved cylinder for storing used or recycled refrigerant Approved cylinders are stamped DOT 4BA or DOT 4BW Store in approved cooler locations avoid heat WARNING High heat can raise internal pressure to dangerous levels US law requires certification for use and handling of refrigerants The use only UL approved heat blankets to raise the pressure of cylinder to aid transfer to system during charging Do not leave unattended or plugged in for more time then is required to perform service CAUTION Never use compressed shop air to leak or pressure test an A C system Under certain conditions pressurized mixtures of R134a and air are combustible In addition shop air will inject excess moisture into the system CAUTION Do not use open flame around refrigerants Avoid combustion engine operation when refrigerant leak is detected near intake area If accident occurs leave ar
34. and in contract tort including negligence strict liability patent infringement or otherwise with respect to the OET product furnished Authority To Change Or Modify The warranty described and defined herein can only be changed or modified by Omega Personnel This includes all terms conditions limitations rights or obligations Should OET offer a different warranty in the future it shall only apply to products sold when in effect and the terms Conditions and limitations of this warranty will not be transferable or subject to upgrading Version 001 03 23 1999 Page 2 Click the sections below number to directly to that TABLE OF CONTENTS SECTION Page Number GENERAL SAFETY NOTICES FIRST AID OPERATIONAL SAFETY 4 SERVICE and MAINTENANCE CAUTIONS and WARNINGS 4 INTRODUCTION FROM ENGINEERING DEPT 6 FROM SERVICE PARTS DEPT 6 MODEL NUMBERS AND SPECIFICATIONS 7 OPERATION NORMAL OPERATING INSTRUCTIONS 8 PREVENTATIVE MAINTENANCE NEWLY INSTALLED 9 PERIODIC AND SCHEDULED MAINTENANCE 10 SPRING CLEANING CHECKLIST 11 TROUBLE SHOOTING 12 MAINTENANCE EQUIPMENT 15 MAINTENANCE PROCEDURES 16 COMPRESSOR MOUNT BOLTS TORQUE SPECS 16 TORQUE SPECS FOR REFRIGERANT FITTINGS 16 COMPRESSOR DRIVE BELT MAINTENANCE 17 DRIVE BELT TENSION GUIDELINE 17 RETURN AIR FILTER RELAY BANK AND THERMOSTAT SERVICE 17 ODOR CAUSE AND REMOVAL 17 BLOWER MOTOR AND SPEED RESISTOR REPLACEMENT 18 CONDENSER FAN ASSEMBLY REPLACEMENT 18 REFR
35. appens when the steering wheel is turned hard This time the right belt gets adjusted the power steering belt Another bus service ticket says A C belt squealing this time the mechanic checks the system over and finds mud splash on condenser fins The coil is cleaned to fix the root cause as well as replacing the belt as it had indeed suffered damage This is trouble shooting taking time to look beyond the obvious In the previous example Did the mechanic also check that both fans were turning with correct voltage Did he also check that a rock had not smashed one of the pipes If he did then he was trouble shooting Next case insufficient cooling is the complaint The mechanic checks and sure enough the air filter is dirty so itis cleaned End of story not quite The performance of the evaporator is still low The system sight glass is also check and it is milky with bubbles and the high side pressure is also low The inspection continues until a leak is located the o ring is changed and the system is recharged adding back the amount of oil that was recovered with the refrigerant Now the bus is really fixed Next example it is time for the beginning of season scheduled maintenance The service proceeds and the performance appears a little low but the gauge readings are fine By performing a through inspection it is discovered that the tube after the receiver drier is cold and wet with condensate Referring to the basics when the refrige
36. arge Entering Compressor Cold Fitting with high suction pressure with Proper Charge Compressor failing See Compressor Replacement Procedure Add oil and retry or replace SERVICE EXPERIENCE TIPS In rare but significant cases oil has transferred out of the compressor and collected in the condenser and impeded refrigerant flow Significant because the system performance was way low and the problem is difficult to diagnose The symptoms draw a conclusion of bad TXV However having changed the valve twice the solution had to be found elsewhere in the system I don t remember who suggested it and was surprised with the results In desperation suppose the hot condenser was sprayed with cold water with system running The theory is that rapidly condensing the refrigerant dislodges the oil accumulation and forces it to circulate returning to the compressor In several other similar cases the water quenching did not work While system was open for TXV change the condenser was back flushed with nitrogen Special hoses were made so the exit hose was directed into a five gallon bucket The condenser was purged and a slug of oil was splattered all over the inside of the bucket use lid on bucket At first the flow seemed restricted then as the pressure built up the oil moved and slammed into the bucket relieving the pressure and finally was free flowing Even more rarely the oil slug was cleared from the evaporator coil The oil amount was est
37. ars This warranty period applies to the compressor The Evaporator and Condenser coils are warranted for 60 months 5 Years This warranty period is not limited by mileage or operating hours Warranty Coverage This warranty specifically covers all major components of the product either manufactured by or under the specifications set forth by OET such as but not limited to compressor evaporator assembly and condenser assembly The cost of replacing the refrigerant is covered only if the loss of refrigerant was due to a defective part covered under warranty Any item repaired or replaced under warranty will remain under warranty until the end of the original warranty period or for 90 days for the date of repair or replacement whichever is longer Items Not Covered By Warranty Omega Environmental Technologies products improperly installed modified in any way without prior written approval from OET disassembled or tampered with by anyone other than OET and products damaged by misuse negligence abuse accident corrosion fire water vandalism or explosion are excluded from warranty Product damaged by the original purchaser or any other third party including a vehicle dealer or service facility while performing work is not warranted by OET Service items requiring either replacement or adjustment such as but not limited to filters belts lubricants etc are not covered under warranty This warranty does not apply to any OET system or repla
