Carrier 69NT40-541-306, Операция и обслуживание

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T-354 7–16
3. Connect the suction connection of the gauge manifold to the compressor suction service valve port, and
immerse the common connection of the gauge manifold in an open container of refrigeration oil. Extreme
care must be taken to ensure the manifold common connection remains immersed in oil at all times. Other-
wise air and moisture will be drawn into the compressor. Crack the suction service valve and gauge valve to
vent a small amount of refrigerant through the common connection and the oil to purge the lines of air. Close
the gauge manifold valve.
4. With the unit running, frontseat the suction service valve and induce a vacuum in the compressor crank
case. SLOWLY crack the suction gauge manifold valve and oil will flow through the suction service valve
into the compressor. Add oil as necessary.
Adding Oil to Service Replacement Compressor
Service replacement compressors are shipped without oil. If oil is present in the crankcase, it must be tested to
ensure it is the correct oil and that the moisture level is acceptable.
When adding oil to a service replacement compressor add three liters (6.3 pints) using an oil pump at the oil fill
valve (see item 11,
Figure 7.6 ). This quantity is recommended to allow for return of any oil that may be in the refrig-
erant system. Install compressor and check oil level after it is placed in operation (refer to Section 7.8.6 ).
Removing Oil from the Compressor
1.If the oil level is above one-eighth sight glass, oil must be removed from the compressor.
2. Close (frontseat) suction service valve and pump unit down to 1.2 to 1.3kg/cm

(2 to 4psig). Frontseat dis-
charge service valve and remove remaining refrigerant.
3. Loosen the oil drain plug on the bottom plate of the compressor and drain the proper amount of oil from the
compressor to obtain the correct level. Backseat the suction and discharge service valves.
4. Repeat step a to ensure proper oil level.
7.9 HIGH PRESSURE SWITCH
7.9.1 Replacing High Pressure Switch
1. Turn unit start-stop switch OFF. Frontseat both suction and discharge service valves to isolate compressor.
Remove the refrigerant from the compressor.
2. Disconnect wiring from defective switch. The high pressure switch is located on the center head and is
removed by turning counterclockwise (see Figure 3.3 ).
3. Install a new high pressure switch after verifying switch settings (refer to Section 7.9.2 ).
4. Evacuate and dehydrate the compressor per Section 7.6 .
7.9.2 Checking High Pressure Switch
WARNING
!
Do not use a nitrogen cylinder without a pressure regulator. Do not use oxygen in or near a
refrigeration system as an explosion may occur.
NOTE
The high pressure switch is non-adjustable.
1. Remove switch as outlined in paragraph Section 7.9.1
2. Connect ohmmeter or continuity light across switch terminals. Ohm meter will indicate no resistance or con-
tinuity light will be illuminated if the switch closed after relieving compressor pressure.
3. Connect hose to a cylinder of dry nitrogen (see Figure 7.16 ).
4. Set nitrogen pressure regulator at 26.4kg/cm

(375psig) with bleed-off valve closed.
5. Close valve on cylinder and open bleed-off valve.