Thomas & Betts RZ-NA 441-OMS User's Manual
Contents
1. Cause and Remedy cont d 14 Disconnect closed blower and burner switches in run position control Air in pilot gas line bleed pilot line switch is in winter position control power high gas normal low Inadequate pilot gas pressure verify pilot gas pressure 3 5 w c gas normal firestat normal system switch energized starter 3 Faulty pilot valve replace pilot solenoid valve energized and freezestat normal lights are lit ignitor has reached Faulty ignition module replace entire module 1 4A and has opened the pilot valve bringing on the pilot valve normal light but the pilot flame is not present After two trials the unit will go into safety lockout requiring cycling of the main disconnect switch 15 Disconnect closed blower and burner switches in run position Microamp signal on flame rod is inadequate check position and control switch is in winter position all status lights are lit condition of flame rod and signal minimum 0 5 microamps required except main valve normal light The pilot flame is present Grounding for unit or flame rod inadequate check ground path and stable but the low stage portion or main gas valve will not Faulty main gas valve replace main gas valve open or rapid cycling of the main valve is occurring Faulty ignition module replace ignition module Inadequate main gas pressure verify main burner pressure 16 Disconnect closed blower and burner2. Dirty Filter Switch Limit Control Pressure Null Switch Drive Components Main Burner Sensing Pressure Check Electronic Circuit Board with Maintenance Schedule Troubleshooting Diagnostic Lights Maintenance Section Wiring Diagram Emergency Cut Off Maintenance Service Access electrical box on the unit O iy homas Betts 2001 Thomas amp Betts Corporation All rights reserved Printed in the U S A MANUFACTURER OF HEATING COOLING AND VENTILATING SYSTEMS Trademark Note Reznor is registered in the United States and other countries 800 695 1901 www ReznorOnLine com Page 12 8 01 YL Form 4410MS Version 1
3. Disconnect the two ignition wires male and female quick connec tions and disconnect the flame sensor lead at the burner Remove the set screw located in the ignitor tube set screw holds the brass bushing in place Carefully remove the brass bushing and the igni tor Check the hot surface ignitor for cracks or unusual deterioration Check the flame rod for integrity Replace the flame rod P N 131188 and or the hot surface ignitor P N 121865 if not in good condition 4 Clean the burner and pilot by back flushing using high pressure air 40 80 Ibs Continue until dust particles are completely expelled from both the upstream and downstream sides of the burner CAUTION Wear eye protection while pressure cleaning and drilling Page 4 Figure 5 Burner End Plate showing Hot Surface Ignitor Burner End Plate Flame Sensor Ignitor If air pressure does not unplug burner orifices or pilot tube drill burner orifices with a Size 50 drill and or pilot tube with a Size 55 drill WARNING Do not enlarge burner ports or performance may be drastically affected Inspect the upstream and downstream sides of the mixing plates Remove any accumulation of scale or foreign material with a wire brush If any mixing plate fasteners are loose or missing tighten or replace Always use zinc plated or stainless fasteners If any cracks are present replace that mixing plate Because of the effect of flame temperature on the
4. Guide Check the diagnostic lights on the circuit board References Installation Manual Form RZ 441 Replacement Parts Manual Form RZ 741 FOR YOUR SAFETY WARNING The use and storage of gasoline or other flammable vapors and liquids in the vicinity of this appliance is hazardous If you smell gas 1 Open windows 2 Don t touch electrical switches 3 Extinguish any open flame 4 Immediately call your gas supplier WARNING Improper installation adjustment alteration service or maintenance can cause property damage injury or death Read the installation operation and maintenance instructions thoroughly before installing or servicing this equipment KEEP THIS BOOKLET FOR MAINTENANCE AND SERVICE REFERENCE Operating Maintenance Service Instructions The information in this manual applies to Model Series DV di rect fired heating makeup air systems As with any gas burning equipment regular maintenance procedures are required to en sure continued safety reliability and efficiency of the installa tion If service is required this system should be serviced only by a qualified service person Service information in this booklet is intended as a guideline for a qualified gas fired equipment ser vice person Mfg No 161442 Pagel DANGER The gas burner in this direct gas fired system is designed and equipped to provide safe and economically controlled complete combustion However if
5. 23 Damper Motor Figure 24 Potentiometer P N 16110 Figure 25 Pressure Null Switch a building pressure sensor P N 88052 14 Inlet Air Controls cont d Pressure Null Switch cont d building pressure It maintains a selected positive or negative pressure setpoint by changing the amount of outside air being introduced to the building through modulating outside air damper As more pressure is required in the building the pressure null switch activates the damper motor driving the outside air damper towards the full open position causing the bypass return air damper to go toward the closed posi tion Conversely as less pressure is required the switch drives the outside air damper in the opposite direction Service Clean the tubing and the screened ends of the pressure tap vents Be sure that the switch is installed with the diaphragm in a vertical plane and that the pressure taps are sheltered from the wind For further service follow the manufacturer s instructions included with the switch Photohelic Pressure Switch automatic building pressure sensor Description Function The photohelic pressure switch is a phototransister relay operated positive pressure switch used in makeup air applications to automatically control building P N pressure It maintains a selected 159893 positive pressure setpoint by changing the amount of outside air being introduced to the building through a modulating outside
