Compressor Burnout; Suction Line Drier Clean-Up Method; Reversing Valve Replacement - Daikin M Series Service And Troubleshooting

SERVICING

Compressor Burnout

When a compressor burns out, high temperature develops
causing 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.
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.
Do not allow the sludge or oil to contact the skin. Severe
burns may result.
NOTICE
CAUTION
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 components.
Install a suction line filter drier. This drier should be
installed as close to the compressor suction fitting as
possible. The filter must be accessible and be rechecked
for a 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.

Reversing Valve Replacement

Remove the refrigerant charge from the system.
When brazing a reversing valve into the system, it is of
extreme importance that the temperature of the valve does
not exceed 250°F. at any time.
Wrap the reversing valve with a large rag saturated with
water. "Re-wet" the rag and thoroughly cool the valve after
each brazing operation of the four joints involved. The wet
rag around the reversing valve will eliminate conduction of
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