38. bearing roughness complete pulley rotor Idler pulley bearing Check idler pulley bearing If rough replace idler Scrapping sound Inspect for dirt grit trapped behind front plate Remove and clean from clutch Check supply voltage Correct for low voltage Inspect for correct air gap space all around May be corrected with pry Remove and inspect for deep scoring Replace clutch Loose or missing compressor mounting Inspect and torque bolts if any are loose Replace any damaged bolts bolt s check mount holes and welds for damage Repair as required Loose or out of balance Remove and inspect retighten bolts Torque bolts engine crank pulley Check center machined fit Replace pulley Alternator water pump Locate the other engine driven component Replace component air pump or other with listening scope or other device ABNORMAL COMPRESSOR NOISE WHEN CLUTCH IS ENGAGED POSSIBLE CAUSE ACTION REMEDY Hose Resonating Check for any body or panel contact Add padding or clamp Excessive discharge Check for Poor air flow at condenser Clean coil replace bad fan Pressure Spray water on condenser listen for less noise Correct over charge Check pressures with gauge set See Note on Charge Recover Recharge W o Non Condensables Determination Work sheet Page 13 Compressor clutch Inspect clutch Check field coil c clip loose Repair to lock coil in place Liguid Refrigerant Check Suction Fitting for Frost or unusually Replace TXV Rech
39. been rapidly removed and set aside A complete recovery could take numerous hours If time were not an issue or if a person could plan the work schedule then recovery should be done during lunch or even better yet at the end of the day and then start machine again in the morning Recover refrigerant per machine manufactures instructions and stay informed with current industry journals for any legislation changes ADDING REFRIGERANT FULL CHARGE RECOVERED AND EVACUATED SYSTEM Note If using a charging station routinely calibrate it per manufactures instructions Page 21 Setup and pre heating of the supply cylinder is assumed have taken place during evacuation Place R 134a supply cylinder on weight scale that was set at zero and correct units are displayed Lbs or Kg Take note that an empty 3016 cylinder weights about 5 1 3 16 and the heater belt should also be on the cylinder so be prepared with enough refrigerant to compete the charge based on engraved plate attached to vehicle by installer After final evacuation close both all manifold valves Check that the cylinder valve is open and positioned correctly to dispense liquid Depending on condition and type of gauge hose set supply hose should be filled up to manifold valve if the hose was empty then the scale will show how much refrigerant was required to fill it Re zero the scale With the a c system off charge with liquid refrigerant into the high side only The heated cylind
40. cement product not properly serviced according to the manufacturer recommendation and or specification Any cost incurred by the purchaser including damage to or loss of vehicle or any part thereof for transporting the vehicle to an OET dealer or authorized service center loss of time or operating revenue or cost of using an alternate replacement vehicle is not covered Product failures as the result of an act of God such as but not limited to lightning earthquake windstorm tornado hurricane or flood are not covered Omega Environmental Technologies reserves the right to improve future product design without retrofitting existing products in the field to match the new specifications Obtaining Warranty Service To obtain warranty service for Omega Environmental Technologies units the product purchased must be returned to any authorized OET distributor or service center All warranty claims must be within the warranty period Any person applying for warranty service shall provide proper documentation that they are the original owner and the date warranty commenced Complete Warranty The warranty described in this document is the complete warranty for this product and is in lieu of all other warranties either expressed or implied including without limitation any implied warranty of merchantability of fitness or ability to successfully perform a specific purpose or job application OET hereby waives any obligation liability right claim or dem
41. ck of maintenance or neglect Claims in question must be supported by maintenance records if requested by OMEGA Example or Suggested Format Below Owner Operator Option if service dept has other proper records procedure and form in place PERIODIC AND SCHEDULED MAINTENANCE LOG See Pages 9 and 10 for Instructions Record Models and Serial s INITIAL NEWLY INSTALLED CHECK In Service DATE Performed By Print Full Name for School District Signed Name Weekly for First Month Name DATE Sign Weekly for First Month Name DATE Sign Weekly for First Month Name DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Quartery Name DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Quartery Name DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Off Season Name DATE Sign Winterized Pre Season Annually Name DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Quartery DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Quartery Name DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Quartery Name DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Quartery Name DATE Sign Monthly Name DATE Sign Monthly Name DATE Sign Quartery Name DATE Sign Monthly Name
42. e simply slowly open low side manifold valve do not allow suction pressure to rise too rapidly and no more than 40 to 50 psi Adding refrigerant gradually prevents the possibility of liquid slugging damage to compressor Allow sufficient time for the system to stabilize after each adjustment Normally five to ten minutes is sufficient for each two tenth 0 2 Lbs 3 2 oz added incrementally Check and record performance in chart form for each add to keep track and confirm final total Any time the cause is not known for head pressure in an elevated range then the system should be thoroughly checked for any other problem In this rare case that charge needs adjusting down then the system is turned off for vapor recover following machine instructions It would be possible to weigh the recovery tank and observe the amount transferred The alternative is to perform short intervals of recovery with system on performance checks each time COMPRESSOR REPLACEMENT Normally a compressor is not to be replaced unless it is not pumping the suction side down or is locked up Do not mistakenly replace a compressor when in fact the system is over or under charged The high side pressure may not raise if the system has a flow blockage or restriction A lack of flow will prevent the working fluid refrigerant energy transfer that results in high side pressure THERE IS ONE FAULT THAT MAY BE MISDIAGNOSED AS A BAD COMPRESSOR AND THAT IS IF THE EXPANSION VALVE IS S
43. e testing If nothing is visually obvious then next step of the preferred method is to charge the system with only enough refrigerant vapor to attempt build up to 30 40 psi and then add nitrogen to raise pressure to 150 200 psi There will be enough refrigerant for electronic leak detector to work and enough pressure for solution bubbles to form Do not operate system Remove the test gas locate and fix leak s replace filter drier evacuate dehydrate unit EVACUATION DEHYDRATION Double Nitrogen Flush and One Time Deep Vacuum Note Pag oil is very hydroscopic absorbs water DO NOT use oil from previously open containers Both Polyalkylene Glycol PAG and Poly Ester POE oil will pull moisture right out of the air Moisture causes a chemical reaction which creates ACID Evacuation will not remove the moisture and will not reverse the chemical process Moisture is always present in atmospheric air The presence of moisture in a refrigeration System will have undesirable effects Freezing up at metering devices acid and acid sludge formation and resulting in metal corrosion shorten the service life of an improperly serviced unit A double dry nitrogen flush evacuation should be performed after any catastrophic loss of refrigerant or any major component is replaced evaporator condenser or compressor By following good procedure capping lines and or limiting exposure time a single evacuation will normally suffice for minor service li
