Ice-O-Matic UCG GOURMET Series Installation And Service Manual page 12

UCG GOURMET SERIES UNDERCOUNTER
On UCG105/135/165 air cooled versions the refrigerant head pressure is kept between two pre‐set
values (108,5 bar ‐ 140120 psig) with the unit a 21C (70F) ambient temperature. The declining of
the pressure is relied to the reduction of the evaporating pressure, caused by the progressive growth of
the ice thickness into the inverted cup molds and to the flow of air drown through the air cooled
condenser by the fan motor. The above values are in relation as well to the ambient temperature of the
ice maker site and they are subject to rise with the increase of this temperature.
On UCG45/65/85/105/135 water cooled versions the refrigerant head pressure ranges between 8.5 and
10 bars (120140 psig) being controlled by an automatic hi pressure control that energizes a water
solenoid valve located on the water line to the condenser, which rates the cooling water to the
condenser. On UCG165 water cooled versions the head pressure is constant at 9.5 bar (135 psig)
controlled by a water regulating valve.
At starting of freezing cycle the refrigerant suction or lo‐pressure lowers rapidly to 1.0 bar ‐ 14 psig then
it declines gradually ‐ in relation with the growing of the ice thickness ‐ to reach, at the end of the cycle,
approx. 00.1 bar ‐ 01.5 psig on the models UCG45/65/85 and 0.85 and 0.2 0.3 bar (34 psig) on
models UCG105/135/165 with the cubes fully formed in the cup molds. The total length of the freezing
cycle ranges from 23 to 25 minutes.
DEFROST OR HARVEST CYCLE
On UCG45/65/85105 the temperature of the evaporator thermostat, in contact with the evaporator
serpentine, drops to a pre‐set value it changes its electrical contacts energizing the herebelow shown
components. On U CG135/165 w hen t he t imer changes its electrical contacts energizing the same
components).
COMPRESSOR
WATER INLET SOLENOID
VALVE HOT GAS SOLENOID VALVE
The incoming water, passing through the water inlet valve and the flow control, runs over the
evaporator platen and then flows by gravity through the dribbler holes down into the sump/ reservoir.
The water filling the sump/reservoir forces part of the surplus water from the previous freezing cycle
to go out to the drain through the overflow pipe. This overflow limits the level of the sump water
which will be used to produce the next batch of ice cubes
Meanwhile the refrigerant, as hot gas discharged from the compressor, flows through the hot gas valve
directly into the evaporator serpentine by‐ passing the condenser.
The hot gas circulating into the serpentine of the evaporator warms up the copper molds causing the
harvest of the ice cubes. The ice cubes, released from the cups, drop by gravity onto a slanted cube
deflector, then through a curtained opening they fall into the storage bin.
pg. 12