CONQUEST 80 - Page 4

Page Number
SERVICE AND TROUBLESHOOTING ......................................................................................55
Introduction ......................................................................................................................55
Test equipment ................................................................................................................55
INSTALLATION AND SERVICE CHECKLIST ...........................................................................56
ROBERTSHAW AND HONEYWELL STANDING PILOT FAN CONTROL BOARDS ...............58
STANDING PILOT TROUBLESHOOTING GUIDE ....................................................................59
ACCESSORY BOARD ...............................................................................................................60
FAN CONTROL BOARD RESPONSES .....................................................................................61
INTEGRATED FURNACE CONTROL (IFC) ..............................................................................61
UNITED TECHNOLOGIES (UTEC) ...........................................................................................62
Lock out status ................................................................................................................62
Soft lock out causes ........................................................................................................62
Hard lock out causes .......................................................................................................62
Self healing ......................................................................................................................62
Low thermostat anticipation .............................................................................................63
Control board characteristics ...........................................................................................63
Control responses ...........................................................................................................64
HONEYWELL .............................................................................................................................65
Lock out status ................................................................................................................65
Soft lock out causes ........................................................................................................65
Hard lock out causes .......................................................................................................65
Control board characteristics ...........................................................................................65
Control responses ...........................................................................................................65
Setting blower off controls ...............................................................................................66
Blower wiring connections ...............................................................................................67
Field installed accessories ..............................................................................................67
FLAME SENSING CURRENT SWITCH BOX ASSEMBLY .......................................................67
Switch box operation .......................................................................................................67
Reasons for burner lock out ............................................................................................68
REMOTE FLAME SENSOR KIT INSTALLATION ......................................................................68
Sensor mounting .............................................................................................................69
Sensor splicing ................................................................................................................70
REMOTE FLAME SENSING ROD .............................................................................................72
Reasons for burner lock out ............................................................................................73
INTEGRATED FURNACE CONTROL BOARD REPLACEMENT KIT .......................................73
Normal installations .........................................................................................................73
Remote flame sensor installation .................................................................................... 7 4
Twinned installations .......................................................................................................74
Fossil fuel kits ..................................................................................................................75
Twinned units with fossil fuel kits ....................................................................................75
PRESENT CONTROL DESCRIPTIONS AND TROUBLESHOOTING ......................................75
Integrated furnace controls used on current low profile gas furnaces .............................75
UTEC and Honeywell controls ........................................................................................75
Setting the blower off timings ..........................................................................................76
UTEC 1012-925 controls .................................................................................................
78
Integrated furnace controls used on current low profile gas furnaces .............................80
IFC troubleshooting guide ...............................................................................................82
Control responses ...........................................................................................................88
MAINPOWER "J" BOX ..............................................................................................................89
BLOWER DOOR SWITCH .........................................................................................................89
CONTROLS ................................................................................................................................89
NEGATIVE PRESSURE SWITCH .............................................................................................89
HIGH LIMIT CONTROL ..............................................................................................................90
HEAT ASSISTED LIMIT CONTROL (HALC) .............................................................................91
OVER TEMPERATURE SWITCH ..............................................................................................91
VENT SAFETY SWITCH ............................................................................................................92
TRANSFORMER ........................................................................................................................93
BLOWER MOTOR ......................................................................................................................93
INDUCED DRAFT BLOWER ASSEMBLY .................................................................................93
FURNACE GAS TRAIN ..............................................................................................................95
Gas valve .........................................................................................................................95
Adjusting gas pressure ....................................................................................................95
FURNACE ORIFICE SIZING ......................................................................................................97
CHECKING FURNACE INPUT ..................................................................................................97
HOT SURFACE IGNITE RS ........................................................................................................98
DIRECT SPARK IGNITERS .......................................................................................................98
STANDING PILOT BURNER .....................................................................................................99
AIR FLOW ..................................................................................................................................99
CO AND CO2 LEVELS IN FLUE GASES .................................................................................100
FLUE GAS TEMPERATURE RANGE......................................................................................100
WIRING DIAGRAMS ................................................................................................................101
SERVICE ANALYZER CHARTS .............................................................................................. 118
REVIEW QUESTIONS ............................................................................................................. 122
INDEX....................................................................................................................................... 124
INDEX OF FIGURES ................................................................................................................ 126
INDEX OFTABLES .................................................................................................................. 127
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