Key Points - Imd / Wcc / Wcf Ice Makers; Superheat & Suction Temperature; Evaporator Squealing; Do Not Agitate - Cornelius IMD 600-90 Training Manual

KEY POINTS — IMD / WCC / WCF ICE MAKERS
S & S
UPERHEAT UCTION
Cornelius/Wilshire IMD/WCC/WCF ice makers run at only 4° F superheat. For this reason they are
equipped with non-adjustable expansion valves.
Suction temperature should be in the 5 to 8 degree below zero temperature range, regardless of refriger-
ant type.
E S
VAPORATOR QUEALING
Squealing noises coming from the evaporator always are accompanied by low production. These noises
are caused by a "rotational freeze". A rotational freeze is usually caused by mineral buildup on the evap-
orator wall. These deposits are not always visible, especially when the evaporator is wet. The production
of ice depends on the ice freezing to the wall of the evaporator and being shaved off by the auger.
The evaporator wall is belt sanded to create scratches from top to bottom. These scratches give the ice
something to hold onto, preventing it from rotating with the auger. If the grooves become filled with min-
eral deposits, the ice will not have any grip on the evaporator and begin to rotate, instead of being
shaved and pushed upward. The squealing noises are caused by the ice continuing to expand as it
rotates.
Ice sticking together in the bin is almost always the result of water chemistry. High concentrates of miner-
als in the water, chlorine, and salinity are usually found to be the cause. Filters that are specially
designed for ice makers usually contain chemicals called phosphates. These phosphates will prevent
minerals from freezing into the ice in cubers by keeping the particle in suspension and returning it to the
wastewater sump. In the WCC/WCF/IMD ice makers, there is no wastewater; therefore the chemical has
nowhere to go except into the ice bin with the ice. Once there, it behaves like salt, causing the ice to
breakdown and stick together. This can result in damaged agitator blades or a 200-LB block of ice may
be formed in a commercial bin. This effect is less pronounced in the WCF than it is in the WCC or IMD
models. There for phosphate feeders and scale inhibitors should not be used with WCC/WCF or
IMD ice makers.
D N A
O OT GITATE
Due to the slightly irregular shape of chunklet ice, it does not require timed agitation to remain loose. It is
an accepted practice to check with the manufacturer of a dispenser before using extruded ice. In some
cases, special agitator blades or bin liners may be required. Automatic agitation circuits must be turned
off or disabled on any dispenser serving extruded ice. If the agitation circuit is enabled it will cause the ice
to breakdown and not dispense properly. Eventually, the agitator blades may be damaged.
© 2003, IMI Cornelius Inc.
T
EMPERATURE
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Cornelius Ice Makers Training Manual
Publication Number: TP00967