Ice-O-Matic ICE0250 Series Electrical System, Control Circuit, Selector Switch, Contactor

Disconnect power before servicing

ICE Series Electrical System

Control Circuit

All machines in this manual are electro-mechanical controlled; however the control circuitry on the single evaporator units differs from the dual evaporator units and is detailed below.

Selector Switch

The selector switch is used to put the machine into the ICE making or WASH cycle or to turn the machine OFF. The WASH position allows only the water pump to run and is used during the cleaning process to circulate cleaning solution throughout the water system. When the selector switch is turned to the ICE position, the machine begins the freeze cycle.

Contactor

When the selector switch is in the ICE position, the contactor coil is energized and pulls in the contactor contacts. This energizes the compressor start components, which starts the compressor.

Purge Switch

The purge switch is a momentary switch used to manually energize the purge valve. It is used during the cleaning process to flush the cleaning solution from the water trough. The purge valve will remain energized as long as the purge switch is depressed.

Note: Single Evaporator Units. The normally closed contacts of the purge switch also create a circuit to relay 1. These contacts should remain closed unless the switch is depressed. If the switch is defective and the normally closed contacts are open when the machine enters harvest, the machine will return to freeze when the timer initiate control opens.

Compressor and Start Components

The compressor should run during the entire cycle. If the machine is in the ICE position but the compressor is not running, check the compressor contactor to see if it is engaged. If the contactor is not engaged, the problem is not with the compressor or the compressor start components. If the contactor is engaged and there is correct voltage through the contactor, there could be a problem with one of the starting components or the compressor. It is recommended that the compressor starting components be replaced when replacing a compressor.

Compressor Check

If the compressor uses an internal overload, be

certain that the compressor has cooled and the overload has reset before diagnosing the compressor. If the compressor is cool and is still not running, check the compressor motor windings by first removing the wires at the compressor terminals. With an ohmmeter, check for continuity between all three terminals, if an open circuit exists between any of the terminals, the compressor may need to be replaced. Check for continuity from each terminal to the compressor body, if continuity is found from any terminal to the compressor body, the compressor windings are shorted to ground and the compressor will need to be replaced. If the compressor appears to be good at this point, it is advisable to use a compressor analyzer to isolate the compressor from the start components while checking for a locked rotor. If an analyzer is not available, the compressor starting components must be checked.

Page F1