Electronic Ice Maker

  • View
    219

  • Download
    0

Embed Size (px)

Text of Electronic Ice Maker

  • 8/6/2019 Electronic Ice Maker

    1/12

    Electronic Icemaker

    GE Consumer Home Services Training

    TECHNICAL SERVICE GUIDE

    Pub # 31-9063 8/00

  • 8/6/2019 Electronic Ice Maker

    2/12

    CAUTION

    To avoid personal injury, disconnect power before servicing thisproduct. If electrical power is required for diagnosis or testpurposes, disconnect the power immediately after performing thenecessary checks.

    !IMPORTANT SAFETY NOTICE

    The information in this service guide is intended for use byindividuals possessing adequate backgrounds of electrical,electronic and mechanical experience. Any attempt to repair amajor appliance may result in personal injury and propertydamage. The manufacturer or seller cannot be responsible for theinterpretation of this information, nor can it assume any liability inconnection with its use.

    RECONNECT ALL GROUNDING DEVICES

    If grounding wires, screws, straps, clips, nuts, or washers usedto complete a path to ground are removed for service, they mustbe returned to their original position and properly fastened.

    GE Consumer Home Services TrainingTechnician Service Guide

    Copyright 2000

    All rights reserved. This service guide may not be reproduced in whole or in part

    in any form without written permission from the General Electric Company.

  • 8/6/2019 Electronic Ice Maker

    3/121

    POWER LED

    MAGNET 1MAGNET 2

    The control board contains two sensors(Hall effect sensors), that are similar to anelectronic reed switch. The sensors areactivated by magnets and are used to assistin controlling icemaker operation. One

    magnet, attached to the end of the ejectorarm, allows the control board to use magneticsensing to determine if the motor has reachedthe home position. The second magnet,located on the ice sensing arm (feeler arm),lets the control know whether the arm hasreached a fully extended position.

    The on-off rocker switch allows the

    icemaker to be turned off. When the switchis set to on, a green LED on the right side ofthe cover will light to show power is on. TheLED is also used to indicate certain icemakerfault conditions, such as an open or shortedthermistor, or a harvest cycle longer than 30minutes. When a fault occurs, the LED willblink 1/2 second on, 1/2 second off indefinitelyuntil the icemaker is turned off.

    Electronic Icemaker

    Beginning in the Spring 2001, a newlydesigned icemaker will be introduced inseveral refrigerators. This service guide willhelp you become familiar with the icemakerand its operation.

    The icemaker contains several new andinnovative features. It has an electroniccontrol board, an on-off switch, a seven icecube mold, a lever style feeler arm and athermistor to monitor temperature.

    To access thecontrol board andother componentswithin the icemaker,lift and remove theplastic plug at the topof the cover. Removethe Phillips screwholding the cover inplace.

    The control board is held in place by threePhillips screws. All wiring is connected to theboard by plug-on terminals.

  • 8/6/2019 Electronic Ice Maker

    4/122

    FULLY EXTENDED

    FEELER ARM

    THERMISTOR

    SPRING

    PHILLIPS

    SCREW

    Freeze

    The Freeze cycle is the period wherethe icemaker is waiting for the cubes to freezesolid. This period of time is based on analgorithm programmed into the electroniccontrol. The control makes these calculations

    once per second and takes into account thethermistors current resistance value and therate of resistance change. As a result, freezetimes vary based on refrigerator control settingsand environmental conditions (door openings,room temperature, etc.) but averageapproximately 75 minutes for each drop of 7ice cubes.

    Harvest

    The Harvest cycle will begin when thefreeze algorithm has been satisfied and the armis in the out or fully extended position. If thearm is in the in position when harvest is tobegin, a delay of 3 minutes will be added oncethe arm moves to the extended position. This3 minute delay allows drawer type ice bucketsto be removed for up to 3 minutes withoutstarting a harvest. The 3 minute delay will beginagain if the arm goes back to the in positionanytime during the delay period. The arm isspring loaded and will go to the out positionunless it is being held in position by an obstaclesuch as an ice cube.

    At the start of the harvest cycle, the mold heaterwill be turned on. One second later, the motorwill start. The heater will remain on until themold temperature is above 35.6F (2C) and a

    The feeler arm moves horizontally. A fullice bucket will prevent the arm from moving outto the fully extended position, stopping the nextharvest cycle until ice cubes are removed andthe arm is able to swing out completely

    The thermistor is mounted in the mold body,directly behind the control housing. Thethermistor provides two functions: to measurethe ice temperature during freezing and forwater level detection during fill.

