Service; Important Preliminary Information; The Icemaking Process - Follett 12 Installation, Operation And Service Manual

Service

Important preliminary information

Follett's ice machine 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 system areas will result in improper operation of the entire ice production cycle. When troubleshooting the
ice machine, 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.
Note: When performing electrical service, always use a meter to determine whether or not components being
serviced are energized.

The icemaking process

The Follett ice machine 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 fl oat valve.
This valve also shuts off the water supply when the ice machine is not running.
When the ice machine 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 high quality. 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 ice machine controls the normal operation of
the ice machine and monitors gearmotor torque on an ongoing basis. This control board will shut down the
ice machine 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 ice machine.
Access to electrical box and control board
The 12 series electrical box has been designed to slide out for easy access to the control board and more
convenient troubleshooting.
1. Remove top and front panels of dispenser (for panel removal instructions see page 31).
2. Remove electrical box cover.
3. Pull electrical box toward front of unit.
14
electrical box
electrical box
cover
12CI400A • 12HI400A