Carrier 69NT40-541-001, Operation And Service

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T-316 7–6
7.6.3 Procedure - Complete System
a. Remove all refrigerant using a refrigerant recovery system.
b. The recommended method to evacuate and dehydrate the system is to connect three evacuation hoses
(see Section 7.5 ) to the vacuum pump and refrigeration unit. Be sure the service hoses are suited for evac-
uation purposes.
c. Test the evacuation setup for leaks by backseating the unit service valves and drawing a deep vacuum with
the vacuum pump and gauge valves open. Shut off the pump and check to see if the vacuum holds. Repair
leaks if necessary.
d. Midseat the refrigerant system service valves.
e. Open the vacuum pump and electronic vacuum gauge valves, if they are not already open. Start the vacuum
pump. Evacuate unit until the electronic vacuum gauge indicates 2000 microns. Close the electronic vac-
uum gauge and vacuum pump valves. Shut off the vacuum pump. Wait a few minutes to be sure the vac-
uum holds.
f. Break the vacuum with clean dry refrigerant 134a gas. Raise system pressure to approximately 0.2 kg/ cm²
(2 psig), monitoring it with the compound gauge.
g. Remove refrigerant using a refrigerant recovery system.
h. Repeat steps e.and f. one time.
Figure 7.5 Compressor Service Connections
1. Reclaimer
2. Discharge Service Valve
3. Compressor
4. Suction Service Valve
5. Receiver or Water Cooled Condenser 6. Liquid Service Valve
7. Vacuum Pump
8. Electronic Vacuum Gauge
9. Manifold Gauge Set
10. Refrigerant Cylinder
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