    The normal icemaker sequence is to fill themold with water, wait until the water is frozen,harvest the ice and then repeat the cycle. Toaccomplish this, three cycles are programmedin the electronic control: Freeze, Harvest andWater Fill. The control also contains a Power-On Diagnostic Test mode, a Harvest Fix mode,a Fault mode and a Service Diagnostic Testmode.

  • 8/6/2019 Electronic Ice Maker

    5/12

  • 8/6/2019 Electronic Ice Maker

    6/124

    3 TIMES WITHIN 15 SECONDS

    Thermistor Diagnostics

    During icemaker operation, the controlcontinuously monitors the thermistor resistancevalue. If the thermistor is open or shorted (toohigh or too low in resistance), the icemaker willenter the Fault Mode. When in the fault mode,

    the LED will flash at the rate of 1/2 second onand 1/2 second off.A temperature of -40F (-40C) will be

    considered too low and a temperature of 176F(80C) is too high for normal operation tocontinue. When out of range, a fault mode willbe entered, yet the thermistor will continue tobe tested. If the reading should later fall withinthe valid range, the fault mode will end and theicemaker will enter the freeze cycle. If the motoris not home, the control will restart the harvestcycle, followed by the freeze cycle, but bypassthe water fill.

    Service Diagnostics

    During the first 15 seconds that poweris first applied to the icemaker, the ServiceDiagnostic Test mode may be entered. Theservice mode is entered by pushing the feelerarm from the out position to the in positionand back again 3 times and only 3 timeswithin15 seconds.

    Note: If the icemaker has already started aharvest cycle and the arm is moving, it may beimpossible to properly move the arm and enterthe service mode without allowing it to resetand powering up again.

    The service diagnostic mode consistsof a harvest cycle followed by a water fill. Theharvest cycle is entered immediately, regardlessof icemaker temperature or arm position.

    the freeze cycle. If the temperature is still below39.2F (4C) after 15 seconds, the control willassume an insufficient amount of water enteredthe mold. It will then energize the water valveagain for 2.5 seconds, delay for 15 seconds andtest again. After the second fill, if the thermistoris still below 39.2F (4C), a third fill for 2.4seconds will occur. There is a maximum of threefills available, at which point the fill cycle willend and the icemaker will enter the freeze cycle.No diagnostic information will show if 3 fills wereinsufficient to fill the icemaker mold. The tablebelow shows the possible water fill times:

    First Fill 5.1 seconds

    Second Fill 2.5 seconds

    Third Fill 2.4 seconds

    The ability of the control to fill up to threetimes can compensate for low water pressurebeing supplied to the icemaker.

    Power On Diagnostics

    When the icemaker is first connectedto power and if thermistor temperature is 50F(10C) or higher, the control will perform aPower On test before entering the freeze cycle.

    The test consists of the following: Turn on the motor until it reaches home thenext time. Turn on the water valve for 1/2 second. Turn on the heater for 1/2 second. Verify that the feeler arm was in the in andthen in the out position. Verify that the motor was not in the homeposition and then in the home position. Verify that the motor does not remain on afterbeing turned off. Proceed to the freeze cycle.

    Note: The power on test will only add 1/2 secondof water, which will not overflow the mold witha normal fill, but may cause a small cube whenthe refrigerator is first started.If the temperature is below 50F (10C), thecontrol will power up normally. If in the homeposition, the control will enter the freeze cycle.If the motor is not home, the control will enterthe harvest cycle but bypass water fill to avoidoverfilling the mold.

  • 8/6/2019 Electronic Ice Maker

    7/125

    While in the harvest cycle in the service mode,the heater will remain on for a minimum of 20seconds. The water fill cycle will initiate thefirst fill (5.1 seconds) without waiting for the moldto prechill. Only one water fill occurs duringthe service mode, whether the thermistor hasreached 39.2F (4C) or not. The icemaker willexit the service diagnostic test on its own andenter the normal freeze cycle.

    NOTE: When replacing an icemaker, the PowerOn test will probably occur since the moldtemperature will be above 50F (10C). Whilein the power on test, the Service Diagnostic testcan be initiated and will override the power ontest mode.

    MOTOR ONFREEZE

    CYCLEPRECHILL

    CYCLEO

    N

    VAL

    VE

    MOTOR ON3 MINUTES

    Waituntil frozen

    (minimum 30 minutes)

    About10 MINS.Less than

    35.6F (2C)

    5.1secs.