6. 81 1 70 65 5 59 2 13 1 70 265 1500 8 05 3 07 6 85 2 61 2 44 93 8 05 3 07 2 44 93 1750 10 96 4 17 932 3 55 3 33 1 27 10 96 4 17 3 33 1 27 2000 14 31 5 45 12 18 464 434 1 66 14 31 5 45 4 34 1 66 2250 18 11 6 90 15 411 5 87 5 50 2 09 18 11 6 90 5 50 2 09 2500 22 36 8 52 19 021 7 25 6 79 2 59 22 36 8 52 6 79 2 59 2750 8 21 3 13 8 21 3 13 3000 97I 3 42 QIT Bee Gas Pressure Switches If the gas train includes either or both high and low gas pressure switches the switches monitor gas pressure downstream from the safety valves Figure 20 Gas Pressure Switches Ifthe gas pressure in a system equipped with a high gas pressure switch Op tion BP2 exceeds the setpoint the switch will open the electrical circuit to the burner stopping all gas flow The high gas pressure switch is a manu ally reset device Low P N 93850 automatic A low gas pressure switch Option BP3 will shutoff the gas flow if the gas pressure drops below the setpoint of the low pressure switch The low gas pressure switch will automatically P reset when the gas pressure rises above High P N 93849 the setpoint l manual reset NOTE Both high and low gas pres sure switches incorporate a vent lim
7. Location 1 Manual Reset Limit Switch is mounted on a 2x4 electrical box located in the blower section To access the manual reset remove the blower section access panel to the left of the discharge left when facing the discharge 2 Emergency Cutoff Limit Control is in the burner control cabinet just above the electri cal box e Manual Reset Limit Control Blower Cabinet Function The Figure manual reset limit Manual Reset Limit is a temperature activated safety o F control Re start Capillary tubing is_ F P of the system can in a holder that _ be done only after extendsintothe Se the limit control is cooled and the reset button is depressed CAUTION If the manual reset limit activates find and correct the cause before re starting the system Service Failure of the manual reset limit requires replacement of the control Page 5 8 Temperature Limit Safety Controls cont d Attach a slope gauge 0 to 1 0 scale to the tubing connections in the as control compartment The two connections are located below the elec Emergency Cut Off Limit Control trical control box Remove the caps on the 1 8 NPT test connections Function The emergency cut offis a fus and attach the slope gauge The recommended method for attaching the ible link high temperature limit which pro Figure 11 ECO slope gauge is to use field supplied 1 8 female NPT x 1 4 O D barbed vides one time redundan
8. are comprised of Maxitrol Series 14 controls Options AG30 and AG31 systems electronically maintain a constant discharge air temperature in the range of 55 90 F 55 75 F for C G A Option AG31 includes an overriding thermostat Option AG32 system will maintain a constant discharge air temperature in the range of 80 130 F Option AG35 maintains a discharge temperature range of 120 160 F Figure 15 Components of the Gas Control System Maxitrol Series 14 used in Gas Control Options AG30 AG31 AG32 and AG35 i f Temperature Temperature _ Selector Sensor Option AG33 electronic modulation system is comprised of Maxitrol Series 44 controls The low limit 20 60 F and the high limit 60 140 F for con trol of discharge air temperature are set at the amplifier located in the control compartment The space temperature is set at the remote selectrastat 55 90 F range located in the space When the temperature is below the space temperature setpoint the control system operates the burner to automati cally adjust the discharge air temperature within the maximum and minimum limits set on the amplifier Figure 16 Components of the Gas Control System Maxitrol Series 44 used in Gas Control Option AG33 Troa Temperature ji Sensor gn 119617 Ly Amplifier P N 157915 Temperature Selector P N 86990 En Mixing Tube P N 90323 Option AG36 is a special application gas train that is designed for controll
9. supply con nection to the burner The manifold selection ordered determines the manifold arrangement including all of the gas train components except the main control valve Manifold arrangements are available for varying BTUH ranges and gas controls and include versions that meet FM or IRI requirements In addition to the Maxitrol valve and two solenoid valves all manifold arrangements include main gas and pilot gas shut off cocks a pilot regulator and a pilot solenoid valve The table below lists the pressure drops through the various types of manifolds by option designation BM To determine the required mini mum supply pressure for natural gas add 5 0 w c to the natural gas manifold pressure drop For propane gas add 2 0 w c Figure 19 Gas Manifold Control Components Solenoid Valve Modulating Regulating Valve Manifold Pressure Drops w c Manifold Opt BM62 BM63 BM64 BM65 BM67 BM68 BMS53 BM66 Manifold Size 1 3 4 1 1 1 4 1 1 4 Paj 1 1 4 2 MBH Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro 250 56 WA 66 29 43 17 22 09 19 07 07 03 22 09 07 03 500 2 23 85 2 65 1 01 1 74 66 89 34 76 29 W 10 89 34 27 10 750 5 02 1 91 5 96 2 27 3 91 1 49 2 01 Td 1 71 65 61 23 2 01 ad 6 23 1000 6 95 2 65 3 58 1 36 3 04 1 16 1 09 41 3 58 1 36 1 09 41 1250 5 59 2 13 4 76 1
10. Air Control Options AR19 AR20 AR22 AR23 AR32 AR33 AR34 AR36 or AR37 Function With a bypass damper the volume of outside air supplied to the building is adjusted by a manually set potentiometer Option AR19 and AR22 or automatically by a pressure null switch Option AR20 or AR23 a photohelic pressure switch Option AR36 or AR37 Hot Surface Ignition System with Prepurge or a field supplied computer signal Option AR33 or AR34 With Time Delay and Flame Sensor with 100 Options ARIY AR20 AR33 and AR36 the supply air 1S varied by Lockout ere ce Teme Er epee ae peee a hears Function The ignition system including the controller the hot surface vary the volume of return air The unit is arranged so that a fixed amount ignitor and the flame sensor function to ignite and prove the pilot 20 of the rated volume flows over the burner at a constant velocity flame When there is a call for heat the modular ignition controller is The remainder 80 of the rated air volume flows either through a energized When the controller reads 1 4 amps going to the hot surface balancing bypass damper or a combination of bypass and return air ignitor it opens the pilot valve for a 15 second trial for ignition After dampers As the supply air volume is varied by the return air or dis the pilot flame rod senses pilot flame the main gas valve is energized If charge damper the balancing damper is adjusted to maintain the re the pilot flame rod d
