Hoshizaki KM660MRJ, KM520MRJ, KM520MAJ, KM350MWJ User Manual

Service Manual

Modular Crescent Cuber

Models
KM-350MAJ, MWJ
KM-520MAJ, MWJ, MRJ
KM-660MAJ, MWJ, MRJ

hoshizakiamerica.com

Number: 73230
Issued: 8-3-2018

WARNING

Only qualied service technicians should install and service the appliance. To
obtain the name and phone number of your local Hoshizaki Certied Service
Representative, visit www.hoshizaki.com. No service should be undertaken until
the technician has thoroughly read this Service Manual. Failure to service and
maintain the appliance in accordance with this manual will adversely affect safety,
performance, component life, and warranty coverage. Proper installation is the
responsibility of the installer. Product failure or property damage due to improper
installation is not covered under warranty.

Hoshizaki provides this manual primarily to assist qualied service technicians in the
service of the appliance.

Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, send an e-mail message, or write to the Hoshizaki Technical
Support Department for assistance.

Phone: [phone]
Fax: [phone]

E-mail: [e-mail]

618 Highway 74 South
Peachtree City, GA 30269
Attn: Hoshizaki Technical Support Department

Web Site: www.hoshizaki.com

NOTE: To expedite assistance, all correspondence/communication MUST include the

following information:

• Model Number

• Serial Number

• Complete and detailed explanation of the problem.

2

IMPORTANT

This manual should be read carefully before the appliance is serviced. Read
the warnings and guidelines contained in this manual carefully as they provide
essential information for the continued safe use, service, and maintenance of the
appliance. Retain this manual for any further reference that may be necessary.

CONTENTS

Important Safety Information ................................................................................................. 5

I. Construction and Water/Refrigeration Circuit Diagram ....................................................... 7

A. Construction .................................................................................................................. 7

1. Air-Cooled Models (MAJ) ......................................................................................... 7

2. Water-Cooled Models (MWJ) ................................................................................... 8

3. Remote Models (MRJ) ............................................................................................. 9

B. Water/Refrigeration Circuit Diagram ............................................................................ 10

1. Air-Cooled Models (MAJ) ....................................................................................... 10

2. Water-Cooled Models (MWJ) ..................................................................................11

3. Remote Models (MRJ) ........................................................................................... 12

II. Sequence of Operation and Service Diagnosis ............................................................... 13

A. Sequence of Operation Flow Chart ............................................................................. 13

1. Operation Flow Chart ............................................................................................ 13

2. Shutdown Flow Chart ............................................................................................ 14

3. Freeze-Time Correction Chart ............................................................................... 15

B. Service Diagnosis ....................................................................................................... 16

C. Freeze-Time Correction Cycle (90 min.) ..................................................................... 22

D. Control Board Check ................................................................................................... 24

E. Bin Control Check and Adjustment .............................................................................. 25

F. Float Switch Check and Cleaning ................................................................................ 28

G. Thermistor Check ........................................................................................................ 30

H. Control Switch ............................................................................................................. 30

I. Mode Switch ................................................................................................................. 30

J. Diagnostic Tables ......................................................................................................... 31

K. Freeze-Up Check List .................................................................................................. 35

III. Controls and Adjustments ............................................................................................... 36

A. Control Board Layout .................................................................................................. 37

B. LED Lights and Audible Alarm Safeties ....................................................................... 38

C. Settings and Adjustments ............................................................................................ 39

