GPH16M Service Manual

SERVICING
41
SUBCOOLING = SAT. LIQUID TEMP. - LIQUID LINE TEMP.
Liquid
Pressure
Saturated Liquid
Temperature °F
PSIG R-410A
200 70
210 73
220 76
225 78
235 80
245 83
255 85
265 88
275 90
285 92
295 95
305 97
325 101
355 108
375 112
405 118
SATURATED LIQUID PRESSURE
TEMPERATURE CHART
SUBCOOLING = SAT. LIQUID TEMP. - LIQUID LINE TEMP.
Heat Pump - Heating Cycle
The proper method of charging a heat pump in the heat mode
is by weighing the charge according to the total charge listed
on the rating plate.
S-112 CHECKING RESTRICTED LIQUID LINE
When the system is operating, the liquid line is warm to the
touch. If the liquid line is restricted, a definite temperature
drop will be noticed at the point of restriction. In severe cases,
frost will form at the restriction and extend down the line in the
direction of the flow.
Discharge and suction pressures will be low, giving the ap-
pearance of an undercharged unit. However, the unit will have
normal to high subcooling.
If a restriction is located, replace the restricted part, replace
drier, evacuate and recharge.
S-113 REFRIGERANT OVERCHARGE
An overcharge of refrigerant is normally indicated by exces-
sively high head pressure and/or liquid refrigerant return to the
compressor.
If high head pressure is not indicated, an overcharge or a sys-
tem containing non-condensables could be the problem.
If overcharging is indicated:
1. Start the system.
2. Remove small quantities of gas from the suction line dill
valve until the head pressure is reduced to normal.
3. Observe the system while running a cooling performance
test, if a shortage of refrigerant is indicated, then the sys-
tem contains non-condensables. See S-114 Non-
Condensables.
S-114 NON-CONDENSABLES
Check for non-condensables.
1. Shut down the system and allow the pressures to equalize
for a minimum of 15 minutes.
2. Take a pressure reading.
3. Compare this pressure to the temperature of the coldest
coil since this is where most of the refrigerant will be. If the
pressure indicates a higher temperature than that of the
coil temperature, non-condensables are present.
To remove the non-condensables.
1. Remove the refrigerant charge.
2. Replace and/or install liquid line drier
3. Evacuate and recharge.
S-115 COMPRESSOR BURNOUT
When a compressor burns out, high temperature develops caus-
ing the refrigerant, oil and motor insulation to decompose form-
ing acids and sludge.
If a compressor is suspected of being burned-out, attach a
refrigerant hose to the liquid line dill valve and properly remove
and dispose of the refrigerant.
V
IOLATION OF EPA REGULATIONS MAY RESULT
IN FINES OR OTHER PENALITIES.
NOTICE
Now determine if a burn out has actually occurred. Confirm by
analyzing an oil sample using a Sporlan Acid Test Kit, AK-3 or
its equivalent.
Remove the compressor and obtain an oil sample from the
suction stub. If the oil is not acidic, either a burnout has not
occurred or the burnout is so mild that a complete clean-up is
not necessary.
If acid level is unacceptable, the system must be cleaned by
using the clean-up drier method.
CAUTION
DO NOT ALLOW THE SLUDGE OR OIL TO CONTACT
THE SKIN, SEVERE BURNS MAY RESULT.
NOTE: The Flushing Method using R-11 refrigerant is no longer
approved by Goodman
®
Manufacturing Company, L.P.
Suction Line Drier Clean-Up Method
The POE oils used with R410A refrigerant is an excellent sol-
vent. In the case of a burnout, the POE oils will remove any
burnout residue left in the system. If not captured by the refrig-
erant filter, they will collect in the compressor or other system