44. ea immediately WARNING DO NOT BREATHE ENGINE EXHAUST OF COMBUSTED REFRIGERANT FUMES CAUTION Turn off switches and disconnect battery ground cable when working on electrical motors controls or if shorting with tool is even a remote possibility CAUTION Completely disconnect battery if arc welding on vehicle CAUTION Even if someone has told you what is wrong with an A C system always perform a visual inspection prior to connecting gauge set If there is any chance that someone has used the wrong refrigerant or failed to evacuate system then fully dehydrate and recharge with correct refrigerant to avoid personal injury due to unpredictable high pressures developing in system CAUTION Nitrogen to be used with pressure regulator only Normally set a 125 psi or less 250 psi maximum DO NOT EXCEED NORMAL OPERATING PRESSURES DURING ANY SERVICE PROCEDURE WARNING Do not use oxygen in or near refrigeration system as explosion may occur WARNING Serious damage results when liquid refrigerant is sucked into the compressor Exercise caution when adding refrigerant to suction side of system Page 5 INTRODUCTION FROM ENGINEERING Routine maintenance of return air filters compressor drive belts tension condenser fins and fans will greatly enhance the cooling performance of these A C systems The service issues that place a refrigeration service mechanic in a separate category are addressed in this manual in a separate sectio
45. er will cool slightly as its elevated pressure forces fluid into system Shut off manifold valve when scale indicates the full charge Using this method eliminates the possibility of non condensable gas entering the system coming from the top vapor of a recovered recycled cylinder Start engine warm up and engage clutch Perform and operational test deemed appropriate See next section on charge determination When ready to disconnect to prevent trapping liquid refrigerant in the manifold hose set and robbing charge from system entire set must be brought to suction operating pressure First close the high side end coupling red knob fully counterclockwise Next slowly open both manifold valves allow both gauges to equalize at suction pressure Close the low side end coupling blue knob fully counterclockwise close both manifold valves Remove the low side coupling with system still running however high side will be hot and at high pressure at service port so it is best to wait until system is turned off and cooled down before removing the high side end coupling OPTIMUM CHARGE DETERMINATION The main goal is to provide maximum cooling and can be measured directly as temperature drop across the evaporator Delta T With R 12 the procedure was easy clear the sight glass and add a little to get sub cooled liquid supply to the expansion valve Now with R 134a this approach must be modified as the high side pressure can exceed optimum for s
46. essures add refrigerant evacuate and in rare cases equalize high and low side pressures The standard three hose version requires extra care in exchanging yellow service hose from cylinder to recovery machine to vacuum pump The more convenient four hose version has the advantage of allowing two service items to be connected at he same time Usually the cylinder remains connected and the recovery machine or vacuum pump are not used at the same time When it is time to exchange them the hose connection will have only a vacuum or very little pressure With the system OFF connect the service couplings to the service ports With all manifold valves closed rotate the end coupling valve red knob to move the plunger forward to open the service port schrader valve The high side pressure gauge will now indicate system pressure It will dependent on the average ambient temperature of the system not on the quantity of liquid in the system even if the system is low of charge just as long as there is some present to produce enough vapor present Next open the low side end coupling valve the low side pressure gauge should read the same as the high side system has been off long enough to equalize Too verify open both manifold valves check pressures again Any difference is GAUGE ERROR and should be noted usually as correction to wider scale high side gauge Closes manifold valves before proceeding With manifold gauges attached the system may now be run fo
47. hen refer to vehicle owners manual The A C system has a preset anti freeze up thermostat that will cycle the clutch and condenser fans on and off to prevent frost freeze up loss of air flow occurs and potential liquid slugging damage to the compressor It would be rare that an operator would notice this cycling However this should be considered normal if it occurs during extended run times IF HOWEVER THIS CYCLING OCCURS ON MODERATELY WARM DAYS DURING A SHORT RUN TIME THEN THE SYSTEM MAY NEED A MAINTENANCE CHECK for loss of refrigerant If unattended then maximum cooling will not be available on hot days The system also has a dual setting pressure switch on the refrigerant high pressure side line If the system has a massive loss of charge or is below 32 degrees the compressor will not engage Above approximately 28 psi the switch has continuity closed This low setting is referred to last resort charge loss protection The system should not be operated anytime it is not working well and you suspect loss of charge In addition the switch has a high pressure setting at 400 psi if the Page 8 system pressure rises to unhealthy level then the switch opens to prevent further operation until returns to operating range It is possible for the unit to cycle on this switch this would occur at an extreme case of high temperature operation possibly a failed condenser fan or obstruction at condenser inlet grille If cycling is noticed then rep
48. ibrate gauges see manifold gauge set usage and thermocouples comparative readings note any Correction Factor difference to be added or subtracted It is normal especially during light load operation for the TXV to hunt for setting thus suction pressures often range or swing This can also produce swings in high side pressures Record ranges or swings in readings NOTE If system is operated 30 deg above charge temp then recheck amp readjust charge Example If charged at 70 deg to 130psi then at 100 deg expect 250psi Whenever possible charge at hottest condition close to max expected during operation and obtain best overall performance Amb Guide Ibs Added 0 2 Added 0 2 Added 0 2 Added 0 2 Temp Line High Start or Into Desired Unknown If known If known If known If known Cond High See Record Total now Total now Total now Total now deg F Pressure Note Delta T Ibs Ibs Ibs Ibs Above High Low Pressures DT amp H L DT amp H L DT amp H L DT amp H L PLEASE MAKE COPY OF THIS FORM FILL IN ALL INFORMATION amp ADD TO MAINTENANCE FILE 62 110 64 115 66 120 68 125 70 130 72 135 150 74 140 155 76 145 160 78 150 165 80 155 170 82 160 175 84 165 180 86 170 185 88 175 190 90 180 195 210 92 185 200 94 190 205 96 195 210 98 200 215 100