1. Default Dip Switch Settings .................................................................................... 39

2. Harvest Time (S4 dip switch 1 & 2)........................................................................ 40

3. Pump-Out Time/Harvest Time During Pump-Out (S4 dip switch 3 & 4) ................. 40

4. Pump-Out Frequency Control (S4 dip switch 5) ..................................................... 41

5. Harvest Pump Time (Harvest Assist) (S4 dip switch 6) ......................................... 41

6. Harvest Pump Time (Harvest Assist)/Freeze-Time Correction (S4 dip switch 7) .. 42

7. Factory Use (S4 dip switch 8)................................................................................. 42

8. Freeze Timer (S4 dip switch 9 & 10) ...................................................................... 43

9. Pump-Out Pump Motor Direction (S5 dip switch 1) ............................................... 43

10. Rell Counter (S5 dip switch 2 and 3) .................................................................. 44

11. Minimum Harvest Time (S5 dip switch 4) ............................................................. 44

12. Anti-Slush (S5 dip switch 5) ................................................................................. 44

3

IV. Refrigeration Circuit and Component Service Information.............................................. 45

A. Refrigeration Circuit Service Information .................................................................... 45

B. Component Service Information .................................................................................. 48

C. Water Regulating Valve Adjustment (water-cooled model) .......................................... 49

V. Maintenance .................................................................................................................... 50

VI. Preparing the Appliance for Periods of Non-Use ............................................................ 51

VII. Disposal ......................................................................................................................... 53

VIII. Technical Information .................................................................................................... 54

A. Specication and Performance Data Sheets ............................................................... 54

1. KM-350MAJ ........................................................................................................... 54

2. KM-350MWJ .......................................................................................................... 55

3. KM-520MAJ ........................................................................................................... 56

4. KM-520MWJ .......................................................................................................... 57

5. KM-520MRJ with URC-5F ..................................................................................... 58

6. KM-660MAJ ........................................................................................................... 59

7. KM-660MWJ .......................................................................................................... 60

8. KM-660MRJ with URC-5F ..................................................................................... 61

B. Wiring Diagrams ......................................................................................................... 62

1. KM-350M_J, KM-520M_J, KM-660M_J ................................................................. 62

4

Important Safety Information

Throughout this manual, notices appear to bring your attention to situations which could
result in death, serious injury, damage to the appliance, or damage to property.

WARNING Indicates a hazardous situation which could result in death or

serious injury.

NOTICE Indicates a situation which could result in damage to the

appliance or property.

IMPORTANT Indicates important information about the use and care of the

appliance.

WARNING

The appliance should be destined only to the use for which it has been expressly
conceived. Any other use should be considered improper and therefore dangerous.
The manufacturer cannot be held responsible for injury or damage resulting from
improper, incorrect, and unreasonable use. Failure to service and maintain the
appliance in accordance with this manual will adversely affect safety, performance,
component life, and warranty coverage and may result in costly water damage.

To reduce the risk of death, electric shock, serious injury, or re, follow basic
precautions including the following:

• Only qualied service technicians should install and service this appliance.

• The appliance must be installed in accordance with applicable national, state, and
local codes and regulations.

• Electrical connection must be hard-wired and must meet national, state, and local
electrical code requirements. Failure to meet these code requirements could result
in death, electric shock, serious injury, re, or severe damage to equipment.

• The icemaker requires an independent power supply of proper capacity. See the
nameplate for electrical specications. Failure to use an independent power supply
of proper capacity can result in a tripped breaker, blown fuses, damage to existing
wiring, or component failure. This could lead to heat generation or re.

• THE ICEMAKER MUST BE GROUNDED. Failure to properly ground the icemaker
could result in death or serious injury.

• Move the control switch to the "OFF" position and turn off the power supply before
servicing. Lockout/Tagout to prevent the power supply from being turned back on
inadvertently.

• To reduce the risk of electric shock, do not touch the control switch with damp
hands.

• Do not make any alterations to the unit. Alterations could result in electric shock,
injury, re, or damage to the unit.

• The appliance is not intended for use by persons (including children) with reduced
physical, sensory, or mental capabilities, or lack of experience and knowledge,
unless they have been given supervision or instruction concerning use of the
appliance by a person responsible for their safety.

5

WARNING, continued

• Children should be properly supervised around this appliance.

• Do not climb, stand, or hang on the appliance or allow children or animals to do so.
Serious injury could occur or the appliance could be damaged.

