Manitowoc Q130 Installation, Use & Care Manual

Also see for Q210 series: Replacement manual Installation, use & care manual Technician's handbook Installation and service manual Installation, use & care manual

Section 3 OperationPart Number 040002380 9/12 11Section 3OperationIce Making Sequence of OperationINITIAL START-UP OR START-UP AFTERAUTOMATIC SHUT-OFF1. Pressure EqualizationBefore the compressor starts the hot gas valve isenergized for 15 seconds to equalize pressures duringthe initial refrigeration system start-up.2. Refrigeration System Start-UpThe compressor starts after the 15-second pressureequalization, and remains on throughout the entireFreeze and Harvest Sequences. The hot gas valveremains on for 5 seconds during initial compressor start-up and then shuts off.At the same time the compressor starts, the condenserfan motor (air-cooled models) is supplied with powerthroughout the entire Freeze and Harvest Sequences.The fan motor is wired through a fan cycle pressurecontrol, therefore it may cycle on and off. (Thecompressor and condenser fan motor are wired throughthe relay. As a result, any time the relay coil is energized,the compressor and fan motor are supplied with power.)FREEZE SEQUENCE3. PrechillThe compressor energizes to prechill the evaporatorprior to water flow.4. FreezeThe water pump starts after the Prechill. An even flow ofwater is directed across the evaporator and into eachcube cell, where it freezes.When sufficient ice has formed, the water flow (not theice) contacts the ice thickness probe. Afterapproximately 7 seconds of continual water contact, theHarvest Sequence is initiated. The ice machine cannotinitiate a Harvest Sequence until a 6-minute freeze timehas been surpassed.HARVEST SEQUENCE5. HarvestThe water pump de-energizes stopping flow over theevaporator. The rising level of water in the sump troughdiverts water out of the overflow tube, purging excessminerals from the sump trough. The hot gas valve alsoopens to divert hot refrigerant gas into the evaporator.The refrigerant gas warms the evaporator causing thecubes to slide, as a sheet, off the evaporator and into thestorage bin. The sliding sheet of cubes contacts the icedamper, opening the bin switch.The momentary opening and re-closing of the bin switchterminates the Harvest Sequence and returns the icemachine to the Freeze Sequence (steps 3 - 4).AUTOMATIC SHUT-OFF6. Automatic Shut-OffWhen the storage bin is full at the end of a HarvestSequence, the sheet of cubes fails to clear the icedamper and will hold it down. After the ice damper isheld open for 7 seconds, the ice machine shuts off. Theice machine remains off for 3 minutes before it canautomatically restart.The ice machine remains off until enough ice has beenremoved from the storage bin to allow the ice to fall clearof the damper. As the ice damper swings back to theoperating position, the bin switch re-closes and the icemachine restarts (steps 1 - 2), provided the 3-minutedelay period is complete.