Vogt Tube-Ice HFO10, Руководство по обслуживанию

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9-8
Pumpdown
The pumpdown function transfers all the liquid refrigerant from the freezer (evaporator) into the receiver. This
function is only performed when the freezer is clear of ice and before or during the following operations:
•
Checking the total refrigerant charge
•
Performing service or repair work on the machine
•
Winterizing the machine
•
Preparing the machine for disconnecting and moving
•
Before cleaning
To perform a pumpdown, follow these steps:
1. Press Manual Harvest to clear the freezer of all ice and to stop operation.
2. Close the liquid stop valve (king valve) at the receiver.
3. Open the water tank drain valve partially to allow a continuous flow of warm makeup water into the
tank while still maintaining the appropriate water level. An auxiliary supply of warm water (not to
exceed 100°F [38°C]) may be used if available.
4. Start the machine and allow it to operate for one harvest.
5. During the harvest cycle, remove the Thaw timer to prevent another thaw cycle.
6. Allow the machine to operate until the low-pressure relay on the Vogt 450 stops the machine at 5 psig
(0.3 bar). Set the correct pressure.
7. Close the thawing gas stop valve, the receiver liquid return stop valve, the compressor suction valve, and
the compressor discharge valve.
Removing Refrigerant
To transfer the refrigerant charge from the machine into a separate cylinder or tank, proceed as instructed
above under
Pumpdown . This will isolate most of the refrigerant in the receiver, and the refrigerant recovery
unit can be connected to the 1/2-in. (DN 15) receiver drain valve connected to the tee below the receiver. The
access port of the liquid stop valve (king valve) is at the bottom of the receiver. Open the valve by turning the
valve stem out, and operate the refrigerant recovery unit until the system is considered empty.
Figure 34: Receiver Drain Valve
Receiver Drain Valve
King Valve