• Do not use combustible spray or place volatile or ammable substances near the
appliance. They might catch re.

• Keep the area around the appliance clean. Dirt, dust, or insects in the appliance
could cause harm to individuals or damage to the appliance.

Additional Warning for Remote Models

• THE REMOTE CONDENSER UNIT MUST BE GROUNDED. The power supply and
ground connection to the remote condenser unit are supplied from the icemaker.
Failure to properly ground the remote condenser unit could result in death or
serious injury.

• Move the icemaker control switch to the "OFF" position and turn off the power
supply to the icemaker before servicing the remote condenser unit.
Lockout/Tagout to prevent the power supply from being turned back on
inadvertently.

NOTICE

• Follow the instructions in this manual carefully to reduce the risk of costly water
damage.

• In areas where water damage is a concern, install in a contained area with a oor
drain.

• Install the appliance in a location that stays above freezing. Normal operating
ambient temperature must be within 45°F to 100°F (7°C to 38°C).

• Do not leave the icemaker on during extended periods of non-use, extended
absences, or in sub-freezing temperatures. To properly prepare the icemaker for
these occasions, follow the instructions in "VI. Preparing the Appliance for Periods
of Non-Use."

• Do not place objects on top of the appliance.

• The dispenser unit/ice storage bin is for ice use only. Do not store anything else in
the dispenser unit/ice storage bin.

6

I. Construction and Water/Refrigeration Circuit Diagram

A. Construction

1. Air-Cooled Models (MAJ)

Drain Valve

Cleaning Valve

Water Supply Inlet

Spray Tubes

Evaporator

Inlet Water Valve

Thermostatic
Expansion Valve

Float Switch

Compressor

Water Pump

Control Switch

Stainer

Hot Gas Valve

Condenser

High-Pressure
Switch

Fan Motor

Liquid Line
Valve

Drier

Bin
Control

Control Box

Mode Switch

Model Shown: KM-350MAJ

7

2. Water-Cooled Models (MWJ)

Cleaning Valve

Spray Tubes

Inlet Water Valve

Drain Valve

Water Supply Inlet

Stainer

Evaporator

Thermostatic
Expansion
Valve

Float Switch

Water Pump

Compressor

Control Switch

Mode Switch

Hot Gas Valve

Water Regulating
Valve

High-Pressure Switch

Condenser

Drier

Liquid Line Valve

Bin Control

Control Box

Model Shown: KM-520MWJ

8

3. Remote Models (MRJ)

Inlet Water Valve

Evaporator

Float Switch

Drain Valve

Spray Tubes

Cleaning Valve

Thermostatic
Expansion Valve

Water Supply Inlet

Stainer

Hot Gas Valve

Receiver Tank

High-Pressure
Switch

Drier

Water Pump

Crankcase Heater

Compressor

Liquid Line Valve

Bin Control

Control Switch

Control Box

Mode Switch

Model Shown: KM-660MRJ

9

B. Water/Refrigeration Circuit Diagram

1. Air-Cooled Models (MAJ)

Hot Gas

Val ve

Condenser

High-Pressure

Switch

Drier

Fan

Liquid Line Valve

Heat

Exchanger

Thermistor

Water Supply

Strainer

Suction Line

Discharge Line

Compressor

Thermostatic Expansion Valve

Spray Tubes

Inlet Water Valve

Water Pump

Drain

Refrigeration Circuit

Water Circuit

Evaporator

Cleaning Valve

Drain Valve

Float Switch

Water Tank

10

2. Water-Cooled Models (MWJ)

High-Pressure

Switch

Strainer

Hot Gas

Val ve

Discharge Line

Water Regulating Valve

Condenser

Inlet Water Valve

Drier

Thermostatic Expansion Valve

Suction Line

Heat

Exchanger

Liquid Line Valve

Thermistor

Water Supply

Cleaning Valve

Drain Valve

Float Switch

Compressor

Water Pump

Refrigeration Circuit

Water Circuit

Spray Tubes

Water Tank

Evaporator

Drain

11

3. Remote Models (MRJ)

High-Pressure

Switch

Strainer

Hot Gas

Val ve

Headmaster

(C.P.R.)

