Manitowoc Ice manual Harvest Sequence 5. Water Purge, Automatic SHUT-OFF 7. Automatic Shut-Off

Section 3 Ice Machine Operation

HARVEST SEQUENCE 5. Water Purge

The harvest valve(s) opens at the beginning of the water purge to divert hot refrigerant gas into the evaporator.

The water pump continues to run, and the water dump valve energizes for 45 seconds to purge the water in the sump trough. The water fill valve energizes (turns on) and de-energizes (turns off) strictly by time. The water fill valve energizes for the last 15 seconds of the 45-second water purge.

After the 45 second water purge, the water fill valve, water pump and dump valve de-energize. (Refer to “Water Purge Adjustment” for details.)

6. Harvest

The harvest valve(s) remains open and the refrigerant gas warms the evaporator causing the cubes to slide, as a sheet, off the evaporator and into the storage bin. The sliding sheet of cubes swings the water curtain out, opening the bin switch.

The momentary opening and re-closing of the bin switch terminates the harvest sequence and returns the ice machine to the freeze sequence (Step 3 - 4.)

When Used - The air compressor energizes after 35 seconds and remains energized throughout the entire harvest cycle. The air compressor will automatically energize for 60 seconds when the harvest cycle time exceeded 75 seconds in the previous cycle.

AUTOMATIC SHUT-OFF 7. Automatic Shut-Off

When the storage bin is full at the end of a harvest sequence, the sheet of cubes fails to clear the water curtain and will hold it open. After the water curtain is held open for 30 seconds, the ice machine shuts off. The ice machine remains off for 3 minutes before it can automatically restart.

The ice machine remains off until enough ice has been removed from the storage bin to allow the ice to fall clear of the water curtain. As the water curtain swings back to the operating position, the bin switch re-closes and the ice machine restarts (steps 1 - 2), provided the 3 minute delay period is complete.

SAFETY TIMERS

The control board has the following non-adjustable safety timers:

•The ice machine is locked into the freeze cycle for 6 minutes before a harvest cycle can be initiated. Freeze lock is bypassed after moving the toggle switch from OFF to ICE position for the first cycle only.

•The maximum freeze time is 60 minutes at which time the control board automatically initiates a harvest sequence (steps 5 & 6).

•The maximum harvest time is 3.5 minutes at which time the control board automatically initiates a freeze sequence (steps 3 & 4).

WARM WATER RINSE CYCLE

Closing the back of the evaporator allows ice to build up on the rear of the evaporator and the plastic evaporator frame parts. After 200 freeze/harvest cycles have been complete the control board will initiate a warm water rinse.

After the 200th harvest cycle ends:

•The Clean and Harvest LED’s energize to indicate the ice machine is in a warm water rinse.

•The compressor and harvest valve remain energized.

•The water pump energizes.

•The water inlet valve energizes until water contacts the water level probe.

•The compressor and harvest valve warm the water for 5 minutes, then de-energize.

•The water pump remains energized for an additional 5 minutes (10 minute total on time) then de- energizes.

NOTE: The warm water rinse cycle can be terminated by moving the toggle switch to the OFF position, then back to ICE.

Part Number 80-1620-3 3-3