49. ibration of unusual noise stop the system report to maintenance dept have service performed by qualified personnel When system is operating the high side pressure components fittings and lines or hoses will be hot enough to burn skin Do not attempt to touch or grab onto these components either during or thereafter until they have cooled High pressure lines hoses etc are not to be pulled on or wiggled while they contain pressure or premature failure might occur Same applies to low side components except they are cold during operation If a leak were caused by disturbing either then the temperature will drop INSTANTLY and may cause bodily harm If suspicious smell perceived like hot or burning materials then immediately turn off any switch associated with problem system and do not try to re operate Tag or tape off any controls have system diagnosed by qualified personnel Do not bypass any electrical safety devices Do not simply reset or bridge any overload device properly diagnose with ohm meter and ampere meter Do not use any sort of jumper wire in any electrical circuit CAUTION Avoid breathing any refrigerant vapor or lubricant vapor Exposure to these especially PAG oil mist may irritate your eyes nose or throat SPECIFIC CAUTION DO NOT ALLOW OILS DRIP INTO OR ON PLASTIC DRAIN PAN OR ANY PLASTIC PART OF THESE SYSTEMS AS MATERIAL WILL ABSORB AND BECOME BRITTLE AND PRONE TO CRACK USE ONLY APPROVED CLEANERS
50. imal Model CS6 3114 07 Percent for Cond ZTotal Q Model EF1 EF2 EF3 Evaporator 14 3 Model 4 Evaporator 10 0 If Evap is being replaced then 2 Evaporator add to total volume after Total is added get Decimal Evap Divided by ZTotal _ _ one Evap Extra hose for liquid use info below gne Evap Extra hose for suction use info below Hose for liquid Cond to Receiver Drier amp TXV 6 Hose 13 32 0 104 x length sft _ 8 Hose 1 2 0 131 xlength ft _ Hose for discharge Comp to Cond 8 Hose 1 2 0 131 x length ft hfd divided by Total 10 Hose 5 8 0 163 x length___ft Hose for Suction Evap to Comp 10 Hose 5 8 0 163 x length ft _ or 12 Hose 7 8 0 229 x length ft _ Receiver Drier 2 6 2 6 2 6 Total __ Add for each component that is in the system for Total Add all vertically from above 4 cont Figure out the Decimal for any component s being replaced ADD to the Decimal for the After Total is added get Decimal for any hose that is replaced hfl divided by Total hfs divided by Total ___ receiver drier as it will always be changed __ Q Total 5 Multiply step 4 Total by step 3 Total for final amount oil missing T x T 07 07 6 Add step 5 amount to 2 recovered amount plus 3 amount drained from compressor 5 oz 2 oz 3 oz oz Final Answer Total
51. imated and added back to the compressor suction port and the vehicles were never returned for additional service The how when and why of this oil transfer and collecting are not definable at this time The above cases are mentioned as possible solutions when dealing with a problematic system and the routine solutions have not corrected the performance problem KNOWING THE TYPICAL PERFORMANCE OF A SYSTEM CAN BE VERY VALUABLE IN SPOTTING THESE TYPES OF ANOMALIES TROUBLE SHOOTING EXTENDED FULL SYSTEM GUIDE Unit Not Air Conditioning Well POSSIBLE CAUSE 1 Dirty return air filter evap air flow blockage faulty blower motor 2 Air leakage around coil cover not fit correctly up to seals inside 3 Dirty condenser coil cond air flow blockage faulty fan motor or blade 4 Under charge Loss of Refrigerant 5 TXV stuck open eroded valve seat or needle 6 TXV stuck closed head charge loss restricted flow ice wax debris 7 Restricted receiver drier 8 Other system blockage dented pipe pinched hose collapsed liner 9 Slow compressor speed too small compressor for system 10 Belt slippage clutch slippage 11 Non condensable air in system 12 Severe over charged 13 Too much oil in system 14 Faulty compressor RELATED READINGS Low Suction Pressure See 1 4 6 8 13 High Head Pressure See 3 7 8 11 12 Low Head Pressure See 2 4 5 8 10 14 High Suction Pressure See 5 9 10 12 14 Page 14 MAINTENANCE EGUIPMENT Items may be o
52. installation training assistance however assumes no responsibility for installer errors omissions mistakes or workmanship in regards to installation or judgement of suitability of unit installed beyond the published data provided here within this manual Page 9 PRE TRIP INSPECTION After starting listen for abnormal noises from the evaporator condenser and engine areas Particular attention should be observed to confirm normal sound level of condenser fans in operation The blower speeds should be stepped through from low to high and confirm air flow at each speed PERIODIC AND SCHEDULED MAINTENANCE Schedule based on full season usage it may be adjusted depending on actual usage WEEKLY For the first month of service of new system Check compressor belt tension per instructions in maintenance section Check condenser inlet grill and coil fins for obstructions damage or excessive dirt Operate system and confirm all fans are operational Look at fittings hose connections for oil dirt traces that would indicate refrigerant leakage and report any abnormalities to maintenance MONTHLY Perform all listed above plus below Remove and clean or replace evaporator return air filter See maintenance section Inspect drain pan and clean as required check drainage hoses are clear and drain freely Check condenser fans operation QUARTERLY Perform all above plus below Inspect evaporator and condenser coils clean as requ
53. ion are the two most critical and controllable by the installer and end user When improperly installed and or maintained drive belts can cause significant damage to equipment as well as pose a safety issue Other factors include belt clearance temperature heat of use and fluids damage Alignment includes angular and parallel both should be obtained as close as possible Tolerance in mounting holes welded plates and plate flatness can cause misalignment When originally installed the mounting bolts may have been loosed and the pulleys aligned Later service work may require the same type of adjusting or shimming Short run life on a belt might indicate that a particular vehicle needs alignment checked A high quality straight edge and a precise measuring instrument like a dial caliper will be required to adequately check alignment Lay the straight edge across the pulley that protrudes the most usually the drive pulley on the engine measure to the edge of the belt and then compare to relative measurement of second pulley for parallel offset alignment Further check top bottom front and back to check angular alignment Make any correction required to achieve the best belt life Check idlers in the same manner as they too can wear on belt Drive belt tension if to light will promote slippage that will cause heat Over tension will stress bearings of driven component as well as early belt failure All belts require a run in period during the first
