Friedrich H)A09K25 Manual De Usuario

22

Remove the leads from the compressor terminals and set the 
ohmmeter on the lowest scale (R x 1).

Touch the leads of the ohmmeter from terminals common to 
start ("C" to "S"). Next, touch the leads of the ohmmeter from 
terminals common to run ("C" to "R").

Add values "C" to "S" and "C" to "R" together and check resis-
tance from start to run terminals ("S" to "R"). Resistance "S" 
to "R" should equal the total of "C" to "S" and "C" to "R."

In a single phase PSC compressor motor, the highest value 
will be from the start to the run connections (“S” to "R"). The 
next highest resistance is from the start to the common con-
nections ("S" to "C"). The lowest resistance is from the run to 
common. ("C" to "R") Before replacing a compressor, check 
to be sure it is defective.

Check the complete electrical system to the compressor and 
compressor internal electrical system, check to be certain that 
compressor is not out on internal overload.

Complete evaluation of the system must be made whenever 
you suspect the compressor is defective.  If the compressor 
has been operating for sometime, a careful examination must 
be made to determine why the compressor failed.

Many compressor failures are caused by the following condi-
tions.

1. Improper 

air 

fl ow over the evaporator.

2.  Overcharged refrigerant system causing liquid to be re-

turned to the compressor.

3.  Restricted refrigerant system.

4.  Lack of lubrication.

5.  Liquid refrigerant returning to compressor causing oil to 

be washed out of bearings.

6.  Noncondensables such as air and moisture in the system. 

Moisture is extremely de structive to a refrigerant system.

1.  Be certain to perform all necessary electrical and refrigera-

tion tests to be sure the compressor is actually defective 
before replacing .

2.  Recover all refrigerant from the system though the process 

tubes.  PROPER HANDLING OF RECOVERED RE-
FRIGERANT ACCORDING TO EPA REGULATIONS IS 
REQUIRED.  Do not use gauge manifold for this purpose 
if there has been a burnout.  You will contaminate your 
manifold and hoses. Use a Schrader valve adapter and 
copper tubing for burnout failures.

3.  After all refrigerant has been recovered, disconnect suction 

and discharge lines from the compressor and remove com-
pressor.  Be certain to have both suction and discharge 
process tubes open to atmosphere.

4. 

Carefully pour a small amount of oil from the suction stub 
of the defective compressor into a clean container.

5. 

Using an acid test kit (one shot or conven tional kit), test 
the oil for acid content according to the instructions with 
the kit.

6. 

If any evidence of a burnout is found, no matter how 
slight, the system will need to be cleaned up following 
proper procedures.

7. 

Install the replacement compressor.

8. 

Pressurize with a combination of R-22 and nitrogen and 
leak test all connections with an electronic or Halide 
leak detector. Recover refrigerant and repair any leaks 
found.

9. 

Evacuate the system with a good vacuum pump capable 
of a fi nal vacuum of 300 microns or less. The system 
should be evacuated through both liquid line and suction 
line gauge ports. While the unit is being evacuated, seal 
all openings on the defective compressor. Compressor 
manufacturers will void warranties on units received not 
properly sealed. Do not distort the manufacturers tube 
connections.

10.  Recharge the system with the correct amount of refriger-

ant. The proper refrigerant charge will be found on the unit 
rating plate. The use of an accurate measuring device, 
such as a charging cylinder, electronic scales or similar 
device is necessary.