Friedrich SH15L30-B Benutzerhandbuch

7

 NOTE: This procedure can be sped up by the use of 

heat lamps, or by breaking the vacuum with refrigerant 
or dry nitrogen at 5,000 microns. Pressure system to 5 
PSIG and leave in the system a minimum of 10 minutes. 
Recover refrigerant, and proceed with evacuation to a 
pressure of 200 microns or a minimum of 10%.

11.  Break the vacuum by charging the system from the high 

side with the correct amount of refrigerant specifi ed. This 
will prevent boiling the oil out of the crankcase.

 

NOTE: If the entire charge will not enter the high side, 

allow the remainder to enter the low side in small 
increments while operating the unit.

The following procedure applies when replacing components 

in the sealed refrigeration circuit or repairing refrigerant leaks. 

(Compressor, condenser, evaporator, capillary tube, refrigerant 

leaks, etc.)

1.  Recover the refrigerant from the system at the process 

tube located on the high side of the system by installing 
a line tap on the process tube. Apply the gauge from the 
process tube to EPA approved gauges from the process 
tube to the EPA approved recovery system. Recover the 

CFC’s in the system to at least 5%.

2.  Cut the process tube below the pinch off in the suction side 

of the compressor.

3.  Connect the line from the nitrogen tank to the suction 

process tube.

4.  Drift dry nitrogen through the system and unsolder the 

more  distant  connection  first.  (Filter  drier,  high  side 
process tube, etc.)

5.  Replace the inoperative component, and always install a 

new fi lter drier. Drift dry nitrogen through the system when 
making these connections.

6.  Pressurize the system to 30 PSIG with proper refrigerant 

and boost the refrigerant pressure to 150 PSIG with dry 
nitrogen.

7.  Leak test the complete system with the electric halogen 

leak detector, correcting any leaks found.

8.  Reduce the system to zero gauge pressure.

9.  Connect the vacuum pump to the high side and low side 

of the system with deep vacuum hoses, or copper tubing. 

(Do not use regular hoses.)

10.  Evacuate the system to an absolute holding pressure of 

200 microns or less.

12.  Restart the unit several times after allowing pressures 

to stabilize. Pinch off the process tubes, cut and solder 
the ends. Remove the pinch off tool, and leak check the 
process tube ends.

1.  Recover all refrigerant and oil from the system.

2.  Remove the compressor, capillary tube and fi lter drier from 

the system.

3.  Flush the evaporator, condenser and all connecting tubing 

with dry nitrogen, or equivalent, to remove all contamination 
from the system. Inspect the suction and discharge lines 
for carbon deposits. Remove and clean if necessary.

4.  Reassemble the system, including a new drier-strainer and 

capillary tube.

5.  Proceed with processing as outlined under hermetic 

component replacement.

Basically, troubleshooting and servicing rotary compressors 
is the same as on the reciprocating compressor with only a 
few exceptions.

1.  Because of the spinning motion of the rotary, the mounts 

are critical. If vibration is present, check the mounts 
carefully.

2.  The electrical terminals on the rotary are in a different order 

than the reciprocating compressors. The terminal markings 
are on the cover gasket. Use your wiring diagram to insure 
the correct connections.

1.  The refrigerant charge is extremely critical. Measure the 

charge carefully and as exactly as possible to the nameplate 
charge.

2.  The correct method for charging the rotary is to introduce 

liquid refrigerant into the high side of the system with the 
unit off. Then start the compressor and enter the balance 
of the charge, gas only, into the low side.

 

The introduction of liquid into the low side, without the use of 

a capillary tube, will cause damage to the discharge valve 
of the rotary compressor.

NOTE: All inoperative compressors returned to Friedrich 
must have all lines properly plugged with the plugs from 
the replacement compressor.