54. ired Check hoses and wiring routed under vehicle and in engine compartment for support Correct any wear chaffing or hose age sagging problem found Check torque of compressor mounting bolts Check voltage and current draw of components Investigate any component that has changed since last recorded marked reading If investigating then first check supply voltage at battery OFF SEASON FALL WINTER SPRING Perform all listed above esp Quarterly items plus below Inform driver operators about WEEKLY or at least MONTHLY operation listed above in operation section WITH ENGINE FULL WARM DURING THE WARMEST PART OF THE DAY OPERATE SYSTEM FOR 5 10 MINUTES TO CIRCULATE REFRIGERANT AND OIL THIS WILL ADD LONGEVITY TO THE COMPRESSOR SHAFT SEAL If possible operate the blower only thirty minutes or so later to dry any remaining moisture off the coil and reduce odor potential If your region uses road salt in the winter install Optional Winter Road Splash Cover condenser package ON PRE SEASON ANNUALLY Check for Optional Winter Road Splash Cover on condenser package Remove if present Perform all preventative maintenance listed previously SEE SPRING CLEANING CHECKLIST Fully operate system and check performance REFRIGERATION MAINTENANCE TO BE PERFORMED ONLY BY QUALIFIED PERSON WITH PROPERLY PREPARED GAUGE SET TO AVOID SYSTEM CONTAMINATION OMEGA HIGHLY RECOMMENDS TAMPER PROOF HEAT SHRINK TUBING BE REINSTALLED OVER THE SER
55. j i BK Black EF3 Fuses Lc PI BL Blue 20Amp H3 Relay Harness i dk BL Dark Blue 20 Amp HZ P n33 13712 i GR Green mp BL i 25 25 ps S S 15AmpL T Stat i RD Red YL Yellow WT White VT Violet Purple 33 20901 Rewire Is Possible To Up Speeds CI Color of Tracer 8 Current Draw of LEM change OR to 1 RD to 2 YL to 3 REVISION C JUNE 2007 CorelDRAW File buswire diad cdr Page 29 RECOMMENDED UNIT TIE IN WITH ONE COMPRESSOR SYSTEMSARE AFTERMARKET INSTALLED amp INSTALLER OPTIONS SHOULD FOLLOW THESE GUIDELINES IGN POWER IGN POWER 9 AB 19 al CB 5 40 Amp ite This End Q R 33 20005 Galo US IBN Tse ws gg nnne LH AIT Length po mu 70 100 M p SACS DEM or Installer s RD j vt Lyle High Capacity BN r ie e a hoe P eg Crimp and Solder 4 Fi ALL as The controls are E bv ID 29 H ground negative ite NES ATC Fuse of NEB Compressor S 75 Relay 2 Clutch JRDWT Rum ense BUTT ROTARY KNOB OPTION p 33 137 15 SPLICE PIN 35900 I6 Compt Assy W Pane 2 POWER TO MATCH 3 7 BLIWT COLORS z 4 I BK M High Side Dukl Pressure Safety SwitcH pin 29 2090
56. ke o ring leak repair Regardless a new receiver drier should be installed any time system is breached Keep the system ambient temperature above sixty degrees Fahrenheit to speed the evaporation of any moisture At lower temperatures ice may form before moisture removal is complete Remember also that the system will cool down as result of lowering the internal pressure Off season service should be performed in heated shop alternate heat source such as heat lamps will also help At least plan to perform evacuation during the warmest part of the day To get really technical see the note below For repair service first having recovered any refrigerant have vacuum pump service hooked up and ready to evacuate as soon as work is complete Make the drier replacement the last activity and immediately start vacuum pump Normally evacuate from both sides manifold valves both open Open valves slowly to prevent large inrush of air purging oil out of pump vent By hand turn compressor over several times once full vacuum is achieved Page 20 double nitrogen flush close low side manifold valve when adding nitrogen through high side Close high side manifold valve connect vacuum pump and evacuate by opening low side valve By hand turn compressor over several times once full vacuum is achieved After full evacuation depending on vacuum pump 10 to 30 minutes close low side manifold valve and stop vacuum pump and assure system holds vacuum fo
57. l Evacuate and recharge per proceeding sections COMPRESSOR OEM OIL AMOUNTS LIST Model BRAND OIL TYPE Viscosit OEM AMOUNT A 6 DELCO 15 118 PAG 150 295cc 1002 SD 510 SANDEN SP 20 PAG 100 150 5 102 SD 709 SANDEN SP 20 PAG 100 150 5 102 SD 7H15 SANDEN SP 20 PAG 100 135cc 4 5602 TM 16HD 1L PAG ZXL 100 PAG 46 150cc 5 102 TM 21HX 1L PAG ZXL 100 PAG 46 180cc 6 102 26 NLA 1L PAG ZXL 100 PAG 46 500 16 902 31HD 1L PAG ZXL 100 46 500 16 902 UP UX170 UNIDAP 7 PAG 46 160cc 5 4oz UP UX200 UNIDAP 7 PAG 46 180cc 6 1oz UX 260 UNIDAP 7 PAG 46 500cc 16 9oz UX 310 UNIDAP 7 PAG 46 600cc 20 3oz Note PAG oil is very hydroscopic absorbs water DO NOT use oil from previously open containers Both Polyalkylene Glycol PAG and Poly Ester POE oil will pull moisture right out of the air Moisture causes a chemical reaction which creates ACID Evacuation will not remove the moisture and will not reverse the chemical process KEEP COMPRESSOR CAPPED UNTIL READY TO CONNECT TO LINES AND INSTALL NEW RECEIVER DRIER BEGIN EVACUATION ASAP REPLACING RECEIVER DRIER The receiver drier w filter is located at the condenser Recover refrigerant following procedure above Have new component and o rings at hand to limit open system exposure time Carefully loosen fitting connections Remove and replace receiver drier replacing all o rings lubricated with mineral oil Receiver Drier Add 5 oz of c
58. llected in the recovery process initially seams quite obvious Normally with a system whose known service history is simple and for routine service like TXV replacement or leaking o ring replacement that is the best assumption For condenser evaporator and hose replacement determining or estimating the correct amount of oil to be added back for these components could follow these guidelines 1 Check the data plate for total amount listed for the system Bus system is typically 5 to 8 oz more than the compressor OEM charge Fill in blank at right with amount 2 Subtract the amount recovery collected Page 25 3 Remove the compressor and it Again subtract this amount THIS REMAINDER REPRESENTS THE MISSING OIL THAT IS DISTRIBUTED ____ THOUGH OUT THE SYSTEM FILM FORM ON INTERIOR SURFACES 4 Add up the total internal volume the Figure out the percentage of internal wetted volume that the replaced component contributed to the total wetted volume and add the drier percentage as it will also be replaced Work Sheet Percentage of internal wetted volume for replaced components Model CS1 Condenser 11 2 Fill in blank with for each item used Model CS2 Condenser 22 3 inthe actual system Use filled in 5 for Model CS3 Condenser 15 5 _ vertical Addition to get Total at bottom Model CS4 Condenser 12 3 If condenser is being replaced then Model CS5 Condenser 15 5 after Total is added get Dec
59. mpressor clutch drive plate at least ten times to distribute oil inside compressor and assure that itis not overfilled Install new o ring and reconnect suction fitting Again turn compressor by hand to assure oil distribution Remove and replace receiver drier replacing all o rings lubricated with mineral oil Evacuate and recharge per proceeding sections ADDING OIL WHEN COMPONENT IS REPLACED when reusing same compressor THIS IS PERHAPS THE MOST DIFFICULT DECISION FACED BY THE SERVICE TECHNICIAN Research has proven that too much oil in a system will degrade the performance but a system without enough oil will likely have a premature compressor failure The first thing that makes sense is that any time a major component is replaced then oil should be added to make up for the loss Consider refrigerant as a major component During recovery removal of R 134a from the system oil in mixture is also removed Refer to specific machine instructions regarding oil collection It is often noticed that the oil collected and then drained from machine foams up as the refrigerant in solution is exposed to less pressure Allowing time for correct and accurate measurement of oil removed is vital Complete drainage of machine collecting system may require repeated attempts Some machines have an internal recycle mode that may need to be performed to completely separate the oil from the recovered refrigerant Adding back new oil to replace that amount of oil co
