Vogt P-34AL-15, Service Manual

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P34AL-15 & P34ALOF-15 Service Manual
START-UP & OPERATION
9/22/05
5-7
Operating Tips.
•
Make sure the machine is left running in the “Auto” position. This will assure a complete
shutdown if a safety or overload is tripped.
•
To initiate a harvest cycle, simply push the Manual Harvest push button (3PB).
•
To interrupt the harvest cycle (harvest timer 2TR) and revert to a freeze cycle, turn the
Hand/Auto switch to “Hand” and back to “Auto”.
•
The circulating water overflow tubing will show that water is being slightly lifted up the tubing
near the end of the freezing cycle. If this action ceases and water begins overflowing from the
top water box, it is an indication that the tubes are freezing solid and the machine should begin a
harvest cycle. It is best not to freeze the ice solid with no hole.
•
To cease ice production manually, allow the machine to complete the harvest period and start the
freeze period. When the “liquid feed” light comes on at the beginning of the freeze period, push
the “Stop” button to cease ice production.
Thaw Gas Regulating and Suction Regulating Valve Adjustment. The following is the
procedure for regulating valve adjustment. On dedicated compressor systems the suction regulating
valve is not required. However the compressor must unload by 50% or greater during the harvest or
a hot gas bypass must be installed.
1. Install gauge and gauge valve in gauge port of regulator.
2. Turn high pressure stem (down stream pressure) on suction regulator into the milled flats, do
not turn milled flats into packing nut.
3. Start the machine and initiate a harvest.
4. Adjust the thaw gas regulator to build pressure to 60 - 65 psig. ( 1 turn is approximately 13
psig)
5. Adjust (downstream) high pressure stem on suction regulator to begin regulating at 59-64 psig.
(slightly below the thaw gas regulator)
6. After the machine has completed the harvest cycle and returned to the freeze cycle, adjust the
low pressure (upstream pressure) on the suction regulator to maintain the required freezer
pressure. For clear ice a minimum of 20 psig freezer pressure is required.
NOTE: In attached systems where suction pressure drops significantly during the harvest
period; a bypass must be used to equalize the system pressures gradually during pull-down.
Failure to equalize the pressure properly will result in carry-over of liquid refrigerant.