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sandcloth or sandpaper and wipe the area with clean, dry
cloths. Protect nearby parts from heat damage by wrapping
with water- soaked cloths.
For copper-to-copper (piping) repairs use a phosphorus
copper brazing alloy with 15% silver. General purpose silver
brazing alloy with 45% silver is to be used for copper-to-brass
or copper-to steel repairs.
When repairs are completed, remove all traces of flux and flush
the system. After any repair, pressurize the system to check for
leaks prior to recharging the system.
DX System
It may be necessary to perform repairs on the refrigeration
system. If field repairs are necessary, the following procedures
apply:
Leak Detection
Several methods can be used to detect a leak in the
refrigeration system. The most modern and easiest method is
to use an electronic leak detector. Follow the manufacturers
directions and any leak can be quickly located. A second
method is to use soap bubbles. Apply a solution of soapy water
with a brush or sponge to the joints and connections in the
refrigeration lines. A leak in the lines will cause bubbles to form.
Leak Repair
When a leak is located, properly reclaim the remaining
refrigerant charge before beginning repairs. Adjacent piping
must be thoroughly cleaned by removing all paint, dirt and oily
film. Use a wire brush, sandcloth or sandpaper and wipe the
area with clean, dry cloths. Protect nearby parts from heat
damage by wrapping with water-soaked cloths.
Refrigerant Piping
When replacing components within the cabinet of the unit, the
following consumable materials are recommended: When
brazing copper-to-copper connections (piping liquid line or
suction line), use a phosphorus copper brazing alloy with 15%
silver. General purpose silver brazing alloy with 45% silver is
to be used for copper-to-brass or copper-to steel. For liquid line
repairs at the drier, strainer, sight glass, or expansion valve,
use a 95% tin to 5% antimony solder with flux.
When component replacement is complete, remove all traces
of flux. After any repair, pressure check the system to ensure
there are no leaks prior to recharging the system.
Refrigeration System Repairs
Compressor Failure
The compressor is the most important component of the air
conditioner. Numerous safety devices are provided to protect
the compressor from failing.
If a compressor failure has occurred, determine whether it is an
electrical or a mechanical failure. An electrical failure will be
indicated by the distinct pungent odor once the system has
been opened. If a burnout has occurred, the oil will be black
and acidic. A mechanical failure will have no burned odor and
AH-SVX015A-EN
the motor will attempt to run, an abnormal or excessive noise
may be present.
An analysis of the oil is the only way to determine the proper
procedure for cleaning the refrigerant system. Acid test kits are
available from several manufacturers for measuring the acid
level in the oil. These are capable of making accurate acid
measurements, but if they are not available, a check of the oil
by sight and smell can give a quick indication if contamination
remains in the system.
CAUTION
Severe Burns!
Failure to follow instructions below could result in
severe burns.
Avoid touching or contacting the gas and oil with
exposed skin. Use long rubber gloves when handling
contaminated parts.
All electrical connections should be checked to ensure they are
tight and properly made. Check all circuit breakers, contactors
and wiring. The contactors should be examined and replaced
if contacts are worn or pitted.
If there is acid in the oil, there has been an electrical failure
which has caused the compressor motor to burn out. The acid
diffuses throughout the refrigeration system and must be
removed by using a burnout filter kit before a new compressor
is placed in service. Not only must the compressor be
replaced, but also the entire refrigeration circuit must be
cleaned of the harmful contaminants left by the burnout. See
"Standard Cleanout Procedure," p. 67
Cleanup) for the proper procedure.
If there is no acid in the oil, there has been a mechanical failure.
See
"Burn-Out/Acidic Cleanup Procedure," p. 68
Cleanout) for the proper cleaning procedure.
CAUTION
Damage to a replacement compressor caused by
improper system cleaning constitutes abuse under the
terms of the warranty. This will VOID THE
COMPRESSOR WARRANTY. Always consult the factory
prior to replacing the compressor.
Important:
PVE oil is used in systems with R410A
refrigerant. If a replacement compressor is
provided, ensure that it is filled with PVE oil
before installing.
Note: Cleaning operations must be performed by a
journeyman, refrigeration mechanic, or air conditioning
technician.
Standard Cleanout Procedure
1. Turn off power to unit at the main power disconnect switch.
2. Remove the old compressor and install the new
compressor.
Maintenance
(Burn-Out/Acidic
(Standard
67
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Troubleshooting
