Hoshizaki KM-901MAJ, KM-901MWJ, KM-1100MAJ, KM-1100 MWJ Service Manual

Service Manual

Modular Crescent Cuber

Models
KM-901MAJ, MWJ, MRJ/3
KM-1100MAJ, MWJ, MRJ
KM-1340MAJ, MWJ, MRJ/3
KM-1601MRJ/3

hoshizakiamerica.com

Number: 73213
Issued: 1-30-2018
Revision: 9-18-2018

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/3) .......................................................................................... 9

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

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

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

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

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

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

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

C. Freeze-Time Correction Cycle (90 min.) (Control Board 2A7664-02) .......................... 23

D. Control Board Check ................................................................................................... 25

E. Bin Control Check ....................................................................................................... 26

F. Float Switch Check and Cleaning ................................................................................ 27

1. Float Switch Check ................................................................................................ 27

2. Float Switch Cleaning ............................................................................................ 28

G. Thermistor Check ........................................................................................................ 29

H. Control Switch ............................................................................................................. 29

I. Diagnostic Tables .......................................................................................................... 30

J. Freeze-Up Check List .................................................................................................. 34

III. Controls and Adjustments ............................................................................................... 35

A. Control Board Layout .................................................................................................. 36

B. LED Lights and Audible Alarm Safeties ....................................................................... 37

C. Settings and Adjustments ............................................................................................ 38

1. Default Dip Switch Settings .................................................................................... 38

2. Harvest Timer (S4 dip switch 1 & 2) ...................................................................... 39

3. Pump-Out Timer/Harvest Time During Pump-Out (S4 dip switch 3 & 4) ............... 39

4. Pump-Out Frequency Control (S4 dip switch 5) ..................................................... 40

5. Harvest Pump Time (Harvest Assist) (S4 dip switch 6) ......................................... 40

6. Harvest Pump Time (Harvest Assist)/Freeze-Time Correction (S4 dip switch 7) .. 41

7. Factory Use (S4 dip switch 8)................................................................................. 41

8. Freeze Timer (S4 dip switch 9 & 10) ...................................................................... 42

9. Float Switch Selector (S5 dip switch 1) ................................................................. 42

10. Rell Counter (S5 dip switch 2 and 3) .................................................................. 42

11. Minimum Harvest Time (S5 dip switch 4) ............................................................. 43

12. Anti-Slush (S5 dip switch 5) ................................................................................. 43

D. Control Switch ............................................................................................................. 43

3

IV. Refrigeration Circuit and Component Service Information.............................................. 44

A. Refrigeration Circuit Service Information .................................................................... 44

B. Component Service Information .................................................................................. 47

C. Water Regulating Valve Adjustment (water-cooled model) .......................................... 47

V. Maintenance .................................................................................................................... 48

VI. Preparing the Appliance for Periods of Non-Use ............................................................ 49

VII. Disposal ......................................................................................................................... 51

VIII. Technical Information .................................................................................................... 52

A. Specication and Performance Data Sheets ............................................................... 52

1. KM-901MAJ ............................................................................................................ 52

2. KM-901MWJ .......................................................................................................... 53

3. KM-901MRJ with URC-14F ................................................................................... 54

4. KM-901MRJ3 with URC-14F ................................................................................. 55

5. KM-1100MAJ ......................................................................................................... 56

6. KM-1100MWJ ........................................................................................................ 57

7. KM-1100MRJ with URC-14F .................................................................................. 58

8. KM-1340MAJ ......................................................................................................... 59

9. KM-1340MWJ ........................................................................................................ 60

10. KM-1340MRJ with URC-14F ............................................................................... 61

11. KM-1340MRJ3 with URC-14F .............................................................................. 62

12. KM-1601MRJ with URC-22F ................................................................................ 63

13. KM-1601MRJ3 with URC-22F .............................................................................. 64

B. Wiring Diagrams ......................................................................................................... 65

1. KM-901M_J, KM-1100M_J ..................................................................................... 65

2. KM-1340M_J and KM-1601MRJ ............................................................................ 66

3. KM-901MRJ3 ......................................................................................................... 67

4. KM-1340MRJ3 and KM-1601MRJ3 ....................................................................... 68

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)