    NORMAL OPERATION(EJECTOR STARTING AT HOME POSITION)

    HEATER ON

    (usually takes about 60 minutes)

    HEATER ONuntil35.6F (2C)(minimum 20 seconds)

  • 8/6/2019 Electronic Ice Maker

    8/126

    No

    Ice

    No

    LED

    LE

    D

    Flashing

    NoF

    ill

    NoH

    arves

    t

    Ba

    dSw

    itch

    Loose

    Lead

    Con

    tro

    lBoa

    rdFa

    ilure

    Therm

    istor

    Fa

    ilure

    Ejec

    tor

    Not

    Home

    Con

    tro

    lBoa

    rdFa

    ilure

    Ba

    dTherm

    istor

    Loose

    Lead

    Wa

    ter

    Valve

    Fa

    ilure

    Wa

    ter

    Supp

    lyShu

    tOff

    Buc

    ke

    tFull

    Fee

    ler

    Arm

    Stuc

    k

    Therm

    istor

    Fa

    ilure

    Magne

    tFailure

    StalledMotor

    Con

    tro

    lBoa

    rdFa

    ilure

    Magne

    tFa

    ilure

    Con

    tro

    lBoardF

    ailure

    StalledMo

    tor

    TCOFa

    ilure

    Hea

    ter

    Elemen

    t

    Fa

    ilure

    Open

    Circu

    it

    Groun

    d

    Wrong

    Connec

    tion

    Jammed

    Cu

    be

    Hea

    ter

    Failure

    Mo

    tor

    Failure

    Winding

    Fa

    ilure

    Loose

    Lea

    d

    Loose

    /Bro

    ken

    Gear

    Ben

    t/Bro

    ken

    Sha

    ft

    Therm

    istor

    Fa

    ilure

    Con

    tro

    lBoard

    Fa

    ilure

    Co

    ntro

    lBoard

    Fa

    ilure

    Improper

    Wa

    ter

    Va

    lve

    Connec

    tion

    Wa

    ter

    Va

    lve

    Fa

    ilure

    Th

    erm

    istor

    No

    tDe

    tec

    ting

    Fill

    Ha

    rves

    tToo

    Early

    Wa

    ter

    Overf

    low

    ICEMAKER

    TROUBLESHOOTING

    (dispenser

    /icema

    kerreverse

    d)

    (d

    ue

    toex

    treme

    lyco

    ldinletwa

    ter)

  • 8/6/2019 Electronic Ice Maker

    9/127

    MOTOR L1

    TCO VALVE N HEATER

    THERMISTOR

    TERMINALS

    ORANGE

    RED

    WHITE

    ORANGE

    BLACK

    BROWN

    MOV1

    C12

    C13

    C1

    C14

    LD1

    DB1

    U2

    U1

    X1

    BLACK

    BLACK

    115 VOLTS AC. 60HZ

    PCB ASSEMBLY THERMISTOR

    MOLD BODY

    ICEMAKER

    MOTOR

    HEATER

    T.C.O.

    RED

    BLACK

    ORANGE

    ORANGE

    WHITE

    POWER

    SWITCH

    GROUND

    LINE NEUTRAL

    WATER

    VALVE

    GREENWITHYELLOWS

    TRIPE

    WHITEB

    ROWN

    O

    RANGE

  • 8/6/2019 Electronic Ice Maker

    10/128

  • 8/6/2019 Electronic Ice Maker

    11/12

  • 8/6/2019 Electronic Ice Maker

    12/1210

    9. The ability of the control to fill up to 3 times can compensate for ___________?A. Multiple ejectionsB. Service diagnosticsC. Low water pressure

    D. Extremely cold freezer

    10. When the icemaker is first connected to power and if thermistor temperature is 50F orhigher, the control will perform a _________________ before entering the freeze cycle.A. Harvest fixB. Series of fluctuationsC. Power on testD. Fault test

    11. During icemaker operation, the control continuously monitors the thermistors __________?A. ResistanceB. TemperatureC. Mode

    D. Diagnostics

    12. If the thermistor is open or shorted, the icemaker will enter a ______________?A. Harvest modeB. Period of inactivityC. Fault modeD. Third water fill

    13. The diagnostic service mode is entered by pushing the feeler arm from the out position tothe in position and back _______ times during the first 15 seconds after applying power tothe unit.A. 2B. 3C. 4D. 5