Follett MCC400A/W - Manual (Page 19)

19
Service
Icemaker Operation
Follett’s icemaker consists of four distinct functional systems:
• Refrigeration system
• Water system
• Harvesting system
• Electrical control system
These four systems work together to accomplish the production and harvesting of ice. A problem in any one
of these systems will result in improper operation of the entire ice production cycle. When troubleshooting the
icemaker, it is important to analyze the entire system operation to determine which system is not functioning
properly, then pinpoint the component within that system that is malfunctioning. Determine what corrective action
must be taken before making any adjustments or replacing any components.
The icemaking process
The Follett icemaker uses a stainless steel jacketed evaporator and operates on a continuous freezing cycle. Water is
supplied to the evaporator from the water reservoir where the water level is controlled by a float valve. This valve also
shuts off the water supply when the icemaker is not running.
water
inlet
auger
compression nozzle
ice transport tube
evaporator
port
Harvest system diagram When the icemaker is running, a
layer of ice forms on the interior
surface of the evaporator. This ice
is continuously removed by a slowly
rotating (12 RPM) auger. The auger
carries the ice upward into the
cavity formed by the top bearing
housing and the compression
loop, where it is compressed to
remove excess water. When the
ice reaches the desired hardness
it rotates within the cavity and is
forced through a discharge port and
compression nozzle and into the
ice transport tube. The discharge
tube and compression nozzle
are slightly restricted to further
compress the ice and produce the
desired hardness. As the formation
of ice continues, ice in the transport
tube is pushed through the tube to
the storage compartment in the ice
dispenser or ice storage bin.
A solid state control board located
in the electrical box of the icemaker
controls the normal operation of the
icemaker and monitors gearmotor
torque. This control board will shut
down the icemaker should an
over-torque condition occur. It is
very important that you familiarize
yourself with the operational
sequences detailed in this manual
before attempting to service
the icemaker.