Spray Tubes

Inlet Water Valve

Cleaning Valve

Control Switch

Hot Gas Valve

Water Supply Inlet

Thermostatic
Expansion Valve

Condenser

Fan Motor

Float Switch

Water Pump

Control Box

Compressor

Model Shown: KM-901MAJ

High-Pressure
Switch

Drier

Liquid Line Valve

7

2. Water-Cooled Models (MWJ)

Spray Tubes

Inlet Water Valve

Cleaning Valve

Control Switch

Float Switch

Hot Gas Valve

Water Supply Inlet

Thermostatic
Expansion Valve

Water
Regulating
Valve

Condenser

Water Pump

Control Box

Compressor

High-Pressure Switch

Drier

Liquid Line Valve

Model Shown: KM-1100MWJ

8

3. Remote Models (MRJ/3)

Spray Tubes

Inlet Water Valve

Cleaning Valve

Control Switch

Hot Gas Valve

Water Supply Inlet

Junction Boxes

Thermostatic
Expansion Valves

Control Box

Float Switch

Water Pump

Crankcase
Heater

Receiver Tank

Main Transformer

Drier

Liquid Line Valve

Compressor

Model Shown: KM-1601MRJ

9

B. Water/Refrigeration Circuit Diagram

1. Air-Cooled Models (MAJ)

Spray Tubes

Inlet Water Valve

Condenser

Drier

Water Supply

Float Switch

Drain

Water
Tank

Evaporator

Thermistor

Water Pump

Pump Out

Freeze

Fan

Liquid Line Valve

Heat
Exchanger

Suction Line

Compressor

High-Pressure
Switch

Strainer

Hot Gas
Val ve

Discharge Line

Refrigeration Circuit

Water Circuit

Thermostatic Expansion Valve

Check Valve

10

2. Water-Cooled Models (MWJ)

Spray Tubes

Inlet Water Valve

Water Regulating Valve

Condenser

Water Supply

Float Switch

Drain

Water
Tank

Evaporator

Thermistor

Water Pump

Pump Out

Freeze

Liquid Line Valve

Heat
Exchanger

Suction Line

Compressor

Drier

High-Pressure
Switch

Strainer

Hot Gas
Val ve

Discharge Line

Refrigeration Circuit

Water Circuit

Thermostatic Expansion Valve

Check Valve

11

3. Remote Models (MRJ/3)

Inlet Water Valve

Condenser

Fan

Headmaster
(C.P.R.)

Spray Tubes

Access
Val ve

Water Supply

Cleaning Valve

Float Switch

Drain

Water
Tank

Thermistor

Water Pump

Freeze Pump-Out

Receiver

Evaporator

Liquid Line
Val ve

Heat
Exchanger

Suction Line

Compressor

Drier

High-Pressure
Switch

Strainer

Hot Gas
Val ve

Check Valves

Discharge Line

Refrigeration Circuit

Water Circuit

Thermostatic Expansion
Val ve

Check Valve

12

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

FM*/FMR energized

HGV energized

PM de-energizes for 2 sec.,

then reverses for 10/20 sec.

FM* de-energized

LLV de-energized

CB: 2A7664-02

When freeze time differential exceeded,

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.

• Factory set for every 10th

4. Pump-Out Cycle

freeze-time correction cycle starts.

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

FS closed

50 sec.

Comp energized

FM energized

FMR energized

PM energized

LLV energized

HGV de-energized

FS check

FS open

3. Freeze Cycle

• Min. freeze time: 5 min.

• Max. freeze time: freeze timer setting (S4

dip switch 9 & 10).

5-min.

minimum

freeze timer in

Harvest Pump

control

Time

Operation Flow Chart

PM energized

WV de-energized

FS closed

Thermistor temperature reaches

Comp energized

FM*/FMR energized

48°F (9°C) (3.9 kΩ or less). Harvest

HGV energized

FM* – FM energized in 2. Harvest Cycle and

4. Pump-Out Cycle when connected to CB K1

timer starts.

WV energized

connector pin #9.

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

The "WASH" position on the control switch is used when cleaning and sanitizing the unit. When in the "WASH" position, power is supplied

to the pump motor. With the cleaning valve closed, the cleaner and sanitizer ow over the outside of the evaporator plate assembly. With the

cleaning valve open, the cleaner and sanitizer ow over both the outside and the inside of the evaporator plate assembly.

Note: Close the cleaning valve after cleaning and sanitizing are complete, otherwise the unit will not restart when the control

switch is placed in the "ICE" position.

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

2. Harvest Cycle

1 to 3-min. harvest timer in

control (S4 dip switch 1 & 2)

Thermistor

in control

setting (S4 dip switch 6), whichever is shorter.

• Max. harvest time: 20 min.

WV energized

13

FS open

If FS is open, Comp stops and cycle

returns to 1-Min. ll.

Legend:

BC–bin control

CB–control board

Comp–compressor

FM*–fan motor

FMR–fan motor-remote

FS–oat switch

HGV–hot gas valve

HPT–harvest pump time

LLV –liquid line valve

PM–pump motor

WV–inlet water valve

Fill Cycle

FS check

1. 1-Minute

Cycle

Steps

Startup

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 actuator paddle disengaged)

Green "BC CLOSED" LED on

Yellow "BC OPEN" LED off

Yellow "BC OPEN" LED continues. All

components de-energized.

