GSZ16 Service Manual
SERVICING
114
S-114 NON-CONDENSABLES
If non-condensables are suspected, shut down the system and
allow the pressures to equalize. Wait at least 15 minutes.
Compare the 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.
Non-condensables are removed from the system by first remov-
ing the refrigerant charge, replacing and/or installing liquid line
drier, evacuating and recharging.
CHECKING COMPRESSOR EFFICIENCY
The reason for compressor inefficiency is broken or damaged
scroll flanks on Scroll compressors, reducing the ability of the
compressor to pump refrigerant vapor. The condition of the
scroll flanks is checked in the following manner.
1. Attach gauges to the high and low side of the system.
2. Start the system and run a “Cooling Performance Test. If the
test shows:
a. Below normal high side pressure.
b. Above normal low side pressure.
c. Low temperature difference across coil.
d. Low amp draw at compressor.
And the charge is correct. The compressor is faulty –
replace the compressor.
S-115 COMPRESSOR BURNOUT
When a compressor burns out, high temperature develops caus-
ing the refrigerant, oil and motor insulation to decompose
forming 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.
NOTICE
Violation of EPA regulations may result in fines
or other penalties.
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 Amana
®
Brand Heating-Cooling.
Suction Line Drier Clean-Up Method
The POE oils used with R410A refrigerant is an excellent solvent.
In the case of a burnout, the POE oils will remove any burnout
residue left in the system. If not captured by the refrigerant filter,
they will collect in the compressor or other system components,
causing a failure of the replacement compressor and/or spread
contaminants throughout the system, damaging additional com-
ponents.
Install a field supplied suction line drier. This drier should be
installed as close to the compressor suction fitting as possible.
The filter must be accessible and be rechecked for pressure drop
after the system has operated for a time. It may be necessary to
use new tubing and form as required.
NOTE: At least twelve (12) inches of the suction line immediately
out of the compressor stub must be discarded due to burned
residue and contaminates.
1. Remove compressor discharge line strainer.
2. Remove the liquid line drier and expansion valve.
3 Purge all remaining components with dry nitrogen or carbon
dioxide until clean.
4. Install new components including liquid line drier.
5. Braze all joints, leak test, evacuate, and recharge system.
6. Start up the unit and record the pressure drop across the
drier.
7. Continue to run the system for a minimum of twelve (12) hours
and recheck the pressure drop across the drier. Pressure
drop should not exceed 6 PSIG.
8. Continue to run the system for several days, repeatedly
checking pressure drop across the suction line drier. If the
pressure drop never exceeds the 6 PSIG, the drier has trapped
the contaminants. Remove the suction line drier from the
system.
9. If the pressure drop becomes greater, then it must be replaced
and steps 5 through 9 repeated until it does not exceed 6 PSIG.
NOTICE: Regardless, the cause for burnout must be determined
and corrected before the new compressor is started.