Method 2 - Trane Foundation GBC Series Installation, Operation And Maintenance Manual

After approximately 30 seconds, turn the "Mode"
selection switch to the desired mode, i.e. Heat, Cool or
Auto.
Table 15. Troubleshooting chart
Symptom
Unit will not run
Condenser fan runs, compressor
doesn't
Insufficient cooling
Compressor short cycles
Compressor operates
continuously
Registers sweat
High head-low vapor pressure
High head-high or normal vapor
pressure - Cooling mode
Low head-high vapor pressures
RT-SVX069A-EN
Possible Cause
Power off or loose electrical connection
Thermostat out of calibration-set too high
Failed contactor
Blown fuses
Transformer defective
Interconnecting low voltage wiring damaged
Run or start capacitor failed (single phase only)
Loose connection
Compressor stuck, grounded or open motor
winding open internal overload
Low voltage condition
Improperly sized unit
Improper airflow
Incorrect refrigerant charge
Air, non-condensible or moisture in system
Incorrect voltage
Incorrect voltage
Defective overload protector
Refrigerant undercharge
Dirty air filter
Unit undersized for load
Thermostat temperature set too low
Low refrigerant charge
Air in system
Outdoor coil dirty or restricted
Low evaporator airflow
Restriction in liquid line, expansion device or filter
drier
Flow check piston size too small
Incorrect capillary tubes
TXV does not open
Dirty condenser coil
Refrigerant overcharge
Condenser fan not running
Air or non-condensible in system
Defective compressor valves
Incorrect capillary tubes

Method 2

To reset the system at the unit, cycle the unit power by
turning the disconnect switch "Off" and then "On".
Check for correct voltage at compressor contactor in
control box
Reset
Check for 24 volts at contactor coil - replace if contacts are
open
Replace fuses
Check wiring - replace transformer
Replace thermostat wiring
Replace
Check for correct voltage at compressor - check and
tighten all connection
Wait at least 2 hours for overload to reset. If still open,
replace the compressor.
Determine cause and correct. At compressor terminals,
voltages must be within 10% of rating plate volts when
unit is operating.
Recalculate load
Check - should be approximately 400 CFM per ton.
Charge per procedure attached to unit service panel.
Recover refrigerant, evacuate & recharge, add filter drier
Determine cause and correct. At compressor terminals,
voltages must be within 10% of rating plate volts when
unit is operating.
At compressor terminals, voltage must be ±10% or
nameplate marking when unit is operating.
Replace - check for correct voltage
Add refrigerant
Replace filter
Decrease load or increase unit size
Reset thermostat
Locate leak, repair, and recharge
Recover refrigerant, evacuate system, and recharge
Clean coil or remove restriction
Increase speed of blower or reduce restriction - replace air
filter
Remove or replace defective component
Change to correct size piston
Change coil assembly
Replace TXV
Clean coil
Correct system charge
Repair or replace
Recover refrigerant, evacuate & recharge
Replace compressor
Replace coil assembly
T T r r o o u u b b l l e e s s h h o o o o t t i i n n g g
Remedy
35