SERVICING
34
Table of Contents
HIGH VOLTAGE!
Disconnect ALL power before servicing or installing this unit. Multiple power sources
may be present. Failure to do so may cause property damage, personal injury or death.
S-1
Checking Voltage .......................................... 35
S-2
Checking Wiring ............................................ 36
S-3
Checking Thermostat, Wiring & Anticipator .. 36
S-3A
Thermostat & Wiring ..................................... 36
S-3B
Cooling Anticipator ........................................ 36
S-3C
Heating Anticipator ........................................ 36
S-4
Checking Transformer & Control Circuit ....... 37
S-7
Checking Contactor and/or Relays ................ 37
S-8
Checking Contactor Contacts ....................... 37
S-9
Checking Fan Relay Contact ........................ 38
S-12
Checking High Pressure Control ................... 38
S-13
Checking Low Pressure Control .................... 38
S-15
Checking Capacitor ....................................... 38
S-15A Resistance Check ......................................... 39
S-15B Capacitance Check ....................................... 39
S-16A Checking Fan & Blower Motor
Windings (PSC Motors) ............................... 40
S-16C Checking ECM Motor Windings .................... 40
S-16D Checking GE X13™ Motors .......................... 40
S-17
Checking Compressor Windings ................... 41
S-17A Resistance Test ............................................ 41
S-17B Ground Test .................................................. 42
S-17C Unloader Test ................................................ 42
S-17D Operation Test .............................................. 43
S-18
Testing Crankcase Heater (optional item) ..... 43
S-100
Refrigeration Repair Practice ......................... 43
S-101
Leak Testing ................................................. 44
S-102
Evacuation .................................................... 44
S-103
Charging ........................................................ 45
S-104
Checking Compressor Efficiency .................. 45
S-105B Thermostatic Expansion Valve ...................... 45
S-106
Overfeeding ................................................... 47
S-107
Underfeeding ................................................. 47
S-108
Superheat ..................................................... 47
S-109
Checking Subcooling .................................... 49
S-110
Checking Expansion Valve Operation ........... 49
S-111
Fixed Orifice Restriction Devices .................. 49
S-112
Checking Restricted Liquid Line .................... 50
S-113
Refrigerant Overcharge .................................. 50
S-114
Non-condensables ........................................ 50
S-115
Compressor Burnout ..................................... 50
S-200
Checking Extedrnal Static Pressure ............. 51
S-201
Checking Temperature Rise .......................... 51
S-300
Testing Primary Limit .................................... 52
S-301
Testing Auxiliary Limit ................................... 52
S-302
Checking Flame Rollout Switch .................... 53
S-303
Testing Inducer Motor .................................... 54
S-304
Testing Gas Valve ......................................... 54
S-305
Checking Main Burners ................................. 55
S-306
Checking Orifices .......................................... 55
S-307
Checking Gas Pressure ................................ 55
S-308
Checking For Delayed Ignition ...................... 57
S-309
Checking for Flashback ................................. 57
S-310
Checking Pressure Control ........................... 57
S-311
High Altitude Application ............................... 58
S-313
Testing Ignition Control Module ..................... 58
S-314
Checking Flame Sensor ................................ 61