Vogt P18AL TUBE-ICE, Service Manual

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P18AL Service Manual
START-UP AND OPERATION
3/6/07
5-3
Charging From Cylinders (dedicated high side only). The machine may also be charged from
refrigerant cylinders. To charge from cylinders, the compressor will have to operate to transfer the
ammonia from the freezer to the receiver. Again, make sure all the necessary valves are opened for
operation and the compressor crankcase heater has been energized for a minimum of four (4) hours.
Follow these instructions with caution:
1.
Using a approved for ammonia charging hose, connect one end to the charging valve (30)
located on the freezer.
2. Lay a full cylinder of anhydrous ammonia horizontally with the cylinder valve outlet pointing up
to withdraw liquid and the bottom end raised about 2” higher than the top end.
3. Connect the other end of the charging hose to the cylinder valve. It is recommended that a gage
be attached to this line to indicate cylinder pressure.
4. Close the liquid line stop valve (24) or the receiver liquid feed valve.
5. Open charging valve (30) and carefully purge air from the charging hose.
6. Open the cylinder valve slowly, checking for leaks in the line and allow the suction pressure to
build up to approximately 40 psig and check again for leaks in the system.
7. Set the freeze timer (T2) to maximum setting. If the machine contains a pressure switch in place
of the freeze timer, disconnect and lock out the power, open the control panel door and
disconnect the freezer pressure switch, then turn the power back on.
8. Check compressor rotation by starting and stopping the compressor momentarily. Jog the
compressor by using the green “Start” push button (PB2) and the red “Stop” push button (PB1)
in sequence. Correct compressor rotation is indicated by an arrow on the outer rim of the oil
pump assembly (opposite the shaft end of the compressor).
9. Set the “Clean/Off/Ice” Switch (SS) to the “Ice” position allowing the circulating water pump to
circulate water through the freezer.
10. As the pressure continues to rise in the freezer, start the compressor and pump the ammonia into
the receiver. Make sure water is circulating through the condenser and freezer tubes.
11. The machine will make ice during the process and care should be taken not to freeze the ice
solid. If necessary harvest the ice and repeat the process.
If a refrigeration system is being charged from refrigerant cylinders, disconnect each cylinder when
empty or when the system is fully charged. A gage should be installed in the charging line to
indicate refrigerant cylinder pressure. The cylinder may be considered empty of liquid R-717
refrigerant when the gauge pressure is 25 pounds or less and there is no frost on the cylinder. Close
the refrigerant charging valve and cylinder valve before disconnecting the hose from the cylinder.
Loosen the union in the refrigerant charging line--carefully to avoid liquid ammonia release into the
atmosphere.
! CAUTION !
Immediately close system charging valve at commencement of defrost or
thawing cycle if refrigerant cylinder is connected. Never leave a refrigerant
cylinder connected to system except during charging operation. Failure
to observe either of these precautions can result in transferring
refrigerant from the system to the refrigerant cylinder, over-filling it,
and possibly causing the cylinder to rupture because of pressure
from expansion of the liquid refrigerant.
! CAUTION !