Vogt P18AL TUBE-ICE, Service Manual

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P18AL Service Manual
SERVICE OPERATIONS
3/6/07
9-8
6. Close the compressor discharge stop valve and the oil return valve. Make sure the power is
disconnected and locked-out.
7. Drain the compressor oil, remove the compressor side cover and clean the inside of all oil and
foreign matter, and reinstall the side cover.
8. Connect a vacuum pump, or pumps to the freezer and compressor, and evacuate them to 2000
microns or below while maintaining 60°F (10°c) or higher room temperature. A 5 CFM or
larger vacuum pump is best.
9. During evacuation, add new oil to the compressor. Also purge the receiver for non-
condensables.
10. After evacuation, break the vacuum by manually opening the liquid line solenoid valve and
gradually opening the liquid line stop valve (24) or at the receiver, letting liquid ammonia enter
the freezer and raise the pressure.
11. When the freezer (suction) pressure is up to at least 60 PSI, manually close the liquid line
solenoid valve and restore power to the machine.
12. Open the compressor discharge valve, oil return valve, and all other valves that should be opened
for normal operation.
13. When the receiver liquid level is near its normal operating level or the pressures are near equal
and the compressor crankcase has warmed, the compressor can be started and ice production
resumed.
14. After several cycles, check the system for symptoms of excessive water, and if necessary, repeat
the pumpdown and evacuation procedure.
Note: whenever excessive water is present in the system, the source should be identified and
corrections made prior to further operation.