Compressor Burnout; Refrigerant Piping; Aluminum Indoor Coil Cleaning; Suction Line Drier Clean-Up Method - Daikin ComfortNet DX16TC Series Service Instructions Manual

SERVICING
S-115 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 re-
frigerant 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 the manufacturer.

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 com-
pressor and/or spread contaminants throughout the system,
damaging additional components.
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 neces-
sary to use new tubing and form as required.
NOTE: At least twelve (12) inches of the suction line imme-
diately 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 car-
bon 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 deter-
mined and corrected before the new compressor is started.
S-120 REFRIGERANT PIPING
The piping of a refrigeration system is very important in
relation to system capacity, proper oil return to compressor,
pumping rate of compressor and cooling performance of the
evaporator.
POE oils maintain a consistent viscosity over a large tempera-
ture range which aids in the oil return to the compressor; how-
ever, there will be some installations which require oil return
traps. These installations should be avoided whenever possi-
ble, as adding oil traps to the refrigerant lines also increases
the opportunity for debris and moisture to be introduced into
the system. Avoid long running traps in horizontal suction line.

ALUMINUM INDOOR COIL CLEANING

(Qualified Servicer Only)
This unit is equipped with an aluminum tube evaporator coil.
The safest way to clean the evaporator coil is to simply flush
the coil with water. This cleaning practice remains as the
recommended cleaning method for both copper tube and
aluminum tube residential cooling coils.
An alternate cleaning method is to use one of the products list-
ed in the technical publication TP-109 (shipped in the literature
bag with the unit) to clean the coils. The cleaners listed are the
only agents deemed safe and approved for use to clean round
tube aluminum coils. TP-109 is available on the web site in
Partner Link > Service Toolkit.
NOTE: Ensure coils are rinsed well after use of any chemical
cleaners.
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