11. MAINTENANCE SECTION Configuration Maintenance Schedule 1A Blower Bearings 1B Blower Belts 2 Filters 3 Manifold Gas Pressure 4 Air Pressure 5 Circuit Indicator Board check lights 4 6 Main Burner and Pilot Assembly OPERATION SERVICE SECTION Controls Location INDOOR OR OUTDOOR GAS DIRECT FIRED MAKEUP AIR TABLE OF CONTENTS Page 8 Temperature Limit Safety Controls 5 eManual Reset Limit Control Emergency Cut Off Limit Control 6 9 Air Pressure Switches eLow Air Flow Switch High Air Flow Switch Bypass Damper Optional Air Flow Switches 10 Ignition System 11 Gas Train Including Direct Fired Burner Gas Control Systems Manifold Arrangements and Gas Pressure Switches Direct Fired Burner Makeup Air Gas Control Systems 7 Electronic Modulation Gas Control Options AG30 AG31 AG32 HEATING SYSTEMS Specifications subject to change without notice Operation Maintenance Service Form RZ NA 441 OMS eManifold Arrangements Gas Pressure Switches Outside Air Ambient Cutoff Door Switch Inlet Air Controls Air Flow Dampers eDamper Motor Potentiometer Pressure Null Switch Photohelic Pressure Switch Dirty Filter Switch Photoelectric Smoke Detector Firestat Freezestat Troubleshooting 7 Electronic Circuit Board with Diagnostic Lights Option AG37 AG33 AG35 AG36 Electronic Modulation Gas Control Chart 1 General Troubleshooting
12. a Optional Optional Bypass Damper Standard Pressure Dirty Filter Switches Pressure Switches Pressure Switch WARNING Service work on this system should only be done by a qualified gas ser vice person The service information and the troubleshooting guides are intended as an aid to a qualified service person Time Delay Relay 24 volt Terminals Return Air Transformer Motor Starter Relay for Starter Line Voltage Optional 2 Speed Relay Terminals NOTE Wiring diagrams for the unit are located on the inside of the electrical box door 7 Electronic Circuit Board with Diagnostic Lights Location Control Compartment Electrical Box See Figure 7 Function The diagnostic lights on the circuit board are designed to assist in troubleshooting When the system is operating properly the lights on the circuit board are lit If the system fails to operate properly all lights on the circuit board up to that one that represents the component or system that has failed will be lit For more detailed information refer to the Trouble shooting Guide in Paragraph 19 Figure 8 Diagnostic Circuit Board P N 151263 T Column of 13 indicator bulbs always replace burned out bulbs P N 125189 ih th A r Ein free a a we oar a F F 0 a a T Ti J T fF ro w Ha e H tials a itunes Sas lt 7 s betwee ded 8 Temperature Limit Safety Controls
13. air damper As more pressure is required in the building the switch activates the damper motor driving the outside air damper towards the full open position causing the bypass return air damper to go toward the closed position Con versely as less pressure is required the switch drives the outside air damper in the opposite direction Figure 26 Photohelic Pressure Sensor Service Clean the tubing and the screened ends of the pressure tap vents If the interior of the switch is protected from dust dirt corrosive gases and fluids years of trouble free service may be expected Zero adjust ment should be checked and reset occasionally to maintain accuracy follow the manufacturer s instructions included with the switch There are no field repairable parts in this switch If the switch should require repair contact either the system or the switch manufacturer concerning switch replacement or repair 15 Dirty Filter Switch Location Switch is located in the main electrical box See Figure 7 sensor tubes run to either side of the filter rack indicator light is on the remote console Figure 27 Dirty Filter Pressure Switch P N 105507 Function The dirty filter switch is a pressure switch that activates an indicator light on the remote console when the filters need cleaned or replaced See Ser vice Section Paragraph 2 This switch is only on systems with an optional console that includes a dirty filter l
14. arings All blowers are Class I with pillow block bearings Clean the fitting and add type NLG 2 or 2 standard grade grease Add grease with a handgun until a slight bead of grease forms at the seal Be careful not to unseat the seal by over lubricating NOTE Ifunusual environmental conditions exist temperatures below 32 F or above 200 F moisture or contaminants more frequent lubri cation is required CAUTION If the blower is unused for more than three months the bearings should be purged with new grease prior to startup Recommended E Lubrication Schedule in Months Bearg Bore Diameter Bearing Bore Diameter Inches gt to gt 1 1 2 to to l 1 1 2 1 15 16 tso 6 J 6 6 501 1000 6 6 6 1B Blower Belts Check belts for proper tension and wear Adjust belt tension as needed Replace worn belts Proper belt tension is important to the long life of the belt and motor A loose belt will cause wear and slippage Too much tension will cause 3 Manifold Gas Pressure excessive motor and blower bearing wear If adjustment is required adjust belt tension by means of the adjusting screw on the motor base until the belt can be depressed 1 2 to 3 4 Figure 2 Tighten the lock nut on the adjusting screw Be sure the belt is aligned in the pulleys Figure 2 Belt Tension IR E 2 Filters If the system includes filters check the filters quarterly Filters could be either in the optional inlet
