HEC-Series Service Manual
INITIAL START UP AND OPERATION
10/21/01
5-3
Refrigerant Charge.
Check the refrigerant level after the machine has operated for a few cycles. It
should be slightly above the operating level, as indicated on the receiver, a few minutes prior to start
of a thawing period. If this level is low at this time, sufficient refrigerant should be added to the
system to raise the level above this point. One inch (1”) is equivalent to 5 lbs. in the receiver. Add
only a small quantity (5 lbs. or less) at a time, and operate the machine several cycles to check the
level before adding additional refrigerant. Refrigerant may be added as a liquid through the charging
valve (28) only while the machine is operating. It is important that no air or other non-condensable
gases enter the system when charging refrigerant into the unit.
When adding refrigerant to the system, it may also be necessary to add lubricating oil. See
“Lubrication Compressor”, Section 7, “Maintenance”.
In order to check the total charge in the system, it is necessary to transfer all of the refrigerant to the
receiver. A total pumpdown procedure should be performed.
Total Pumpdown Mode.
The function of the total pumpdown mode is to transfer all the liquid
refrigerant from the freezer (evaporator) into the receiver. Total pumpdown is initiated as the first
phase of and prior to entering the clean mode. It should only be performed when the freezer is clear
of ice.
Its main purpose is to clear the freezer of liquid refrigerant and prevent possible refrigerant migration
to the compressor while running the clean cycle. It also can be used to check the units total
refrigerant charge.
Total pumpdown is initiated by setting the selector switch to the “Cyl” position, turn “Ice” switch to
the “Off” position (allow the machine to harvest if running in a freeze cycle), press the “Clean” button
to the “On” position. At this time the compressor and water pump will run, the “A” (liquid feed)
solenoid valve will close and the freezer will begin to pump down. As the suction pressure decreases,
the freezer pressure switch will initiate a harvest cycle to clear the partially formed ice cylinders from
the freezer. This harvest cycle will end after one minute and the total pumpdown will resume,
continuing until the compressor cycles off by the low pressure switch. At this time, only the water
pump will be running. The “Clean” push button must then be pushed to the “Off” position and the
machine will go to the standby mode.
To restart the machine after a total pumpdown:
1. Set the selector switch to the position desired (dual ice type machines only).
2. See that the “Clean” switch is in the “Off” position.
3. Push the “Ice” button to the “On” position.
4. Push the “Start” button.
At this time, the “A” (liquid feed) solenoid valve will open for 2 minutes and the machine will start in
a freeze cycle.
! CAUTION !
If the power has been turned off to the machine, make sure the compressor crankcase is warm
and there is no liquid refrigerant in with the oil before restarting the unit.
! CAUTION !
Summary of Contents for HEC-10
Page 1: ...HEC SERVICE MANUAL ...
Page 95: ...HEC Series Service Manual SERVICE OPERATIONS 10 21 01 9 13 FIGURE 9 9 Cutter Water Tank Parts ...
Page 96: ...HEC Series Service Manual SERVICE OPERATIONS 10 21 01 9 14 FIGURE 9 10 Cutter Drive Parts ...
Page 97: ...HEC Series Service Manual SERVICE OPERATIONS 10 21 01 9 15 FIGURE 9 11 Cutter Parts ...
Page 106: ...HEC Series Service Manual MODEL NUMBER STRUCTURE 10 21 01 10 1 10 Model Number Structure ...