60. n Basic understanding of vapor compression refrigeration cycle is essential Most all refrigeration service relies on the basic principals for proper diagnosis and service procedures Although this manual is not intended to be a basics text it does cover a lot of basic service information that is worth review You will also find specific service recommendations specifications for OMEGA bus systems as well as some unique excerpts based on field experiences from our staff Hopefully operators service writers and mechanics will all read pertinent sections We especially invite everyone to read the trouble shooting section and find it both entertaining as well as informative The number one failure in terms of difficulty is locating the leak that has caused the loss of refrigerant from today s A C systems Locating leaks is now more difficult with R 134a and the synthetic oils required then it was with R 12 First off the R 134a molecule is smaller and more slippery than R 12 Secondly PAG and Ester oils evaporate thus the tell tale oil of a leak may or may not be found Leaks in coil bodies are extremely rare however leaks at brazed joints do occur and when the coil is encased or shrouded finding the leak can be quite a challenge GOOD LEAK DETECTION DEVICES ARE REQUIRED OMEGA HIGHLY RECOMMENDS THE ADDITION OF UV DIES TO ASSIST IN LOCATING LEAKS The number one failure in terms of difficulty to diagnostic is or can be electrical problems Once more
61. n oil will likely appear mostly clean and perhaps with some small metal particles In this case a nitrogen back flush of condenser and hose from compressor is still recommended The receiver drier should have collected any other debris If however the oil appears black or dirty then all the system components should be individually nitrogen back flushed reverse direction to regular flow first Solvent flush may also be used to back flush and will often dislodge particles oil stuck in the condenser then the trick is to fully remove the solvent with nitrogen Carefully follow instructions provided with these types of products The only proper way to final flush the system is to use refrigerant in a closed loop system Closed loop flushing kits are available and some recovery recycle machines have flush kit options If the system was judged to be acceptably clean then drain new compressor and add back the amount drained from old compressor or 5096 of OEM oil charge whichever is greater plus amount collected in recovery machine If system was flushed and the receiver drier is the only other component being replaced then check OEM charge amount and add oil to compressor to achieve total amount listed on data plate Oil is to be poured into compressor suction port Remove both caps from ports of compressor verify that compressor is indeed pre oil charged rebuilt compressors are often shipped dry Add correct amount of oil By hand turn the co
62. on Spray Bottle min Radiant Leak Detector Solution better Electronic Leak Detector and replacement tips P N 41 15202 DVOM Digital Volt Ohm Meter and Ampere Meter Single wire clamp Selection of Electrical End Connectors Ring Terminals Star Washers Etc High Grade Electrical Contact Cleaner Electrical Tape Tie Wraps Heavy Duty Anti Chafe Material Mill Hose Similar to Fire Hose Fin Comb Foaming Coil Fins Cleaner Omega P N 41 19990 Odor Eliminator CLEAN AIR BRAND P N 41 00001 2 5 oz Spray can CLEAN AIR BRAND P N 41 00003 1 gallon with Sprayer Hose REPLACEMENT PARTS see parts brake downs at end of booklet O RING SELECTION see parts brake downs at end of booklet Page 15 MAINTENANCE SERVICE PROCEDURES NOTE FOR REFRIGERATION RELATED SERVICE CONTINUE TO THAT SECTION MAINTENANCE PROCEDURES GENERAL NOTES FOLLOW ALL SAFETY AND OPERATIONAL PRECAUTIONS WARNING THE UNIT MAY CYCLE ON THE FANS AND COMPRESSOR UNEXPECTEDLY AS CONTROL REQUIREMENTS DICTATE BEWARE OF UNANNOUNCED STARTING REMOVE POWER PRIOR TO TOUCHING COMPONENTS THAT NORMALLY MOVE REFERENCE FOR COMPRESSOR AND MOUNT BOLTS CHECK QUARTERLY TORQUE SPECIFICATIONS BOLTS INTO ALUMINUM OR CAST IRON THREADS Note Max value based on oil in threads and on head bearing surface Clean dry values would be slightly higher S A E BOLTS TORQUE IN FOOT LBS GRADE 8 HIGHLY RECOMMENDED FOR ALL ENGINE MOUNTED BOLTS Follow any information from mount manufacture if available
63. orrect oil plus recovered amount REPLACING HIGH PRESSURE SWITCH This component may be on a fitting at the condenser or spliced in on the liquid supply hose after the condenser before the TXV With system still pressurized check for continuity The switch is depressing a schrader valve and may be replaced with out dropping the refrigerant charge The Switch may be checked with a special setup of a schrader valve to the nitrogen regulator Spec for P N 29 30123 Dual Switch Open until approximately 28psi closed until 400psi 40psi REPLACING TXV Thermostatic Expansion Valve SPECIFIC CAUTION Do not allow oils to drip into or on plastic drain pan or any plastic part of these systems as material will absorb it and become brittle and prone to crack The block valve is located at the evaporator coil Unit cover must be removed and valve should be diagnosed as needing replacement before proceeding Defective valve diagnosis First make a temporary blower close off out of cardboard to draw air through evaporator coil and tape in place Operate system on low blower and hand warm the bare disc head of the valve while observing may require an assistant the gauge set The suction pressure should raise as the valve opens up discontinue warming immediately to prevent liquid slugging the compressor Next operate the system on high and cool the bare disc head cooling the head may be accomplished by spraying the head with nitrogen evaporator deodo
64. ort all known factors to maintenance PRE TRIP INSPECTION After starting listen for abnormal noise from engine and condenser areas PARTICULAR ATTENTION SHOULD BE OBSERVED TO CONFIRM NORMAL LEVEL OF NOISE TO CONFIRM CONDENSER FANS OPERATION The blower speeds should be stepped through and confirm airflow at each speed OFF SEASON OPERATE SYSTEM WEEKLY OR AT LEAST MONTHLY WITH ENGINE FULL WARM DURING THE WARMEST PART OF THE DAY OPERATE SYSTEM FOR 5 10 MINUTES TO CIRCULATE REFRIGERANT AND OlL THIS WILL ADD LONGEVITY TO THE COMPRESSOR SHAFT SEAL If possible operate the blower only thirty minutes or so later to dry any remaining moisture off the coil and reduce odor potential PREVENTATIVE MAINTENANCE PLEASE READ ALL SECTIONS THAT FOLLOW FOR TIPS AND INSIGHT THIS MANUAL IS NOT A SUBSTITUTE FOR INITIAL FULL TRAINING IN SYSTEM DIAGNOSIS OR REFRIGERANT HANDLING NEWLY INSTALLED The warranty card should be properly completed by installation center installer E MAIL REGISTRATION INFORMATION at OMEGA WEB SITE REQUIRED for 2004 forward NEW SYSTEMS ARE TO BE THOROUGHLY CHECK BY THE INSTALLER PRIOR TO DELIVERY However it is very prudent to inspect the newly installed system for compliance to contract specifications The metal system component ID plate should be examined for completeness and readability upon delivery rather than several years later when the system develops a problem OMEGA RECOMMENDS TAMPER PROOF HEAT SHRINK SE