15. ature These modulating gas control options are electronic because in all cases the gas valve acts to adjust the flow of the gas to the main burner in response to DC volts emanating from an amplifier When the DC voltage is between 0 and 5 volts the main valve seat is closed Low fire flow is accomplished through a mechanical bypass The low fire flow rate is set at the factory and should not need adjustment However if adjustment is necessary refer to the Maxitrol literature that is included in the heater owner s enve lope All of the electronic modulating gas control burner systems in clude low fire start On an initial call for heat the main burner ignites at its lowest input During mild weather the burner may then cycle off Such full shutdown can be dictated by the outdoor ambient cutoff control As the outside air temperature climbs above the setpoint of the outdoor ambient control the burner control circuit is de energized When moderately cold outside air temperatures exist the burner will modulate between low flame and high flame Low fire start and the outdoor ambient control prevent the makeup air system from heating already warm air and providing too much heat to the building For troubleshooting guides and further explanation of Maxitrol Series 14 and 44 electronic modulation gas control systems refer to the Maxitrol literature in the owner s envelope The Option AG30 AG31 AG32 and AG35 electronic modulation systems
16. base or in an optional filter cabinet 3 4 19mm If the filters are in the perimeter of the inlet base they are two inch permanent filters Remove and clean the filters as needed If the filters are in a filter cabinet the filter cabinet is always between the inlet base and the burner control section remove the filter cabinet door panels to access the V bank filter rack Filters may be either 2 disposable 1 or 2 permanent or 1 or 2 disposable pleated Clean or replace as needed Sizes and Quantity of Filters in the Filter Cabinet same for all types of filters Size 109 112 115 16 x 16 4 16 x 20 4 lo x 23 Semiannually check the gas pressure to the burner and to the pilot Measure both manifold pressure and pilot supply pressure with the blower in operation Refer to Figure 3 for pressure tap locations Verify against pressures listed on the rating plate Figure 3 Location of pressure taps for measuring burner and pilot gas pressure Measure with blower operating Pilot Manifold Gas Supply Inlet Pressure Tap Pilot Regulator Pilot Solenoid Valve 4 Air Pressure Profile plate sensing tubes should be checked quarterly and cleaned no less than semiannually If the sensing tubes become even partially blocked false pressure readings may be relayed To clean remove the screened end caps Clean the screens and the tubes if necessary Re place the cleaned end caps Check the pressure differe
17. estat lights are lit but starter energized light is not lit and the blower motor is not operating 5 Disconnect closed blower switch in test position firestat freezestat and starter energized lights are lit but the blower motor is not operating 6 Disconnect closed blower switch in test position firestat freezestat and starter energized lights are lit and the blower motor is operating but the low air light is not lit 7 Disconnect closed blower switch in test position firestat freezestat starter energized and low air lights are lit and the blower motor is operating but the high air light is not lit 8 Disconnect closed blower switch in test position firestat freezestat starter energized low air and high air are lit but the limit control normal light is not lit 9 Disconnect closed blower switch in test position firestat freezestat starter energized low air high air and limit control normal lights are lit but the ambient outside air cutoff normal light is not lit 10 Disconnect closed blower switch in test position firestat freezestat starter energized low air high air limit control normal and ambient outside air cutoff normal lights are lit but the low gas pressure normal light is not lit 11 Disconnect closed blower switch in test position firestat freezestat starter energized low air high air l
18. estat will shut down the system if the temperature in the ductwork reaches 200 F The switch must be manually reset Service Clean the external surface Check the wiring and connections 18 Freezestat Option BE2 Location The control is in the blower section electrical box the sensing bulb is field mounted in the discharge duct Figure 30 Freezestat Controller P N 126170 Function The freezestat will shut down the system if the discharge temperature falls below the setpoint The switch is automatic and will startup the heater when the temperature reaches the setpoint Service Clean the external surface Check the wiring and connections REFERENCE For service and troubleshooting information on the electrical controls refer to the manufacturer s literature covering that component Component literature is included in the literature envelope shipped with the system Refer to Paragraph 19 for unit troubleshooting Page 10 19 Troubleshooting Chart 1 General Troubleshooting Guide Check the diagnostic lights on the circuit board Symptom or Problem Cause and Remedy 1 Disconnect switch is closed but control power light is not lit 2 Disconnect switch is closed but firestat normal light is not lit 3 Disconnect closed blower switch in test position firestat light is lit but freezestat light is not lit 4 Disconnect closed blower switch in test position firestat and freez
19. fixed amount of air volume flows over the burner Option AR37 a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers The volume of outside air is regulated by a remotely located photohelic pressure sensor Air Flow Dampers Function Dampers operate in response to controls to provide the rated flow of makeup air to the building Service Clean dampers of dust or dirt Damper Motor Function The damper motor automatically ac tuates the return air bypass and or discharge dampers in response to an electrical control de lt vice The damper motor is direct coupled to the dampers so there is no damper linkage to ad just Service There is no service required on these motors other than external cleaning If the mo tors need replaced replace with an identical damper motor Potentiometer Function The potentiometer is a manually set switch that operates either the discharge damper Option AR19 or the return air damper Op tion AR22 providing a mixture of return and outside air It is a remotely located switch that requires manual adjustment Service If the potentiometer does not func tion properly replace it with an identical switch Pressure Null Switch automatic building pressure sensor Description Function The pressure null switch is a diaphragm operated differ ential pressure switch used in makeup air applications to automatically control Figure
