– 9 –
During the later stages of the freeze mode, an ice
slab forms on the evaporator freezing plate. This
ice slab causes some of the refrigerant passing
through the evaporator to not evaporate into a
gas, but remain a liquid. This liquid refrigerant
settles in the accumulator. The refrigerant vapor is
sucked off through the suction tube at the top of the
accumulator.
This accumulated liquid refrigerant will eventually
be directed to the evaporator to quickly warm the
evaporator plate during the harvest mode.
Caution:
It is very important that the accumulator
is not tilted out of a horizontal position. If moved, it
could cause compressor failure.
Water System:
The water recirculation pump
moves the water from the reservoir pan up to the
distributor. The water
fl
ows out over the evaporator
freezing plate. Water that does not freeze on the
evaporator plate runs off the front edge. It falls back
into the reservoir, where it is recirculated back to the
water distributor.
As the ice slab forms, the minerals in the water are
on the surface of the ice. The water
fl
owing over
the top of the ice slab washes these minerals back
into the water reservoir pan. The water continues to
recirculate until the water level in the reservoir drops
below a level determined by the water level sensor.
At this point, the control terminates the freeze mode
and initiates the harvest mode.
(Continued next page)
Operational Modes
There are 4 main operational modes for the
icemaker:
Ice-making cycle (Freeze Mode)
1.
Harvest
2.
Clean
3.
Service (Diagnostics)
4.
Ice-Making Cycle (Freeze Mode)
There are 3 possible “Off” cycles for the icemaker.
They occur when:
The bin is full of ice and the ON LED is
1.
illuminated (Idle Mode).
The OFF control pad has been held for 3 sec.
2.
(The ON LED will go out.)
The power is interrupted by over
fi
ll. (Model ZPK1
3.
only with internal drain pump.)
Electrical System:
Line voltage is supplied to
the electrical control switches and the primary
side of the step-down dual transformer. The dual
transformer reduces 120 VAC to 8.75 VAC for the
cutter grid and the bin light, and 12 VAC for the
drain and recirculating pumps.
The electronic control board directs 12 VAC to the
water recirculating and reservoir drain pumps, and
120 VAC to the hot gas solenoid, condenser fan
motor, and compressor.
The measured
fi
ll water inlet valve will always
have 120 VAC on the black and white wires and
14 VDC on the orange/white and black/red wires.
An evaporator thermistor supplies temperature
information to the electronic control to determine
when to terminate the harvest cycle. A water level
sensor initiates the next harvest.
Refrigeration System:
The hot gas refrigerant,
under high pressure, is forced through the
condenser, where it changes into a liquid and
fl
ows through the drier and capillary tube into the
evaporator. Under low pressure in the evaporator,
the liquid refrigerant absorbs heat from the
water
fl
owing over the evaporator and the liquid
refrigerant changes to gas. As a low-pressure gas,
the refrigerant
fl
ows back through the suction line of
the heat exchanger to the compressor.
During the freeze mode, some of the hot gas that is
in the condenser accumulating tube condenses to a
liquid and remains in the accumulating tube.
