GPH16M Installation Manual

16
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.
TROUBLESHOOTING CHART
SYMPTOM
High head - low suction a. Restriction in liquid line or
TXV not functioning
a. Remove or replace with proper size TXV.
High head - high or normal suction a. In Cooling: Dirty condenser coil a. Clean coil
In Heating: Dirty filter, Dirty indoor coil
b. Overchar
g
ed b. Correct S
y
stem char
g
e
c. In Cooling: Condenser fan not running
c. In Heating: Indoor blower not running c. Repair or Replace
a. Incorrect TXV. a. Replace with correct TXV
b. Defective compressor valves b. Replace compressor
c. TXV not functioning properly c. Check for debris in TXV or deform ed TXV.
Remove debris or replace TXV.
d. Incorrect TXV setting d. Check Super Heat
a. Power off or loose electrical
connection
a. Check for unit voltage at contactor in unit
b. Therm os tat out of calibration set too b. Res et
c. Defective contactor c. Check for 24 volts at contactor coil replace if
contacts are open
d. Blown fuses or tripped breaker d. Replace fuse or reset breaker
e. Transformer defective
e. Check wiring - replace transformer
f. High or low pressure control open
(Optional)
f. Check high pressure control or check unit
charge
High pressure control opens at 610 psig
Low pressure control opens at 22 psig
g. Compressor overload contacts open g. Replace compressor
NOTE: Wait at least 2 hours for overload to
Condenser fan runs,
compressor doesn't
a. Loose connection a. Check for unit voltage at compressor check &
tighten all connections
b. Compressor stuck, grounded or open
winding open internal overload
b. Wait at leas t 2 hours for overload to res et If
still open, replace the compressor.
c. Low voltage connection c. At compressor terminals, voltage must be
10 % of nameplate volts when unit is
d. Capacitor weak, open, or shorted d. Check capacitor. If defective, replace.
Low suction - cool compressor a. In Cooling: Low indoor airflow a.
Iced evaporator coil In Heating: Dirty outdoor coil, defective
defrost therm os tat, defective defrost
control board, outdoor fan not running,
low refrigerant charge.
b. Low airflow b. Check - should be approximatel
y
400 CFM per
ton, dirty air filters, all duct outlets open
c. Low refrigerant charge c. Properly charge unit
d. Operating unit in cooling mode below
65°F outdoor temperature
d. Install or check low ambient control, should
be open below 65°F outdoor temperature
a. Defective overload protector a. Replace - check for correct voltage
b. Unit cycling on low pressure control b. Check refrigerant charge and / or airflow
c. High pressure switch cuts out c. Check airflow (indoor & outdoor),
check expansion device
a. a. Increase speed of blower or reduce restriction
replace air filters
a. Excessive load a. Recheck load calculation
b. Defective compressor b. Replace
c. Reversing valve not seating properly. c. Replace
a. Improperly sized unit a. Recalculate load
b. Improper airflow b. Check - should be approximatel
y
400 CFM per
ton
c. Incorrect refrigerant charge. c. Charge per procedure attached to unit service
panel
d. Incorrect voltage d. At compress or term inals, voltage m us t be
within 10% of nameplate volts when unit is
operating
Increase speed of blower or reduce restriction
- replace air filters
Insufficient cooling
High suction pressure
REMEDYPOSSIBLE CAUSE
Compressor short cycles
Registers sweat Low airflow
Low head - high suction
Unit will not run