20. ight The pressure switch is set during installation so that the light will be activated at approximately 50 filter blockage Contacts should close at 17 to 5 0 w c 05 w c Service Clean the sensor tubes If the dirty filter indicator system still does not function properly check the setting of the switch With clean filters in place blower doors closed and blower in operation decrease the pressure setting by adjusting the set screw on the switch clockwise until the filter light is energized or screw is bottomed out At that point adjust the set screw three full turns counterclockwise or until the screw is top ended If it is determined that the switch needs replacing use an identical switch When a new switch is installed it must be manually set follow the instructions above 16 Photoelectric Smoke Detector Option SA1 Location Field mounted in Figure 28 Photoelectric Smoke the discharge ductwork Detector cover removed P N Function The detector will 159553 used with sampling tube shut down the system if P N 159714 smoke is detected in the dis I a charge ductwork H cin Service Clean the external surface Check the wiring and connections 17 Firestat Option BD5 Location Field mounted on the dis charge ductwork so that the sensor extends into the duct This control requires manual reset so should be mounted in an accessible location Figure 29 Firestat P N 42782 Function The fir
21. imit controls normal ambient outside air cutoff normal and low gas pressure normal lights are lit but the high gas pressure normal light is not lit 12 Disconnect closed blower and burner switches in run position control switch is in winter position control power high gas normal low gas normal firestat normal system switch energized starter energized and freezestat normal lights are lit but ignitor is not becoming energized or beginning to glow 13 Disconnect closed blower and burner switches in run position control switch is in winter position control power high gas normal low gas normal firestat normal system switch energized starter energized and freezestat normal lights are lit ignitor glowing but pilot valve normal light thus the pilot valve is not energized WN eJ NO RIP B WN RIL W N RL W N RIL W N eJ NH RT BR amp RIN nN BW N FTN BW Ne Fuses are missing or blown in disconnect switch replace fuses Transformer not wired according to diagram check wiring Secondary 8A fuse on transformer is missing or blown replace fuse Indicator light is burned out replace bulb P N 125189 See causes and remedies for Problem 1 above Optional control relay or door switch contacts are open to test jump terminals 3 to 4 or 1 to 2 Firestat option not ordered verify order wiring diagram Firestat manual reset tripped reset fires
22. ing the environment of a paint booth operation The system includes a Maxitrol A1494 amplifier discharge air temperature sensor dual remote discharge air temperature selector drying selector 80 140 F and a spray selector 60 90 F and two switches to control the operation of the modulating gas valve Figure 17 Components of the Gas Control System used in Option AG36 designed specifically for paint booths controls are mounted on a remote console Selector Amplifier P N P N 133229 133230 Electronic Modulation Gas Control Option AG37 Function Control Option AG37 does not have a duct sensor or ampli fier Instead a Maxitrol A200 signal conditioner is activated by a cus tomer supplied input signal either 4 20 milliamps or 0 10 volt to control the modulation of the gas valve Figure 18 Maxitrol A200 Signal Conditioner P N 134170 used in Gas Control Option AG37 11 Gas Train Including Direct Fired Burner Gas Control Systems and Manifold Arrangements cont d Service All Maxitrol Controls Check all electrical connec tions A qualified service person should refer to the Maxitrol Trouble shooting Guides for assistance in identifying problems and determining the correct solution None of the Maxitrol controls have field replace able parts All components must be replaced with identical replacement parts Manifold Arrangements Description The manifold is the gas train from the gas
23. iting device and do not require venting to the outdoors when used in an application installed indoors Page 8 12 Outside Air Cutoff Control Option BN2 required on C G A certified units Location The control is in the electrical box See Figure 7 the sensor is in the air inlet Figure 21 Outside Air Function After sensing pilot flame the Cutoff Control burner ignites at its lowest input rate The amount of heat required to reach the de sired discharge temperature also depends on the temperature of the incoming outside air The outside air control is factory set at 60 F adjustable 25 250 F The burner reacts differently depending on the entering air tem perature and the setting on the outside air control The burner e may not ignite pilot valve will not open If the actual temperature of the outside air is above the setpoint on the outside air control the burner will not ignite e may modulate to satisfy discharge setting e may shutdown or Burner shutdown or modulating operation will depend on the tem perature rise between the outside air and the discharge air setting e may remain on continuous low fire If the outside air control is set too high the burner will continuously burn on low fire as long as the control switch is set to winter When the outside air control is set properly for the climate the system blower will continue to provide the required makeup air ventilation at the ambie