65. ptional depending on level of service Protective Eye Ware Insulated Gloves eye wash station first aid kit all other safety equipment Torque Wrenches Schrader Valve Service Tool OMEGA P N 41 91290 Belt Tension Gauge P N 41 93862 Straight Edge Ruler and Dial Caliper Dual Thermocouple Digital Thermometer Manifold Gauge Set with Hoses and End Couplers for R 134a service ports P N 41 89772 Complete Recovery Recycle Machine with closed loop flush kit option Drilled out TXV Block Valve Vacuum Pump two stage 7 CFM minimum capable of 500 to 25 micron vacuum P N 41 90057 Vacuum Pump 22 oz service change for above P N 41 90022 or Vacuum Pump two stage 5 CFM minimum capable of 500 to 25 micron vacuum P N 41 90056 Vacuum Pump Oil 16 oz service change for above P N 41 90016 Micron Vacuum Gauge Nitrogen Bottle Cylinder with Pressure Regulator and Gauges R 134a Refrigerant Supply Cylinder Heater Wrap for Refrigerant Cylinder Pressure Elevation Accurate Weight Scale P N 41 15220 Oil Injector Capable of adding Oil and Dye to Closed System with Pressure UV Dye Additive or Oil with Dye UV Light Source and Protective Eye Ware Correct Viscosity Compressor Oil See OEM Oil Charge List Solvent Flush Kit and Supplies P N 41 91046 Power Flushing system P N 41 01490 OZ ML CC Graduated Beaker or Cup for measuring oil Small Container Dispenser with Mineral Oil R 12 compressor oil Soap and Water Soluti
66. r a minimum of five minutes some pressure rise may be observed on a micron gauge say about 500 microns but this would be completely unperceivable on a compound gauge If system does not hold vacuum then diagnose leak with preferred method above partial refrigerant Upon successful vacuum hold test repeat dry nitrogen purge through high side procedure again only this time loosen low side hose at manifold and allow nitrogen to flow through system to flush out any moisture that vaporized boiled off during vacuum hold test Final evacuation to dehydrate the system should be to below 1000 microns Alternatively a single double or triple refrigerant flush will work similarly except recover the flush through refrigerant for proper recycling If the system has been open or empty for a long time then evacuation times should be extended and triple flush with full evacuations between is required Single flush evacuation 30min is 90 efficient Double 97 Triple flush evacuation 99 effective moisture removal One time deep vacuum is for new systems not previously charged and minor short duration breach repaired systems By hand turn compressor over several times once full vacuum is achieved After full evacuation depending on vacuum pump 15 to 30 minutes close low side manifold valve and stop vacuum pump and assure system holds vacuum for a minimum of five minutes some pressure rise may be observed on a micron gauge say about 500 micron
67. r annual pressure reading check see the system performance chart for procedure If some service is determined to be required then proceed with full diagnosis of system prior to adjusting charge of refrigerant First see leak check and then adjusting the charge below After testing is complete to prevent trapping liquid refrigerant in the manifold hose set and robbing charge from system entire set must be brought to suction operating pressure First close the high side end coupling red knob fully counterclockwise Next slowly open both manifold valves allow both gauges to equalize at suction pressure Close the low side end coupling blue knob fully counterclockwise close both manifold valves Remove the low side coupling with system still running however high side will be hot and at high pressure at service port so it is best to wait until system is turned off and cooled down before removing the high side end coupling REFRIGERANT LEAK CHECK SYSTEM WITH PRESSURE If pressure reading were diagnosed to require adjustment then most likely it was determined that some loss of refrigerant has occurred So depending on the amount that needs to be added how severe is the problem Was it a very small amount that could be called normal permeation or a larger amount indicative that a repair is required In either case the correct thing to do is to carefully go over the system and fix any leak that can be identified It is only going to get worse
68. r cover and on the wiring diagram of this manual that should stay with the bus and or kept on file for the fleet INTRODUCTION FROM SERVICE PARTS DEPT In the following pages and at the end of this booklet you will find part numbers for service items and replacement parts for the OMEGA Bus Systems We hope you never need to replace a single component however we know that hard working fleet units accumulate run time hours rapidly and systems require maintenance and service as a result of demanding operating environments PLEASE NOTE THAT A LOT OF THE COMPONENTS ARE GENERIC INDUSTRY WIDELY USED ITEMS AND ARE THEREFORE AVAILABLE WITH CROSS REFERENCE TO OTHER MANUFACTURES UNITS WE INVITE YOU TO CHECK WITH OUR KNOWLEDGEABLE STAFF FOR ALL YOUR REPLACEMENT PARTS NEEDS WE PRIDE OURSELVES IN PROVIDING QUALITY PARTS WITH RAPID SERVICE Page 6 BASIC MODEL NUMBERS AND SPECIFICATIONS SCHOOL BUS EVAPORATOR UNITS MODEL TYPE BLWR S RATED 13 5VDC BASIC DESCRIPTION RATED BTU zero static 27 19522 EF1 FB F R SM 750 CFM 14 2 AMPS ONE MTR DOUBLE SHAFT 40 000 27 19520 FBF R SM 1150 CFM 22 4 AMPS TWO MTR DOUBLE SHAFT 52 000 27 19526 EF3 FBF R SM 1315 CFM 37 2 AMPS ONE MTR DOUBLE SHAFT 54 000 amp TWO MTR SINGLE SHAFT 27 42014 EF4 IN WALL 1140 CFM 31 2 AMPS TWO MTR DOUBLE SHAFT 45 000 SCHOOL BUS CONDENSER UNITS MODELTYPE FAN S RATED 13 5VDC BASIC DESCRIPTION 24 30105 CS1 SKIRT MTG 2490 18 4 AMPS TWO 14 FANS 2Row COND
69. rant flow is restricted the pressure and temperature is lowered that s what happens at the TXV right Well in this case the partially clogged receiver drier is throttling back the flow the reduced pressure before the valve does not allow it to function properly There is no substitute for full proper training and experience when trouble shooting A C problems In the preceding paragraphs of examples it was shown that the better a problem is understood the more easily the correction can be made In the shop the better a person understands the inner workings of a vapor compression refrigeration system the quicker and more correctly will the root cause of a problem be diagnosed One survey revealed the following percentages for A C components that required maintenance in a particular fleet Belts 32 Compressor clutch 26 Condenser 12 Add Refrigerant 1296 Refrigerant Lines Fittings 11 Valves 7 In this survey electrical problems were not included Page 12 Electrical trouble shooting normally starts at the end of a wire be it a component connector Check the wiring diagram to find the components that are involved in the malfunction start with whatever seems easiest or most likely Check for continuity through the component s If that doesn t work then check for power or ground trace which ever leg is not reading correctly Example Problem The clutch slips when engaged it looks like it has been getting hot and there is rust
