Ice-O-Matic Control System Diagnostics, High pressure cut out check, MFI Series, Page

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MFI Series

Control System Diagnostics

The Control System consists of: ●Control Board

●Water Sensors

●Ice Sensors

●High Pressure Cut Out

●Low Pressure Cut Out

If the unit is OFF, check the control board:

1.Is the Power OK light on? If not check power to the unit. If it has power, and the Power OK light is not on, check the high pressure and low pressure cut outs. If they are both closed, replace the board. If the POWER OK light is ON, go to the next step.

2.Is the Water OK light on? If it is, go to the next step. If not, check the water level in the reservoir. If there is water in the reservoir, check that the water sensor is plugged in. To check the water sensor:

a.Unplug the water sensor.

b.Pull the water sensor from the reservoir.

c.Place one ohmmeter lead on the sensor’s plug and the other on the sensor’s tip. The meter should show nearly zero (0) resistance. If it reads infinite resistance, check the tip for corrosion. If it is clean and still reads open, replace the sensor.

OR, connect a copper wire to the wire where the water sensor plugs into and place the other end in the water. The WATER OK should go ON. If it does not, replace the board.

3.Ice sensor Check. Is the BIN FULL light OFF? If it is OFF and the SERVICE light is OFF and the unit is not running, replace the control board.

a.If it is OFF and the auger motor is running but the compressor is not, check the compressor contactor coil.

b.If it is ON, the ice sensors may be blocked. Remove them and check for mineral scale.

4.High pressure cut out check.

a. Disconnect electrical power.

b. Pull the wires off the high pressure cut out.

c. Use an ohmmeter to determine if the switch is OPEN. If it is, check the discharge pressure. If the discharge pressure is less than 300 PSIG, replace the high pressure cut out.

d. If the high pressure cut out is open and the system has high discharge pressure, check for the cause.

5.Low pressure cut out check.

a.Disconnect electrical power.

b.Pull the wires off the low pressure cut out.

c.Use an ohmmeter to determine if the switch is OPEN. If it is, check the suction pressure. If the suction pressure is greater than 20 PSIG, replace the low pressure cut out.

d.If the low pressure cut out is open and the system has low suction pressure, check for the cause.

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Contents Ice-O-Matic SERVICE AND INSTALLATION MANUAL MFI Series11100 East 45th Ave Denver, ColoradoPage Introduction MFI SeriesKeep this manual for future reference PageTable of Contents Table Of ContentsMFI Series PageInspect Promptly Freight Claim ProcedureVisible Loss or Damage Concealed Loss or DamagePage WarrantyMFI Series Installation Guidelines For the InstallerElectrical Specifications AdjustmentsPage For The InstallerMFI Series Bin Application Ice Machine SpecificationsFor the Installer MFI SeriesStorage Bin LocationIce machine Water LimitationsMFI Series For the InstallerAllow 6 “Clearance for Air Circulation PageWater Inlet For the PlumberWATER COOLED MODELS AIR COOLED MODELSElectrical Connections For the ElectricianWater Cooled Models Air Cooled ModelsFor the Installer Final Check ListMFI Series PagePre-StartInspection Start UpStart Up MFI SeriesAir Cooled Model Shown Component DescriptionMFI Series PageComponent Description MFI SeriesPotential Relay The compressor start relay PageComponent Description MFI SeriesPage Ice Sweep Bearing Breaker/Divider AugerElectrical Sequence To ResetElectrical Sequence Shut DownWater System Operation WaterMFI Series PageLow Pressure Cut Out- Automatic Reset High Pressure Cut Out- Automatic ResetOperation Performance Typical Low Side PressureICE MAKING SYSTEM In place cleaning Sanitizing and Cleaningscheduled at a minimum of twice a year KEEP OUT OF THE REACH OF CHILDRENBearing Maintenance Bearing MaintenanceNote Left Hand Threads MFI SeriesBin Control Sensor Sensor MaintenanceWater Sensor MFI SeriesClean the air cooled condenser Maintenance Air CooledMFI Series Page1. Disconnect electrical power to the ice machine Auger MaintenanceAuger 2. Turn off the water supply to the ice machineSymptom Service DiagnosisPossible Cause Probable CorrectionSymptom Service DiagnosisMFI Series Possible Cause4.High pressure cut out check Control System DiagnosticsMFI Series PageWater Reservoir R&R- Water Reservoir, Bin ControlBin Controls Ice Level Sensors MFI SeriesR&R-Bearingand Breaker To Remove the Breaker Bearing AssemblyMFI Series PageTo Remove the Auger R&R-AugerMFI Series PageTo Remove the Water Seal R&R-WaterSealRemoval of the Water Seal To Replace the Water SealTo Replace the Evaporator R&R-EvaporatorTo Reassemble the Evaporator and Auger MFI SeriesR&R-GearMotor To Remove and Repair the Gear Motor AssemblyTo Check the Gear Motor To Inspect the Gear MotorR&R-FanBlade and Motor To Remove the Condenser Fan Motor AssemblyMFI Series PageService Refrigeration System ServiceRefrigeration Instructions for Liquid Charging R404AWiring Diagram MFI0500 Air, MFI0500 Water MFI0500 Wiring DiagramMFI Series PagePage MFI0800 Wiring DiagramMFI Series Wiring Diagram MFI0805, MFI1255 Air MFI0805/1255 Wiring DiagramMFI Series PageWiring Diagram MFI1256 Air MFI1256 Wiring DiagramMFI Series PageWhat to Do Before Calling for Service Service HistoryMFI Series Page