Fan

Remote Condenser

Receiver

Drier

Suction Line

Liquid Line

Val ve

Heat

Exchanger

Water Supply

Cleaning Valve

Inlet Water Valve

Thermistor

Drain Valve

Float Switch

Discharge Line

Compressor

Thermostatic Expansion

Val ve

Water Pump

Spray Tubes

Evaporator

12

Water Tank

Drain

Refrigeration Circuit

Water Circuit

II. Sequence of Operation and Service Diagnosis

A. Sequence of Operation Flow Chart

1. Operation Flow Chart

cycle

(S4 dip switch 5)

2 sec., then reverses for

10/20 sec.

• Pump motor stops for

(S4 dip switch 3 & 4)

FS in control

Comp energized

DV energized

FMR energized

HGV energized

PM de-energizes for 2 sec.,

then energizes for 10/20 sec.

FM de-energized

LLV de-energized

FS opens or freeze

timer terminates

Anti-Slush

Thermistor temperature

reaches 36°F (2.2°C)

(5.8 kΩ).

PM de-energized for

10 sec.

Freeze Time Differential Exceeded.

• Factory set for every 10th

4. Pump-Out Cycle

Initiate Freeze-Time Correction Cycle.

See "II.A.3. Freeze-Time Correction Cycle.

• Min. freeze time: 5 min.

3. Freeze Cycle

switch 9 & 10)

Correction starts at 2nd freeze cycle.

• Max. freeze time: freeze timer setting (S4 dip

• Freeze-Time monitoring for Freeze-Time

5-min.

minimum

freeze timer in

Harvest Pump

control

Timer

FS closed

50 sec.

Comp energized

FM energized

FMR energized

PM energized

LLV energized

HGV de-energized

FS check

FS open

Operation Flow Chart

PM energized

WV de-energized

FS closed

Thermistor temperature reaches

Comp energized

FMR energized

48°F (9°C) (3.9 kΩ or less).

Harvest timer starts.

HGV energized

WV energized

Components Energized when the Control Switch is in the "PUMP" Position

When the control switch is in the "PUMP" position power is supplied to the pump motor. Water tank contents then ows over the outside of the

evaporator plate assembly. Note: Water tank contents does not ow inbetween the evaporator plates.

(S4 dip switch 7), whichever is shorter. Do not adjust S4

dip switch 7 out of the factory position.

• WV time: 6 min. or the length of harvest minus 50 sec.

2. Harvest Cycle

1 to 3-min. harvest timer in

control (S4 dip switch 1 & 2)

Thermistor

in control

• Max. harvest time: 20 min.

WV energized

FS open

If FS is open, Comp stops and cycle returns to

1-Min. ll.

then initiates a clean/sanitze program. See the maintenance label on the top cover or the instruction manual for details.

over outside of evaporator plate assembly as the control board power supply has been disconnected. The Clean/Sanitize program cannot initiate in this scenario.

• When the control switch is in the "ON" position and the mode switch is in the "CLEAN" position power is supplied to the control board K9 connector. The control board

Legend:

BC–bin control

Comp–compressor

DV–drain valve

FM–fan motor

FMR–fan motor-remote

FS–oat switch

HGV–hot gas valve

LLV –liquid line valve

Components Energized when the Control Switch is in the "ON" or "PUMP" position and the Mode Switch

PM–pump motor

WV–inlet water valve

• When the control switch is in the "PUMP" position and the mode switch is in the "CLEAN" position, only the pump motor energizes and circulates water tank contents

is in the "CLEAN" Position

Fill Cycle

FS check

1. 1-Minute

Cycle

Steps

Startup

13

2. Shutdown Flow Chart

3. Ice Level Lowered

2. Icemaker Off

Icemaker starts at

All components

"1. 1-Minute Fill Cycle."

de-energized.