70. rizer aerosol or applying ice observing the gauge set The suction pressure should drop as the valve closes discontinue head cooling immediately to prevent system from operating below ten psi as this will starve the compressor of return oil and possible overheat with out the refrigerant vapor cooling effect If the valve responded then perhaps it is not the problem after all Having exercised the valve observe system operation after system has stabilized If the valve did not respond then it should be replaced Recover refrigerant Have new component and o rings at hand to limit open system exposure Page 27 time Carefully loosen fitting connections Remove and replace valve replacing o rings lubricated with mineral oil Reproduce any insulation that was on original valve and fittings END Page 28 RECOMMENDED ELECTRICAL WIRING DIAGRAM MODELS EF1C EF2C amp EF3C SYSTEMS ARE AFTERMARKET INSTALLED amp INSTALLER OPTIONS SHOULD FOLLOW THESE GUIDELINES ACCY KIT 36 00026 OR BDS Body Disconnect Solenoid Normally Supplied has RELAY 75 Amp on gt M od OEM or Installer OMEGA p n 30 13416 Harness amp C B 7 100Amp 4 Post may be ordered separately Crimpand Solder ROTARY KNOB PUSH BUTTON CONTROLS x ALL as Req d BUTT P N 33 50018 Complete Assy w Panel Na
71. s but this would be completely unperceivable on a compound gauge If system does not hold vacuum then diagnose leak with preferred method above partial refrigerant Upon successful vacuum hold test restart pump for another 10 to 20 minutes Final evacuation of the system should be performed at above 60 degrees temperature Note VACUUM TO WATER VAPORIZATION TEMPERATURE Compound gauge readings inches of Hg is read as inches of mercury vacuum 28 92 inches of Hg 96 6 vacuum 25 400 microns boiling point of water is 799 229 13 inches of Hg 97 4 vacuum 20 000 microns boiling point of water is 72 29 80 inches of Hg 99 4 vacuum 4 500 microns boiling point of water is 32 F 2029 88 inches of Hg 99 86 1 000 microns 1 mm of Hg Absolute Pressure RECOVERY NOTES Prior to recover drain oil from collection container that may have settled since last use note this amount Learn the characteristics of your machine If it retains oil then consider adding the value to the amount collected After recovery record amount collected for add back calculations The machine may cycle off and then back on in about five minutes or more In fact as refrigerant continues to come out of solution from the PAG oil in the system it will raise pressure This slow process may be observed when a component is removed capped and checked for pressure later It sure makes a mess when the bubbling oil comes out of an evaporator or condenser that has
72. se mild soap and water with brush to clean carefully use shop air to dry apply spray filter enhance directly to screen as desired per manufactures directions Note if thermostat probe was pulled out of coil then reinstall between coil fins right next to original location to re establish full contact Carefully reinstall all components Page 17 ODOR CAUSE AND REMOVAL This is service matter not warranty issue Odor is caused by naturally occurring bacteria growing in any water remaining in the evaporator housing drain pan drain hoses and perhaps on coil Because of the low temperature of the air limited discharge flow that might otherwise flush growth away and in the absence of sunlight an ideal situation for the growth of bacteria and fungi is unavoidable created To remove the odor remove the microbiology By properly cleaning components of dirt formed from dust that holds water the colony will not have it s first foothold Washing with white vinegar is probably the most effective method of removing the contaminants A popular effective option between complete cleanings is to routinely use a spray A C deodorizer that will freshen by chemically neutralizing nature s little troopers Also see operation procedures to run blowers only to dry unit BLOWER MOTOR ASSEMBLY and SPEED RESISTOR S REPLACEMENT Disconnect battery ground cable Follow same procedure as return air filter service Disconnect wiring remove failed component
73. usually is vague like It don t work or It don t cool This same type of information may be on the work order This type of sketchy information normally will result in the repair diagnostics taking longer Please allow the following set of examples In the first scenario using a vague work order the bus A C system is checked out for performance and every thing is fine The mechanic spends a full hour and the bus is returned to service bus unfixed The same bus comes back sometime later with the same complaint At the time of the second request for service the operator and service writer get together and provide more concise information The work order reads the blower speeds all work and the unit works fine at the beginning of each daily run but cooling and air flow are way off at the end of several hours of running Provided with this information and understanding the function of the thermostat then the mechanic does a quick check change of that component and the freezing up is fixed In the next example the operator says there is sometimes a squealing noise under the hood The service writer fills in A C belt is slipping The mechanic does not hear the noise when he runs the system but he tightens the A C belt anyway just like the work order said The bus is returned to service and comes back the next day with the same complaint This time a different operator says there is sometimes a squealing noise under the hood and it usually h
74. ystem maximum flow rate So the sight glass is now used mainly for moisture eye reference A system that is otherwise sound but is low on refrigerant will produce a better Delta T as refrigerant is added system must stabilize between incremental additions Recording all temperature readings and both high and low pressures will help to see the trend Notice that single point thermocouples have a difficult time in moving air streams recording high to low swings is required The method also requires near maximum heat load conditions for best results It should be performed with windows open to reduce re circulation air effects and to attempt to have steady state inlet air temperature and humidity Another charging method is to measure the ambient air temperature at the condenser inlet enter the temperature pressure chart read the corresponding pressure value and adjust system charge to obtain same high side gauge reading This procedure does not assure maximum cooling performance Omega recommends a combination of the two methods The engine should be running at about 3 4 of max road speed RPM Incrementally add charge to obtain the best evaporator performance Have the pressure value on hand and consider it as the maximum except if the delta T performance is still getting significantly better As an example two degrees better delta T for a 5 to 10 psi rise above the chart value If the system were way undercharged to start you will see that the delta

OPERATION AND SERVICE MANUAL - Omega

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