Vogt TUBE-ICE P-118F, Service Manual

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P118F Service Manual
SERVICE OPERATIONS
1/6/09
9-11
Pumpdown. The function of the pumpdown is to transfer all the liquid refrigerant from the freezer
(evaporator) into the receiver. Pump-down should only be performed when the freezer is clear of
ice. Its main purposes are:
1. To check the total refrigerant charge.
2. To perform service or repair work on the machine.
3. To winterize the machine.
4. To prepare the machine for disconnecting and moving.
5. Before cleaning
To perform a pumpdown, follow this procedure:
1. Push manual harvest button to clear the freezer of all ice and stop operation.
2. Close the liquid stop valve (58) at the receiver.
3. Open the water tank drain valve partially to allow a continuous flow of warm
make-up water into the water tank, and still maintain a good level in the tank.
An auxiliary supply of warm water (not to exceed 100
°
F) may be used if
available. Warmer water affords a more complete pumpdown.
4. Start the machine and allow it to operate and complete one harvest
5. During the thaw cycle, close the 1/4" valve (69) at the top of the freezer to
isolate the freezer pressure switch and prevent another thaw cycle.
6. Allow the machine to operate until the low pressure switch stops the machine
@ 20 PSIG. If a lower pressure is desired, it can be accomplished by jumping
the low pressure switch and starting and stopping the machine by the "Start"
and "Stop" push buttons. Continually observe the oil level to make sure the oil
is not carried from the compressor while operating at a low pressure.
7. Close the thawing gas stop valve (90), the receiver liquid return stop valve (91),
the compressor suction valve (34), the compressor discharge valve and the oil
return stop valve (70).
Removal Of Refrigerant From The Machine. To transfer the refrigerant charge from the machine
into a separate container, proceed as instructed above under “Pumpdown”. This will isolate most of
the refrigerant in the receiver and the recovery unit can be connected to the access port (44) of the
hand stop valve (58) at the bottom of the receiver. Open the valve access port by turning the valve
stem in (front seat) and operate the recovery unit until the system is considered empty.
! WARNING !
Approved recovery equipment, hoses, gages, and refrigerant containers must be
used to comply with all local and federal EPA regulations.
! WARNING !
! WARNING !
Follow these instructions carefully.
Severe personal injury can result from improper
discharge of refrigerant.
! WARNING !