24. makeup air Option AR19 100 outside makeup air with variable supply air volume CFM The discharge damper controlling the variable air sup ply is controlled by a manually set remote potentiometer and can be varied from 100 to 20 of total rated air flow CFM In response to changes in the discharge damper setting the bypass damper balances the volume of air so that the required fixed amount of air volume flows over the burner Option AR20 100 outside makeup air with variable supply air volume CFM The discharge damper controlling the variable air sup ply is automatically controlled by a building pressure sensor and can be varied from 100 to 20 of total rated air flow CFM In response to changes in the discharge damper setting the bypass damper balances the volume of air so that the required fixed amount of air volume flows over the burner Option AR22 a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers The volume of outside air is regulated by a remotely located manually set potentiometer Option AR23 a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers The volume of outside air is regulated automatically by a remotely located building pressure sensor Option AR32 a combination of outside makeup air and bypass return air including a two position actuator The two position actuator changes the po
25. metal fasteners may be difficult to remove Be careful not to damage the gaskets that go between the mixing plates and the burner body The gaskets are designed to overlap approximately 1 16 for tight air seal Follow Steps in reverse order to re install the pilot assembly Close all panels and check for proper operation _ Figure 6 Illustration of the first Burner Section Full length of the burner is made up ofa series of 6 or 12 burner sections ina linear or oval configuration Burner WARNING Burner profile plates are factory set to match CFM requirements Do not adjust profile plates without contacting your Sales Representative for technical assistance Operation Service Section Controls Location Operation and Service To service this system it is necessary to understand the normal operation of the controls and the function of the diagnostic circuit board Refer to the electrical box drawing in Figure 7 and to the individual illustrations to identify and locate each of the controls The wiring diagrams for this unit are located in the main electrical box Figure 7 Control Locations Control Outside Air Cutoff high ambient limit control Ignition LL abode bod auaua i Status Lights CLE emt ooo0oo0o000000000 Maxitrol Amplifier or Signal Conditione Circuit g Service Board Switches i l Ni TESS G SS e F o pm z z 5 aA wt N icin a
26. nt outdoor temperature burner not operating even when the control switch is set to winter Service If the control does not function properly replace it with an identical switch 13 Door Switch Option BX1 required on C G A certified units Location The control is installed on an over head door opening to control the operation of the heater to coincide with the opening and clos ing of the door Function The function of the switch is to ener gize and interlock the heating unit when an out side overhead door reaches approximately 80 of full open travel The switch will de energize the furnace when the overhead door closes ap proximately 20 The complete switch includes a limit switch electrically wired to the heater and a roller yoke for mechanical activation by a field supplied trigger on the overhead door 14 Inlet Air Controls WARNING Burner profile plates are factory set to match CFM requirements Do not adjust profile plates without contacting your Sales Representative for technical assistance Figure 22 Door Switch P N 124253 Description The system is equipped with one of the 11 types of inlet air control arrangements listed below All systems provide a con stant flow of outside air across the burner at the required air volume CFM Refer to the wiring diagrams in the main electrical box to determine which controls are on the system being serviced QOption AR1 a constant supply of 100
27. ntial across the profile plate using a slope gauge Air pressure differential should be between 5 and 7 w c To attach the slope gauge open the control compartment door panel Just below the junction box locate the tubing connections Remove the cap at each connection and attach the slope gauge using two field supplied 1 4 x 1 8 female NPT barbed tubing connections For in structions on measuring air pressure see Service Section Paragraph 9 5 Circuit Indicator Board check lights The circuit indicator board is located in the control compartment elec trical box See Figure 7 Check operation of all indicator lights by switching lights that are not lit with one that is currently lit Replace all burned out indicator bulbs P N 125189 Figure 4 Circuit Indicator Board P N 151263 Row of Bulbs Check bulbs not lit with other bulbs replace any burned out bulbs 9 92 22 oo ps 6 Main Burner and Pilot Assembly For the most part the burner and pilot are self cleaning However if the application is extremely dirty or dusty cleaning of the burner and pilot may be necessary Inspect the burner annually Follow these instruc tions If it is necessary to replace any parts use only factory autho rized replacements 1 Turn off the gas and power supply to the system 2 Remove the door panels in the burner control cabinet four or six depending on whether or not the system has return air Locate the pilot 3
28. ntrol system The velocity of air is controlled by the profile plates and monitored by a standard low and high air pres sure switch Service Refer to Paragraph 6 in the Maintenance Section for instructions on burner maintenance WARNING Burner profile plates are factory set to match CFM requirements Do not adjust profile plates without contacting your Sales Representative for technical assistance Makeup Air Gas Control Systems e Electronic Modulation Gas Control Options AG30 AG31 AG32 AG33 AG35 AG36 Refer to the wiring diagrams in the main electrical box to deter mine which controls are on the system being serviced NOTE All field supplied control wiring for Maxitrol controls must not be run inside conduit with line voltage wiring To avoid any potential electrical interference all field supplied wiring for Maxitrol con trols should be shielded wiring and must be grounded at the unit only Function These makeup air gas control systems provide heated makeup air at a temperature controlled by a discharge air sensor Each system is equipped with electronic modulation controls that modulate burner flame from 1 25th of full fire input to full fire The electronic modulating type gas controls act in response to discharge and or room air temperature sensors to change the gas flow rate to the burner thus lengthening or shortening the flame The BTU output is varied modulated to maintain the required discharge air temper
