Ice-O-Matic EMF Series Electrical System, Compressor Delay, Pump Down System Remote Only, Page G5

Flake Ice Machines Electrical System

Compressor Delay

When the machine starts, the compressor delay timer is energized. Once the timer counts out, the contactor is energized and the compressor starts.

The compressor delay timer will keep the compressor off for approximately 5 minutes when the machine restarts for any reason. This will reduce the load on the auger drive system. On remote units, the compressor delay timer energizes the liquid line solenoid.

Note: The compressor delay timer is only utilized on the EMF1106/5 and EMF2306/5 units.

Pump Down System (Remote Only)

If a remote machine is shut down by the selector switch or bin control, the liquid line solenoid valve is de-energized allowing the valve to close. This blocks the flow of refrigerant causing all the refrigerant to be pumped into the receiver and condenser. This is done to prevent liquid refrigerant from migrating into the compressor during the off cycle, which could damage the compressor on start-up. Also see Pump Down System in the Refrigeration Section on page F11. As the refrigerant is pumped into the receiver, the suction pressure begins to drop. Once the suction pressure reaches approximately 19 psi (1.7 bar) the pump down control contacts open, which will de-energize the compressor contactor.

Pump Down Control

The pump down control is a low pressure control that shuts the machine off when the suction pressure drops during the pump down phase. The control is factory set to open at 19 psi (1.7 bar) and close at 45 psi (3.1 bar). The pump down control does not normally need to be adjusted, however an adjustment may be made by turning the adjustment screw,

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