Manitowoc NEO UD0140A Installation, Operation And Maintenance Manual

Also see for NEO UD0140A: Technician's handbook Installation, operation and maintanance manual Technician's handbook Technician's handbook

Contents

14 Part Number: 04002909 Rev02 4/16Operation Section 3Ice Making Sequence of OperationNOTE: The On/Off button must be depressed and the icedamper must be closed before the ice machine will start.Water Purge CycleThe ice machine purges any remaining water from thewater trough down the drain.Freeze CyclePrechill - The refrigeration system chills the evaporatorbefore water flow over the evaporator starts. The water inletvalve energizes during the pre-chill and remains on untilthe ice thickness float switch is satisfied.Freeze - Water flowing across the evaporator cools as thefreeze cycle progresses. When the water temperaturereaches setpoint, the water pump will de-energize for 25seconds, then restart. Water flowing across the evaporatorwill start to freeze and build ice on the evaporator. After asheet of ice has formed, the harvest float switch signals thecontrol board to start a harvest cycle.Harvest CycleAny remaining water is purged down the drain asrefrigerant gas warms the evaporator. When the evaporatorwarms, the sheet of cubes slides off the evaporator and intothe storage bin. If all cubes fall clear of the ice damper, theice machine starts another freeze cycle.Full Bin CycleIf the ice damper is held open by ice cubes, the ice machineshuts off. When the ice damper closes, the ice machinestarts a new cycle at the water purge.Control Board TimersThe control board has the following non-adjustable timers:• The ice machine is locked into the freeze cycle for 6minutes before a harvest cycle can be initiated.• The maximum freeze time is 45 minutes, at which timethe control board automatically initiates a harvestsequence.• The maximum harvest time is 7 minutes. When harvestis complete the control board automatically initiates afreeze sequence.• If the ice damper does not open and close withinthe 7 minute harvest cycle, the ice machine entersa water thaw cycle for 170 seconds. If the damperdoes not open and close within the 170 second thawcycle, a second thaw cycle starts. The control boardautomatically initiates a freeze sequence when the thawcycle(s) is complete.SAFETY LIMITSSafety limits are stored and indicated by the control board.The number of cycles required to stop the ice machinevaries for each safety limit.Safety limits can be reset by pressing the On/Off button andstarting a new ice making cycle.A safety limit is indicated by an energized Service Light onthe touch pad. Refer to Section 5 if you receive a safety limitindication.• Safety Limit 1 - If the freeze time reaches 45 minutes,the control board automatically initiates a harvest cycle.After 6 consecutive 45-minute freeze cycles occur, theice machine stops.• Safety Limit 2 - If the harvest time reaches 3.5 minutes,the control board automatically energizes the waterpump and extends the harvest cycle another 3.5minutes (7 minutes total). If the ice damper does notopen and close within the 7 minute harvest cycle, theice machine enters a water thaw cycle for 170 seconds.If the damper does not open and close within the170 second thaw cycle, a second thaw cycle starts. Thecontrol board automatically initiates a freeze sequencewhen the thaw cycle(s) is complete. If 3 consecutive7 minute harvest and thaw cycles occur, the ice machinestops.• Safety Limit 3 - If the freeze time reaches 4 minutesand water is not sensed, the ice machine stops andinitiates a 30 minute delay period. The ice machine willautomatically restart at the end of the 30 minute delayperiod. If 100 consecutive failures occur, the ice machinestops.