Shutdown Flow Chart

Control board 2A7664-02 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.

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

BC open (BC actuator paddle engaged)

Green "BC CLOSED" 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

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

WV energized

2A7664-02 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

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:

Cycle.

Differential

Value in Sec.

3 254

4 309

5 349

6 380

7 406

8 427

9 446

10 462

CB yellow "EXT HARVEST: LED turns off.

Number of

Freeze Time Differential Exceeded.

Minimum and Maximum Freeze times have

exceeded differential parameters.

Freeze-Time Correction function is enabled

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

CB monitors freeze time. After 3freeze

cycles, CB compares the minimum and

maximum differential of the 3 freeze cycle

times. Every freeze cycle time after the third

freeze cycle time is added to the minimum/

maximum calculation.

Example: After 8 cycles, if the differential

between the shortest cycle (minimum) and

the longest cycle (maximum) is equal to or

greater than 427 sec. a freeze-time correction

cycle is initiated:

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: • On 208-230/60/1 models with main transformer and 208-230/60/3 models,

the appliance neutral (W) is provided through the main transformer. To conrm
a good neutral, check for 60VAC from white (W) neutral to ground (GND).
If60VAC is present, neutral is good. If 60VAC is not present, check 208-230VAC
main power supply to main transformer. If 208-230VAC is present, check main
transformer continuity.

• 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 any ice from BC bulb.

2) Check that BC is closed and 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 "ICE" position.
A 5-sec. delay occurs. CB red "POWER OK" LED and CB green "BC CLOSED" LED
turn on. If CB yellow "BC OPEN" LED is on (indicating a full bin), check CB K4 red
jumper. Move ice away from BC bulb.

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."

• Conrm CB green "BC CLOSED" LED is on. If CB yellow "BC OPEN" LED is on,
conrm CB K4 jumper is in place. Otherwise, CB yellow "BC OPEN" LED is on
and appliance will not start.

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

Check for 115VAC at control switch #1 (BR) to neutral (W) then at control switch
#2(P) to neutral (W). If 115VAC is present on #1 (BR) and not on #2(P), replace
control switch. If 115VAC is present on control switch #2 (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.

17

4) 1-Min. Fill Cycle – LED 4 is on. WV and X11 relay energize. After 1 min., CB checks for
a closed FS. If FS is closed, the harvest cycle begins. If harvest cycle begins (Comp,
HGV, FM*, 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.

5a) Initial Harvest Cycle – LEDs 1, 4, and 2 are on. WV and X11 relay continue. Comp,

FM* (if connected to CB K1 connector pin #9), FMR, HGV, and X10 relay 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 and X11 relay 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 #1 or #9 (V) to neutral (W). If 115VAC is
not present, check for 115VAC at CB K1 #7 or #10 (BR) to neutral (W). If115VAC is
present at #7 or #10 (BR) and not at #1 or #9 (V), replace CB. If 115VAC is present,
check for 115VAC at CR or MC solenoid. If 115VAC is present, conrm contacts are
closed. If not, replace CR or MC. If CR or MC 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, replace CB. If 115VAC is present, check for 115VAC at HGV
coil and check HGV coil continuity. Replace as needed.

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).

18

5b) Harvest Pump Timer – LEDs 1, 3, and 2 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, X11 relay de-energizes and LED 3 turns on. PM energizes. Comp, FM*,
FMR, HGV, and X10 relay 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 #5(DBU). If115VAC is not
present, replace CB. If 115VAC is present and PM is not energized, check for 115VAC
at X10relay terminal #7 (Y) to neutral (W). If 115VAC is not present, check for 115VAC
at X10 relay terminal #3 (P) to neutral (W) and X10 relay terminal #5 (Y) to neutral (W).
If 115VAC is present on terminal #3(P) and not on terminal #5 (Y), replace X10 relay.
If 115VAC is present on X10 relay terminal #7 (Y) and PM is not energized, check for
115VAC at X10 relay terminal #4 (R) to neutral (W) and terminal #6 (DBU) to neutral
(W). If 115VAC is present on terminal #6(DBU) and not on terminal #4 (R), replace
X10relay. If 115VAC is present on X10relay terminal #4 (R), check control switch
contact continuity between terminals #4(R) and #5(W/R). Ifcontacts are open, replace
control switch. If contacts are closed and 115VAC is present between control switch
terminal #5 (W/R) and neutral (W), check PM capacitor and motor winding continuity.

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 is on. Comp, FM*, FMR, and PM continue. FM and LLV
energize. HGV and X10 relay de-energize. 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 switches from CBK1 #5(DBU) in harvest to K1 #4 (R) 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) (5.8kΩ) for 10 sec. then, energizes for the remainder of
the freeze cycle.