To 1. 1-Minute Fill Cycle

BC closed

(BC sensor disengaged)

Green UBC LED on

Yellow "BC OPEN" LED off

Yellow "BC OPEN" LED continues. All

components de-energized.

Shutdown Flow Chart

Control board retains freeze-time correction count data

between bin control restarts.

to 15 sec. into the freeze cycle if

activated at the end of the harvest cycle.

15 sec. before the 5-min. short cycle

protection timer terminates.

Otherwise, at the end of the next harvest

cycle.

BC open (BC sensor engaged)

Green UBC LED off

Yellow "BC OPEN" LED on

BC Operation

Legend:

BC–bin control

1. Bin Full

Shutdown

Shutdown Delay:

and Restart

• Fill Cycle–15 sec. after activation.

• Harvest Cycle–At the end of the harvest cycle, or up

• Freeze Cycle– 15 sec. after activation if activated at least

14

3. Freeze-Time Correction Chart

Overow

2. 10-Minute Fill/

WV energized

Comp de-energized

FMR de-energized

HGV de-energized

PM de-energized

After 5th 10-Minute Harvest Pump Cycle with WV

Freeze-Time Correction Cycle Complete.

Go to Step "3. Freeze Cycle" in Operation Flow Chart.

step 1 for 5th and nal time.

• Do not adjust S4 dip switch 7 out of the factory position.

• After step 2 completes 4th sequence (80 min. completed), repeat

1. 10-Minute Harvest Cycle with WV

Comp energized

FMR energized

HGV energized

PM energized

2A8242-01 Freeze-Time Correction Flow Chart

Cycle Steps

Steps 1 and 2 repeat

4 times (total 80 min.),

then step 1 repeats for

a 5th time to complete

Freeze-Time Correction

Start

Cycle.

WV energized

Legend:

Comp–compressor

FM–fan motor

FMR–fan motor-remote

HGV–hot gas valve

PM–pump motor

WV–inlet water valve

Appliance Cycle Reset and Alarm Reset:

Cycle Reset: Power Supply or Control Switch Turned Off and On again:

Appliance turns off, then re-starts at 1.Fill Cycle.

Alarm Reset: CB "ALARM RESET" pressed during or after a freeze-time

correction cycle with power supply on:

Appliance continues cycle with no interruption or reset.

CB red "POWER OK" LED blinking:

CB red "POWER OK" LED resets to solid.

CB yellow "EXT HARVEST" LED blinking:

CB yellow "EXT HARVEST: LED turns off.

Freeze Time Differential Exceeded.

Minimum and Maximum Recorded Freeze

times have exceeded 600 sec. (10 min.)

Freeze-Time Correction function is enabled

when S4 Dip Switch 7 is in the "ON" position

and initiates when the difference between

the minimum and maximum recorded freeze

times is equal to or greater than 600 sec.

(10min.).

Freeze time is recorded and freeze cycles

are counted starting at the 2nd freeze cycle

after startup from a power off condition.

After 6recorded freeze cycles, CB starts

comparing the minimum and maximum

differential ofrecorded freeze cycle times.

Up to 10 freeze cycles are recorded and

maintained in memory. At the 11th recorded

freeze cycle, the rst recorded freeze

cycle time is dropped to maintain the

maximum number of 10 recorded freeze

cycles.

Note: When 1st freeze-time correction cycle

is initiated, CB "POWER OK" LED starts

blinking. On 2nd freeze-time correction cycle,

if CB "POWER OK" LED has been reset,

CB "POWER OK" LED starts blinking. If CB

"POWER OK" had not been reset after 1st

freeze-time correction cycle CB "POWER

OK" LED continues to blink.

After 3rd freeze-time correction cycle in

36hours, CB yellow "EXT HARVEST" LED

starts blinking.

Appliance continues to operate and LEDs

continue to blink until ALARM RESET button

is pressed with power on.