29. oes not sense a pilot flame the controller shuts quired air velocity over the burner Adjustment of the bypass damper is down the pilot valve fora 10 second interpurge and then opens it again controlled by the bypass damper pressure switches One pressure for a second ignition trial If pilot flame is not proven on the second switch is normally closed with a setting of 5 w c the other is nor trial the ignition controller locks out and must be manually reset by an mally open with a setting of 65 w c balancing bypass damper interruption of the main circuit disconnect switch Sensing Pressure Check requires a slope gauge several feet of Service The modular ignition controller does an internal self check 1 4 oo tubing and two 1 4 O D barbed tees each time that it is energized and will lockout if not found to be func Page Figure 13 Ignition Control Figure 14 Ignitor P N Module in the Electrical 121865 and Flame Sensor P N 134706 on the Burner Sensor tioning properly If the ignition controller locks out and there is no other cause the controller module must be replaced 11 Gas Train Including Direct Fired Burner Gas Control Systems Manifold Arrange ments and Gas Pressure Switches Direct Fired Burner Function The design of the direct fired burner and the con trolled velocity of air at the burner ensure complete combustion through the full range of burner sizes and gas inputs as determined by the gas co
30. sition of the damper to provide either 100 outside air or 20 outside 80 return air Control is from a SPDT toggle switch mounted on a 4x4 box or if ordered the switch is mounted on a remote console Option AR33 100 outside makeup air with variable supply air volume CFM The discharge damper controlling the variable air sup ply is automatically controlled by a 0 10 VCD or 4 20 milliamp signal In response to changes in the discharge damper setting the bypass damper balances the volume of air so that the required fixed amount of air volume flows over the burner Option AR34 a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers The volume of outside air is regulated by a 0 10 VCD or 4 20 milliamp signal Option AR35 a constant supply of 100 makeup air to the unit but including a two position inlet shutoff damper that closes the dampers when the system is not operating The damper attaches to the duct flange of the optional inlet base used only with the optional inlet base that has three closed sides and a duct connection for outside air Option AR36 100 outside makeup air with variable supply air volume CFM The discharge damper controlling the variable air sup ply is automatically controlled by a remotely located photohelic pres sure sensor In response to changes in the discharge damper setting the bypass damper balances the volume of air so that the required
31. switches in run position Faulty main gas valve replace main gas valve control switch is in winter position all status lights are lit the Inadequate timing on high fire time delay relay adjust setting pilot flame and low fire on the main burner are present and stable Faulty high fire time delay relay replace time delay relay but the unit will not progress to a high fire condition High stage relay contacts are not closed check control setting Inadequate main gas pressure verify main burner gas pressure Faulty high stage relay replace relay YAN nN PWN KH Tn A U N Faulty ignition module replace entire module FOR SERVICE OR REPAIR FOLLOW THESE STEPS IN ORDER Contact the Installer Name Address Phone SECOND Contact the nearest distributor See Yellow Pages If no listing contact Authorized Factory Representative 1 800 695 1901 Press 1 THIRD Contact REZNOR Thomas amp Betts Corporation 150 McKinley Avenue Mercer PA 16137 Phone 724 662 4400 Model No Unit Serial No Date of Installation Index Air Pressure Filters Manifold Arrangements Air Pressure Switches Firestat Operation Service Section Blower Bearings Freezestat Outside Air Cutoff Control Circuit Indicator Board Gas Control Systems Photoelectric Smoke Detector Control Locations Gas Pressure Photohelic Pressure Sensor Damper Motor Gas Pressure Switches Pilot Assembly Direct Fired Burner Inlet Air Controls Potentiometer
32. t protection hose connections against overheating If the temperature sensitive limit control malfunctions the electrically activated emergency cutoff will shutdown the system Limit Control P N 82414 A If the system includes an optional discharge damper before measur ing burner differential air pressure check to be sure that the damper is fully open B With the blower operating the pressure differential on the slope Service If this limit activates the manual gauge should read between 5 and 7 w c If the slope gauge limit control has failed and must be re Setting 305 F reading is within those limits no adjustments are necessary placed The cause for activating the emer If the slope gauge reading is not within the setpoint limits of the air gency cut off limit control must be found and corrected before re flow switches 2 to 9 w c and the system is operating replace starting the system the air pressure switch es 9 Air Pressure Switches If the slope gauge reading is not between 5 and 7 w c but within the setpoint limits clean the sensing tubes Follow the in structions in Maintenance Section Paragraph 4 Location Control Compartment Electrical Box See Figure 7 Depending on the options selected there are two or four switches Oo C When air pressure is within the proper range turn the disconnect switch OFF Disconnect the manometer and the slope gauge Re place the caps removed to connec
