Manitowoc S Installation, Use & Care Manual

Also see for S model: Use and care manual Installation, use & care manual Service manual Installation, use & care manual Installation, use & care manual

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Manitowoc S Installation, Use & Care Manual Manual pdf 38 page image

Ice Machine Operation Section 33-2 Part Number 000000966 03/09Sequence Of OperationNOTE: The toggle switch must be in the ice position andthe water curtain/ice dampers must be in place on theevaporator before the ice machine will start.INITIAL START-UP OR START-UP AFTERAUTOMATIC SHUT-OFF1. Water PurgeBefore the refrigerant compressor starts, the water pumpand water dump solenoid energize to purge the icemachine of old water. This feature ensures that the icemaking cycle starts with fresh water.Single evaporator models energize the harvest valve(s)and air compressor (when used) at the end of the waterpurge and they remain energized during refrigerationstartup.2. Refrigeration System Start-UpThe compressor, condenser fan motor and water fillvalve energize and 5 seconds later the harvest valve(s)and air compressor(s) de-energize.The fan motor is wired through a fan cycle pressurecontrol and will cycle on and off when the roomtemperatures is below 70 F (21 C) .FREEZE SEQUENCE3. PrechillThe compressor lowers the temperature of theevaporator(s) before the water pump is energized. Thewater fill valve will remain energized until water contactsthe water level probe.4. FreezeThe water pump(s) energizes and water flows over theevaporator. After water contacts the water level probethe water fill valve de-energizes. The water fill valve willcycle on and off one more time.The freeze cycle continues until the six minute freezelock expires and enough ice has formed to allow water tocontact the ice thickness probe. After approximately 10seconds of continual water contact, the harvestsequence is initiated.NOTE: Freeze lock is bypassed after moving the toggleswitch from OFF to ICE position for the first cycle only.HARVEST SEQUENCE5. Water PurgeThe air compressor (when used) and the harvestvalve(s) open at the beginning of the water purge todivert hot refrigerant gas into the evaporator.The water pump continues to run, and the water dumpvalve energizes to purge the water in the water trough.Single evaporator models energize the water fill valve forthe last 15 seconds of the water purge cycle.6. HarvestThe air compressor (when used) remains energized andthe harvest valve(s) remains open. The refrigerant gaswarms the evaporator causing the cubes to slide, as asheet, off the evaporator and into the storage bin.Single evaporator models - The sliding sheet of cubesopens the water curtain and bin switch.The momentary opening and re-closing of the bin switchterminates the harvest sequence and return to thefreeze sequence (Step 3 - 4.)Multiple evaporator models - The sliding sheet ofcubes opens the ice damper and bin switch. Themomentary opening and re-closing of the bin switch de-energized the harvest valve for the evaporator. When allof the bin switches have opened and closed the icemachine will terminate the harvest sequence and returnto the freeze sequence (Step 3 - 4.)AUTOMATIC SHUT-OFF7. Automatic Shut-OffWhen the storage bin is full at the end of a harvestsequence, the sheet of cubes fails to clear the watercurtain/ice damper and will hold it open. After the watercurtain/ice damper is held open for 30 seconds, the icemachine shuts off. The ice machine remains off for 3minutes before it can automatically restart.The ice machine remains off until enough ice has beenremoved from the storage bin to allow the ice to fall clearof the water curtain or all of the ice dampers. As thewater curtain/ice dampers swing back to the closedposition, the bin switch re-closes and the ice machinerestarts (steps 1 - 2), provided the 3 minute delay periodis complete.