15

B. Service Diagnosis

WARNING

• The appliance should be diagnosed and repaired only by qualied service
personnel to reduce the risk of death, electric shock, serious injury, or re.

• Risk of electric shock. Control switch in "OFF" position does not de-energize all
loads Use extreme caution and exercise safe electrical practices.

• Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.

• Before servicing the appliance, move the control switch to the "OFF" position and
turn off the power supply.

• CHOKING HAZARD: Ensure all components, fasteners, and thumbscrews are
securely in place after the appliance is serviced. Make sure that none have fallen
into the dispenser unit/ice storage bin.

• Make sure all food zones in the appliance and dispenser unit/ice storage bin are
clean after service.

The diagnostic procedure is a sequence check that allows you to diagnose the electrical
system and components. Before proceeding, check for correct installation, proper voltage
per nameplate, and adequate water supply. Check CB using the steps in "II.D. Control
Board Check." Check dip switch settings to assure that S4 dip switches and S5 dip
switches 1 through 5 are in the factory default position. S4 dip switch 1, 2, 3, 4, and 5 are
cleaning adjustments and the settings are exible. For factory default settings, see "III.C.1.
Default Dip Switch Settings."

Note: • When checking high voltage (115VAC), always choose a white (W) neutral wire to

establish a good neutral connection.

• When checking voltage from the CB K1 connector (10 pin connector), pull
CBK1connector out slightly to allow room for multimeter test leads contact.

1) Turn off the power supply, then access the control box. Move the control switch to the
"OFF" position. Clear ice from BC sensing area.

2) Check that the 115VAC 10A fuse is good.

16

1. Sequence and Component Diagnosis

3) Power On: Turn on the power supply, then move the control switch to the "ON"
position and the mode switch to the "ICE" position. A 5-sec. delay occurs. CB red
"POWER OK" LED turns on. If CB yellow "BC OPEN" LED is on (indicating a full
bin), move ice away from BC sensing area.

Note: • CB red "POWER OK" LED remains on unless the 10.5VAC power supply is

interrupted (K2 connector).

• Check CB using the steps in "II.D. Control Board Check" or BC using steps in "II.E.
Bin Control Check and Adjustment."

a) Power On Diagnosis: If CB red "POWER OK" LED is off, conrm 10A fuse is good.

Check for 115VAC at control switch #2 (BK) to neutral (W) then at control switch #1(P)
to neutral (W). If 115VAC is present on #2 (BK) and not on #1(P), replace control
switch. If 115VAC is present on control switch #1 (P), check for 115VAC at HPS (P)
to neutral (W) then HPS (BK) to neutral (W). If115VAC is present at HPS (P) and not
at HPS (BK), HPS is open. See HPS Diagnosis below. If 115VAC is present at HPS
(BK), check for 10.5VAC at CB K2#1 red wire to CB K2 #2 red wire. If 10.5VAC is not
present, check that the cleaning valve is closed and the interlock switch is closed.
Next, check CT continuity. If open, replace CT.

b) HPS Diagnosis: Check that the condenser coil is not clogged or restricted. Let

refrigeration circuit pressures equalize. If HPS does not reset and pressures are
equalized, replace HPS. If pressures are not equalized, reclaim refrigerant and
diagnose refrigeration circuit restriction. Check that there are no restrictions in the
refrigeration circuit.
Harvest Cycle: HGV, strainer, or check valve.
Freeze Cycle: FM, FMR, TXV, WRV, HM, LLV, strainer, check valve, drier, and
damaged line set or tting.

Conrm that the location meets installation requirements:

• The appliance is not intended for outdoor use. Normal operating ambient temperature
should be within 45°F to 100°F (7°C to 38°C).

• Allow 6" (15 cm) clearance at rear, sides, and top for proper air circulation and ease of
maintenance and/or service should they be required.

• The appliance should not be located in a corrosive environment.

