Manitowoc Marine Q 1800 Service Manual

Also see for Marine Q 1000: Use and care manual Installation instructions Service technician's handbook

Contents

23Electrical SystemWater Level Control CircuitryWATER LEVEL PROBE LIGHT FREEZE CYCLE CIRCUITRYThe water level probe circuit can be monitored bywatching the water level light. The water levellight is on when water contacts the probe, and offwhen no water is in contact with the probe. Thewater level light functions any time power isapplied to the ice machine, regardless of toggleswitch position.Manitowoc’s electronic sensing circuit does notrely on float switches or timers to maintainconsistent water level control. During the freezecycle, the water inlet valve energizes (turns on)and de-energizes (turns off) in conjunction withthe water level probe located in the water trough.During the first 45 seconds of the Freeze Cycle:• The water inlet valve is on when there is nowater in contact with the water level probe.Freeze Cycle Water Level SettingDuring the freeze cycle, the water level probe isset to maintain the proper water level above thewater pump housing. The water level is notadjustable. If the water level is incorrect, checkthe water level probe for damage (probe bent,etc.). Repair or replace the probe as necessary.WATER INLET VALVE SAFETY SHUT-OFFIn the event of a water level probe failure, thisfeature limits the water inlet valve to a six-minuteon time. Regardless of the water level probe input,the control board automatically shuts off the waterinlet valve if it remains on for 6 continuousminutes. This is important to remember whenperforming diagnostic procedures on the waterlevel control circuitry.• The water inlet valve turns off after watercontacts the water level probe for 3 continuousseconds.• The water inlet valve will cycle on and off asmany times as needed to fill the water trough.After 45 seconds into the Freeze Cycle:The water inlet valve will cycle on, and then offone more time to refill the water trough. The waterinlet valve is now off for the duration of the freezesequence.HARVEST CYCLE CIRCUITRYThe water level probe does not control the waterinlet valve during the harvest cycle. During theharvest cycle water purge, the water inlet valveenergizes (turns on) and de-energizes (turns off)strictly by time. The harvest water purgeadjustment dial may be set at 15, 30 or 45 seconds.SV1616WATERPUMPWATER LEVELPROBEWATER LEVELABOVE HOUSINGWATER PUMPIMPELLER HOUSINGPUMPOUTLET110°CONTROL BOARDNOTE: The water purge must be at the factorysetting of 45 seconds for the water inlet valve toenergize during the last 15 seconds of the WaterPurge. If set at 15 or 30 seconds the water inletvalve will not energize during the harvest waterpurge.SV16171530 45HARVEST WATER PURGEADJUSTMENT