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

that FM and LLV energize. Conrm WRV opens. Next, conrm HGV and X10 relay
de-energize. 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, FM*, and FMR Diagnosis: If Comp, FM*, and FMR de-energize once freeze

begins, check that appliance has not shut off on HPS ("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 #1 (V) or #9 (V) to neutral (W). If 115VAC is not present and LED 1 is on,
replace CB. If 115VAC is present, check for 115VAC at CR or MC coil. If 115VAC is
present, check CR or MC coil and contact continuity. Replace as needed. If CR or
MC 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."
FM* Diagnosis: If Comp is energized but FM* is not, check CB K1 #1 (V) and #9
(V) wiring circuit for loose connection. If connections are good, check FM* capacitor,
motor winding, and blade for binding.
FMR Diagnosis: 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 50 sec. after PM energizes, replace CB. If 115VAC is not present, replace
HGV (bypassing).

d) PM Diagnosis: Conrm water is owing over evaporator from PM and not WV. If PM

de-energizes once freeze begins, check for 115VAC at CB K1 #4 (R) to neutral (W).
If 115VAC is not present, replace CB. If 115VAC is present and PM is de-energized,
check for 115VAC at control switch #5 (W/R) to neutral (W). If 115VAC is present at
CB K1 #4 (R) and not at control switch #5 (W/R), check control switch continuity
between #5 (W/R) and #4 (R). Replace as needed. If 115VAC is present at control
switch #5 (W/R) to neutral (W), check PM capacitor and motor winding continuity.

e) FM and LLV Diagnosis: If FM or LLV does not energize, check for 115VAC at CB

K1#3 (BK) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present:
For FM, check capacitor, motor winding, and blade for binding.
For LLV, check coil voltage and continuity.

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f) Refrigerant Pressures, HM, and TXV Diagnosis: If evaporator is still not cooling,

check refrigerant pressures. See "VIII.A. Specication and Performance Data
Sheets."
Next, check HM operation. If refrigeration pressures are above HM setpoint and
HMis bypassing, replace HM. Check TXV for proper operation. Remove TXV bulb
and hold it in your hand, refrigerant low-side pressure should rise, place TXV bulb in
ice water, refrigerant low-side pressure should drop. A 10 to 15 pound pressure swing
between warm and cold conditions indicate a good TXV. If a 10 to 15 pound swing is
not present, replace TXV.

g) WRV Diagnosis: WRV is factory set and generally no adjustment is required.

IfWRV fails to open in freeze, check for proper refrigerant pressures. See "VIII.A.
Specication and Performance Data Sheets." If refrigerant pressures are correct and
WRV does not open, adjust or replace as needed. See "IV.C. Water Regulating Valve
Adjustment (water-cooled models)."

h) Freeze Termination Diagnosis: After 5 min. in freeze, disconnect CB K5 FS

connector. 15 sec. later appliance should switch out of the freeze cycle (15 second
delay after FS opens before terminating the freeze cycle). If appliance remains in
freeze longer than 15 sec. after FS removed, replace CB. If appliance switches with
FS removed but would previously not switch out of freeze with FS connected (long
freeze - 3 beep alarm), see "II.F. Float Switch Check and Cleaning."

Note: Normal freeze cycle will last 20 to 40 min. depending on model and conditions.

Cycle times and pressures should follow performance data provided in this
manual. See "VIII.A. Specication and Performance Data Sheets."

i) Short Freeze Cycle Diagnosis: Conrm water tank lls and overows during 1 min.

ll and harvest cycles. If not, check water supply lters, shut-off valve, WV screen.
Ifwater tank empties before 5 min. timer terminates and freeze cycle is short, check
that CV is not leaking by (water owing down the potable drain). If CV is leaking by,
remove and clean CV, replace rubber seat and spring if necessary. If water tank is
full, see "II.F. Float Switch Check and Cleaning." for erratic operating FS.

7) Pump-Out Cycle – LEDs 1, 3, and 2 are on (10/20 second pump-out). Timing of the
rst pump-out is determined by S4 dip switch 5. See the table below.

Control Board Settings

S4 Dip Switch Setting

No. 5

OFF Every 10 cycles After 11th freeze cycle

ON Every cycle After 2nd freeze cycle

Pump-Out Frequency Control Board

Comp, FM*, and FMR continue, HGV energize.
Note: If S4 dip switch 3 & 4 are set to 3 off and 4 on, LED 4 turns on and WV and X11
relay energize, energizing X10 relay. NOTICE!S4dip switch 3 & 4 must not be set

to 3 off and 4 on. Otherwise, PM will rotate in freeze cycle direction instead of
pump-out direction.

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