VOGT ICE TUBE-ICE P-24A, Service Manual

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P24A & P34A Service Manual
START-UP & OPERATION
12/10/12
5-4
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 !
Transferring refrigerant from a refrigeration system into a cylinder can be very dangerous
and is not recommended.
As the machine is being charged, continually observe the following operating characteristics:
a) Discharge pressure - 175 psi to 200 psi maximum
b) Compressor oil pressure - (Mycom) 18-27 psi above suction, (Vilter 35-50 psi above suction)
c) Liquid level in receiver - marked on gage glass guard
d) Compressor cooling water - 100
° F outlet temperature
e) Compressor oil level - approximately 1/2 glass
While charging the machine, the low pressure switch will stop operation at approximately 15 psi
suction pressure. The switch will automatically reset at 35 psi at which time you can restart the
machine. It is best to use warm water in the tank and open the tank drain valve somewhat to allow
cold water to exit and warm water to enter continually. The idea is to prevent ice from freezing in
the tubes as much as possible while charging. It may be necessary to initiate a short harvest cycle to
dispel any ice made. To initiate a harvest cycle, close the charging valve and push the manual
harvest push button (3PB) while the compressor is running. As soon as all the ice clears the cutter
area, turn the Hand/Auto switch to “Hand” and then back to “Auto”. This will stop the harvest and
start another freeze to continue the charging procedure. When the liquid level in the receiver is near
the pumpdown level and the freezer is down to 15 psi suction with little of no frost on the shell, you
can stop the charging procedure and disconnect the cylinder. Make sure the charging valve is closed
and the cylinder valve is closed before attempting to disconnect the cylinder. Loosen the union in the
charging line gradually to relieve the ammonia pressure slowly.
When charging is complete, stop the machine, disconnect and lock-out the power. Open the control
panel door and reconnect wire #24 to the freezer pressure switch. Open valves #29 and #58 in the
liquid line and you will hear liquid refrigerant flowing through to the liquid solenoid valve #20.
Turn main power disconnect to the on position and the machine is read for start-up and ice
production.