Vogt P-24AL Service Manual Download

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P24AL & P34AL Service Manual

SERVICING OPERATIONS

12/2016

9-20

Close the compressor discharge stop valve and the oil return valve. Make sure the power is
disconnected and locked-out.

Drain the compressor oil, remove the compressor side cover and clean the inside of all oil and
foreign matter, and reinstall the side cover.

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.

10.

During evacuation, add new oil to the compressor. Also purge the receiver for non-
condensables.

11.

After evacuation, break the vacuum by manually opening the liquid line solenoid valve and
gradually opening the liquid line stop valve (29 or at the receiver), letting liquid ammonia enter
the freezer and raise the pressure.

12.

When the freezer (suction) pressure is up to at least 60 psig, manually close the liquid line
solenoid valve and restore power to the machine.

13.

Open the compressor discharge valve, oil return valve, and all other valves that should be opened
for normal operation.

14.

Turn the HAND/AUTO switch to HAND. 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.

15.

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.

Circulating Water Pump Motor

. The motor bearings are pre-lubricated and sealed. They require

no further lubrication. The pump should operate with the water level above the impeller housing.

The  pump  is  equipped  with  a  mechanical  seal  which  is  self-adjusting  and  requires  no  lubrication.
However,  the  pump  should  not  be  operated  unless  circulating  water.    The  pump  manufacturer
recommends  that  a  mechanical  seal  be  kept  as  a  spare.    When  ordering  a  seal,  specify  pump  size,
type, serial number, and manufacturer’s name as indicated on the nameplate.

Solenoid Valves

. The P24 and P34 are equipped with several solenoid valves to perform various

functions for proper operation and good ice production.

The Thaw Gas Solenoid Valve

(18)

, Figure 9-7, is opened during the thaw cycle to allow warm gas

to pass from the receiver to the freezer. Repair or replace as follows:

1.

With the receiver pressure higher than the freezer pressure, manually open the valve by turning
the manual stem out until you hear gas passing through the valve.

Close the two hand stop valves (90) tight on either side of solenoid valve when there is vapor
only in that part of the line.

Loosen the 1/4” tubing compression nut at the strainer slightly to purge that section of the thaw
gas line and continue to purge until all pressure is relieved.

Repair or replace the valve as needed making sure all connections are tight.