Carrier Transicold 69NT40-561-001 Operation And Service Manual page 119

7.7.2 Adding Refrigerant to System (Full Charge)
1. Evacuate unit and leave in deep vacuum (see
2. Place cylinder of R-134a on scale and connect charging line from cylinder to liquid line valve. Purge
charging line at liquid line valve and then note weight of cylinder and refrigerant.
3. Open liquid valve on cylinder. Open liquid line valve half-way and allow liquid refrigerant to flow into the unit
until the correct weight of refrigerant (see
It may be necessary to finish charging unit through suction service valve in gas form, due to pressure rise in
high side of the system.
4. Backseat manual liquid line valve (to close off gauge port). Close liquid valve on cylinder.
5. Start unit in cooling mode. Run for approximately 10 minutes and check the refrigerant charge.
7.7.3 Adding Refrigerant to System (Partial Charge)
1. Examine refrigerant system for any evidence of leaks, repair as necessary (see
2. Maintain the conditions outlined in
3. Fully backseat the suction service valve and remove the service port cap.
4. Connect charging line between suction service valve port and cylinder of refrigerant R-134a. Open VAPOR
valve.
5. Partially frontseat (turn clockwise) the suction service valve and slowly add charge until the refrigerant
appears at the proper level. Be careful not to frontseat the suction valve fully, if the compressor is operated
in a vacuum, internal damage may result.
7.8 Compressor
Make sure power to the unit is OFF and power plug disconnected before replacing the compressor.
Before disassembly of the compressor, be sure to relieve the internal pressure very carefully
by slightly loosening the couplings to break the seal.
The scroll compressor achieves low suction pressure very quickly. Do not use the compressor
to evacuate the system below 0 psig. Never operate the compressor with the suction or dis-
charge service valves closed (frontseated). Internal damage will result from operating the com-
pressor in a deep vacuum.
7.8.1 Removal and Replacement of Compressor
1. Turn the unit ON and run it in full cool mode for 10 minutes.
If the compressor is not operational, front-seat the suction and discharge service valves and go to step e.
below.
Section
Section
NOTE
Section 7.7.1.
WARNING
!
WARNING
!
CAUTION
!
Replacement compressors are supplied without oil.
NOTE
7.6.1).
3.2) has been added as indicated by scales.
7–7
Section 7.5).
T-340