4) 1-Min. Fill Cycle – LED 4 is on. WV energizes. After 1 min., CB checks for a closed
FS. If FS is closed, the harvest cycle begins. If harvest cycle begins (Comp, HGV, FMR
energized), continue to step 5a. If FS is open, WV remains energized until FS closes (low
water safety protection during initial start up and at the end of each harvest). Diagnosis:
Check that water enters the water tank. If not, check that the water supply line shut-off
valve is open and screens or external lters are clear. Check for 115VAC at CB K1 #6
(O) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present, and WV
does not energize, check for 115VAC at WV. If 115VAC is present, check coil continuity.
Ifopen, replace WV. If the water tank lls, but the appliance fails to start harvest (Comp
energized), check for open FS. See "II.F. Float Switch Check and Cleaning." If FS is
closed and CB fails to start the harvest cycle after 1 min., replace CB.

17

5a) Initial Harvest Cycle – LEDs 1, 4, and 2 are on. WV continues. Comp, FMR, and

HGV energize. CB monitors the warming of the evaporator via the thermistor located
on the suction line. When the thermistor reaches 48°F (9°C), CB reads 3.9 kΩ from the
thermistor and turns harvest termination over to the harvest timer (S4 dip switch 1 & 2
and S5 dip switch 4). WV are energized during harvest for a maximum of 6 min. or the
length of harvest minus HPT setting (S4 dip switch 6), whichever is shorter. See step 5b
below.

a) Comp Diagnosis: Check that evaporator is warming. Ifnot, conrm that Comp

energizes. If not, check for 115VAC at CB K1 #9 (Y) to neutral (W). If 115VAC is not
present, check for 115VAC at CB K1 #10 (BK) to neutral (W). If115VAC is present
at #10 (BK) and not at #9 (Y), replace CB. If 115VAC is present, check for 115VAC
at mode switch #2 (Y) to neutral and mode switch #1 (V) to neutral. If 115VAC is
present at #2 (Y) and not at #1 (V), conrm mode switch is in "ICE" position. If in
"ICE" position, check mode switch continuity. If open, replace mode switch. If 115VAC
is present at mode switch #1 (V), check for 115VAC at CR solenoid. If 115V AC is
present, conrm contacts are closed. If not, replace CR. If CR contacts are closed,
check Comp external overload, Comp start and run capacitors, Comp start relay, and
Comp motor winding.

b) HGV Diagnosis: If Comp is energized and evaporator is not warming, check that

HGV energizes and opens. Check for 115VAC at CB K1 #2 (P) to neutral (W).
If115VAC is not present, check for 115VAC at CB K1 #1 (V). If 115VAC is not present,
check wiring for loose connection from CB 10 pin connector pin #1 (V) to mode
switch. If 115VAC is present on #1 (V) and not at #2 (Y), replace CB.
If 115VAC is present at #2 (Y), check for 115VAC at HGV coil and check HGV coil
continuity. Replace as needed. Note: LED is off when HGV is energized and on when
LLV/FM are energized.

c) LLV Diagnosis: Conrm that LLV is de-energized and closed (not bypassing).

Ifenergized, replace CB. If de-energized and bypassing, replace LLV.

d) WRV Diagnosis: Conrm WRV is not leaking by. If WRV is leaking by, conrm HGV

is open and LLV is closed. Next, check for proper refrigerant pressures. If refrigerant
pressures are correct, adjust or replace WRV. See "IV.C. Water Regulating Valve
Adjustment (water-cooled models).".

5b) Harvest Pump Time (Harvest Assist) – LEDs 1 and 3 are on. When the thermistor

reaches 48°F (9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination
over to the harvest timer (S4 dip switch 1 & 2 and S5 dip switch 4).
When WV de-energizes, LED 4 turns off and LED 3 turns on. PM energizes. Comp,
FMR, and HGV continue.
Diagnosis: Place a thermometer on the suction line next to the thermistor. Has it
warmed to 48°F (9°C) or warmer? Conrm thermistor status. See "II.G Thermistor
Check." If the thermistor reading is in proper range, dip switch 7 is on, and PM does not
energize before harvest terminates, replace CB. If WV continues, check for 115VAC at
CB K1 #6 (O). If115VAC is present, and LED 4 is off, replace CB. If LED 3is on and PM
is not energized, check for 115VAC at CB K1 #4(R). If115VAC is not present, replace
CB. If 115VAC is present and PM is not energized, check PM capacitor and motor
winding continuity.