33. t the slope gauge Figure 12 Air Pressure Switch Service Ifthe pressure check determines that an air flow switch is not functioning properly the switch cannot be serviced and must be re placed with an identical replacement Low air pressure switch is P N 86986 high air pressure switch is P N 86987 bypass damper switches P N 87249 normally closed set to open at 5 w c or P N 87250 normally open set to close at 65 w c e Low Air Flow Switch 10 Ignition System Function The low air flow switch is a velocity Bee switch that Location Ignition Controller Module in the Control Compartment monitors air flow across the burner Until the air flow attains adequate Electrical Box See Figures 7 and 13 Ignitor and Flame Sensor on the volume for combustion the switch remains open When the switch Burner See Figure 14 recognizes adequate air volume it closes permitting both the pilot and burner to operate Low pressure switch is normally open it closes on pressure rise at 2 w c Do not alter or adjust setting e High Air Flow Switch Function The high air flow switch is a velocity pressure switch that monitors air flow across the burner If the high air flow switch senses air velocity above the prescribed limit it will shutdown gas flow to the burner High pressure switch is normally closed it opens when pres sure rises above 9 w c Do not alter or adjust setting e Bypass Damper Air Flow Switches systems with
34. tat control Freezestat option not ordered verify order wiring diagram Freezestat relay contacts are open checking setting on control Indicator bulb is burned out replace bulb P N 125189 End switch on damper motor not closed check end switch wiring Faulty damper relay replace relay Damper motor miswired rewire damper motor per wiring diagram Blower motor not wired correctly check wiring diagram on motor Faulty motor starter replace check coil first Faulty blower motor relay replace relay Low air switch open verify pressure drop at burner Indicator light is burned out replace bulb P N 125189 Faulty low air switch replace pressure switch P N 86986 High air switch open verify pressure drop at burner Indicator light is burned out replace bulb P N 125189 High air switch option not ordered verify order wiring diagram Faulty high air switch replace pressure switch P N 86987 Indicator light is burned out replace bulb P N 125189 Tripped manual reset limit control s reset manual control Faulty manual limit control s replace limit control Indicator light is burned out replace bulb P N 125189 High ambient control option not ordered verify order wiring diagram High ambient control contacts open check setting on control Indicator light is burned out replace bulb P N 125189 Low gas pressure switch op
35. the installation does not permit the burner to receive the proper supply of combustion air complete combustion may not occur The result is incomplete combustion which produces carbon monoxide a poisonous gas that can cause death Always comply with the combustion air requirements in the installation codes and operating instructions The amount of air over the burner must be within the specified range The burner profile plates are set at the factory to match CFM requirements Do not adjust the burner profile plates without contacting the factory FAILURE TO PROVIDE PROPER COMBUSTION AIR CAN RESULT IN A HEALTH HAZARD WHICH CAN CAUSE PROPERTY DAMAGE SERIOUS INJURY AND OR DEATH Direct fired installations should provide for air changes as required by the applicable installation codes Maintenance Section This direct fired makeup air system is designed to require only a minimum amount of maintenance Some maintenance procedures outlined in this Section WARNING Disconnect all power to the system before doing any maintenance require inspection only and some require action Frequency requirements of Failure to do so may cause electrical shock each maintenance procedure are listed in the Maintenance Schedule Depending personal injury or death on the environment and the number of operating hours more frequent inspec tion and or cleaning may be required to certain components M a i nte nance S C h ed u le Although maintenance req
36. tion not ordered verify order wiring diagram Low gas pressure switch contacts open check setting on control Low gas pressure switch contacts open check gas pressure Faulty gas pressure switch replace gas pressure switch Indicator light is burned out replace bulb P N 125189 High gas pressure switch option not ordered verify order wiring diagram High gas pressure switch contacts open check setting on control High gas pressure switch contacts open check gas pressure Manual reset on switch tripped reset pressure switch manual reset Faulty gas pressure switch replace gas pressure switch Lack of power at L1 on ignition module ECO blown find cause then replace ECO 2 Faulty burner enable relay replace relay Low stage relay contacts are not closed check air controller or thermostat setting 4 Faulty low stage relay replace relay Faulty hot surface ignitor check continuity at the ignition module and circuit board If reading is greater than 5 6 ohms replace ignitor Faulty ignition module replace entire module Ignitor not reaching 1 4A threshold check voltage and current to ignitor Faulty hot surface ignitor check continuity rep lace ignitor Faulty ignition module replace entire module Page 11 19 Troubleshooting cont d Chart 1 cont d General Troubleshooting Guide Check the diagnostic lights Symptom or Problem cont d
37. uirements are minimal the routine maintenance pro cedures in this Section are necessary to ensure safe reliable and or efficient See Chart Cl Lubricate bearings Paragraph 1 operation The paragraphs which follow discuss the components and systems that require routine inspection maintenance At the beginning ofeach paragraph Quarterly ClCheck the filters Paragraph 2 there is a code indicating why that maintenance procedure is necessary The legend for that code is shown below Check air pressure sensing tubes Paragraph 4 Maintenance Codes Semi Annually LJCheck blower belts Paragraph 1 Season or praunbenance Cl verify gas pressures Paragraph 3 S Safety to avoid personal injury and or property damage Cl Clean air pressure sensing tubes Paragraph 4 R Continued Reliability as CCheck indicator lights Paragraph 5 E Efficient Operation Annually C Check main burner and pilot assembly Paragraph 6 Figure 1 System Configuration Blower Section Discharge Air Location of Optional Filter Cabinet not shown Screened Inlet Base Page 2 r 1 Drive Components The blower motor and drive components are located in the blower cabinet at the top of the system Systems with horizontal discharge have a cabinet with eight removable door panels Systems with vertical discharge have a cabinet with six removable door panels Remove the panels required to access the components being serviced 1A Blower Be
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