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5c) Initial Harvest Cycle Termination Diagnosis: When the thermistor reaches 48°F

(9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination over to
the harvest timer (S4 dip switch 1 & 2 and S5 dip switch 4). Check discharge line
temperature. For a thermistor check, see "II.G.Thermistor Check." If 1-min. ll cycle
starts after harvest timer terminates, check that FS is clean and operating properly, see
"II.F. Float Switch Check and Cleaning." If FS is closed, CB proceeds to the next cycle.
Ifnot, replace CB.
Note: The minimum total time allowed by CB for a complete harvest cycle is based on
S5 dip switch 4. Maximum harvest time allowed is 20 min.

NOTICE! S4 dip switch 7 must remain on. Otherwise, PM will not energize during
the last seconds of harvest.

6) Freeze Cycle – LED 1, 2, and 3 are on. Comp, FMR, and PM continue. FM and
LLV energize. HGV de-energizes. Appliance is held in freeze by a 5-min. short cycle
protection timer. After 5-min. short cycle protection timer terminates and FS opens,
freeze cycle terminates.
Note: PM power supply continues from CB K1 #4 (R) in harvest and in freeze.
Anti-Slush: When anti-slush is enabled (S5 dip switch 5 "ON"), PM de-energizes when
thermistor reaches 36°F (2.2°C) (5.8 kΩ) for 10 sec. then, energizes for the remainder
of the freeze cycle.

a) Freeze Cycle Diagnosis: Conrm Comp, FMR, and PM continue. Conrm that FM

and LLV energize. Conrm WRV opens. Next, conrm HGV de-energizes.
During the rst 5 min. of freeze, conrm evaporator is cooling. If not, conrm
WV de-energized (not leaking by), HGV de-energized (not bypassing), LLV and
FM energize, TXV and HM operate correctly, WRV opens, Comp is efficient, and
refrigerant charge is correct. See "VIII.A. Specication and Performance Data
Sheets."

b) Comp and FMR Diagnosis: If Comp and FMR de-energize once freeze begins,

check that appliance has not shut off on HPS (CB "POWER OK" LED off). If so,
check "3)b) HPS Diagnosis" above. If CB "POWER OK" LED is on, check for 115VAC
at CB K1 #9 (Y) to neutral (W). If 115VAC is not present and LED 1 is on, replace CB.
If 115VAC is present, check for 115VAC at CR coil. If 115VAC is present, check CR
coil and contact continuity. Replace as needed. If CR is okay, check Comp start relay
and start and run capacitors. Next, check Comp motor winding continuity. If Comp is
energized but evaporator is not cooling, check for an inefficient Comp.
See "VIII.A. Specication and Performance Data Sheets." If Comp is energized but
FMR is not, check for 115VAC at the FMR junction box. If 115VAC is not present,
check icemaker wiring connections. If 115VAC is present, check for voltage at
condenser unit. If115VAC is not present, check eld wiring connections. If 115VAC is
present, check FMR capacitor, motor winding, and fan blade for binding.

c) WV and HGV Diagnosis: If WV is energized, check for 115VAC at CB K1 #6 (O)

to neutral (W). If 115VAC is present after PM energizes in harvest cycle, replace
CB. If 115VAC is not present, replace WV (bypassing). If HGV did not de-energize
at the end of harvest, check for 115VAC at CB K1 #2 (P) to neutral (W). If 115VAC
is present and LED 2 is on, replace CB. If 115VAC is not present, replace HGV
(bypassing).

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