Hoshizaki KM-320MAH, MWH, MRH KM-600MAH, MWH KM-515MAH, MWH-M User Manual

Hoshizaki

Hoshizaki America, Inc.

Modular Crescent Cuber

Models
KM-320MAH, MWH

“A Superior Degree

of Reliability”

www.hoshizaki.com

KM-515MAH, MWH, MRH
KM-600MAH
KM-650MAH, MWH(-M), MRH
KM-901MAH, MWH, MRH/3

SERVICE MANUAL

Number: 73196
Issued: 4-29-2013

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]

HOSHIZAKI AMERICA, INC.
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 ................................................................................................. 6

I. Construction and Water/Refrigeration Circuit Diagram ....................................................... 8

A. Construction .................................................................................................................. 8

1. Air-Cooled Models (MAH) ........................................................................................ 8

2. Water-Cooled Models (MWH(-M)) ........................................................................... 9

3. Remote Models (MRH/3) ....................................................................................... 10

B. Water/Refrigeration Circuit Diagram .............................................................................11

1. Air-Cooled Models (MAH) .......................................................................................11

2. Water-Cooled Models (MWH(-M)) ......................................................................... 12

3. Remote Models (MRH/3) ....................................................................................... 13

II. Sequence of Operation and Service Diagnosis ............................................................... 14

A. Sequence of Operation Flow Chart ............................................................................. 14

1. "E" and "G" Control Board without Harvest Pump Timer Operation ....................... 14

2. "G" Control Board with Harvest Pump Timer Operation ....................................... 16

B. Service Diagnosis ....................................................................................................... 17

1. "E" and "G" Control Board without Harvest Pump Timer Diagnosis ....................... 18

2. "G" Control Board with Harvest Pump Timer Diagnosis ........................................ 24

C. Control Board Check ................................................................................................... 30

D. Bin Control Check ....................................................................................................... 31

1. Thermostatic Bin Control Check ............................................................................ 31

2. Mechanical Bin Control Check and Cleaning ....................................................... 32

E. Float Switch Check and Cleaning ............................................................................... 34

1. Float Switch Check ................................................................................................ 34

2. Float Switch Cleaning ............................................................................................ 35

F. Thermistor Check ......................................................................................................... 36

G. Diagnostic Tables ........................................................................................................ 37

III. Controls and Adjustments ............................................................................................... 41

A. Control Board Layout .................................................................................................. 42

1. "E" Control Board .................................................................................................. 42

2. "G" Control Board ................................................................................................. 43

B. LED Lights and Audible Alarm Safeties ....................................................................... 44

1. "E" Control Board .................................................................................................. 44

2. "G" Control Board ................................................................................................. 45

C. Settings and Adjustments ............................................................................................ 46

1. Default Dip Switch Settings .................................................................................... 46

a) "E" and "G" Control Board without Harvest Pump Timer Operation .................. 46

b) "G" Control Board with Harvest Pump Timer Operation .................................... 46

2. Harvest Timer (S4 dip switch 1 & 2) ...................................................................... 47

3. Pump-Out Timer (S4 dip switch 3 & 4) .................................................................. 47

4. Pump-Out Frequency Control (S4 dip switch 5 & 6) .............................................. 48

3

5. Bin Control Selector or Harvest Pump Timer Operation (S4 dip switch 7) ............. 48

6. Factory Use (S4 dip switch 8) ................................................................................ 49

7. Freeze Timer (S4 dip switch 9 & 10) ....................................................................... 49

8. Float Switch Selector (S5 dip switch 1): "G" Control Board ................................... 50

9. Rell Counter (S5 dip switch 2 through 5): "G" Control Board ............................... 50

D. Control Switch ............................................................................................................. 50

IV. Refrigeration Circuit and Component Service Information.............................................. 51

A. Refrigeration Circuit Service Information .................................................................... 51

B. Component Service Information .................................................................................. 54

C. Water Regulating Valve Adjustment (water-cooled model) .......................................... 54

V. Maintenance .................................................................................................................... 55

VI. Preparing the Appliance for Periods of Non-Use ............................................................ 56

VII. Disposal ......................................................................................................................... 58

VIII. Technical Information .................................................................................................... 59

A. Specication Sheets.................................................................................................... 59

1. KM-320MAH........................................................................................................... 59

2. KM-320MWH ......................................................................................................... 60

3. KM-515MAH .......................................................................................................... 61

4. KM-515MWH ......................................................................................................... 62

5. KM-515MRH .......................................................................................................... 63

6. KM-600MAH .......................................................................................................... 64

7. KM-650MAH ........................................................................................................... 65

8. KM-650MWH ......................................................................................................... 66

9. KM-650MWH-M ..................................................................................................... 67

10. KM-650MRH ........................................................................................................ 68

11. KM-901MAH ......................................................................................................... 69

12. KM-901MWH ....................................................................................................... 70

13. KM-901MRH ........................................................................................................ 71

14. KM-901MRH3 ...................................................................................................... 72

B. Performance Data ....................................................................................................... 73

1. KM-320MAH .......................................................................................................... 73

2. KM-320MWH ..........................................................................................................74

3. KM-515MAH .......................................................................................................... 75

4. KM-515MWH ......................................................................................................... 76

5. KM-515MRH .......................................................................................................... 77

6. KM-600MAH .......................................................................................................... 78

7. KM-650MAH ........................................................................................................... 79

8. KM-650MWH ......................................................................................................... 80

9. KM-650MWH-M ..................................................................................................... 81

10. KM-650MRH ........................................................................................................ 82

11. KM-901MAH ......................................................................................................... 83

12. KM-901MWH ....................................................................................................... 84

13. KM-901MRH ........................................................................................................ 85

14. KM-901MRH3 ...................................................................................................... 86

4

C. Wiring Diagrams ......................................................................................................... 87

1. Diagrams Without Harvest Pump Timer Relays ..................................................... 87

a) KM-320M_H, KM-515M_H, KM-600MAH ........................................................ 87

b) KM-650MAH, KM-650MWH, KM-901MAH, KM-901MWH ............................... 88

c) KM-650MRH, KM-901MRH .............................................................................. 89

d) KM-901MRH3 .................................................................................................. 90

2. Diagrams With Harvest Pump Timer Relays .......................................................... 91

a) KM-515MAH .................................................................................................... 91

b) KM-650MAH, KM-650MWH, KM-901MAH ...................................................... 92

c) KM-650MWH-M ............................................................................................... 93

d) KM-650MRH .................................................................................................... 94

5

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. Failure to meet these code requirements could result in
death, electric shock, serious injury, re, or damage to the appliance.

• 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 appliance 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.

• Before servicing the appliance, move the control switch to the "OFF" position and

turn off the power supply. 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.

6

WARNING, continued

• 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.

• 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 wire 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 appliance on during extended periods of non-use, extended

absences, or in sub-freezing temperatures. To properly prepare the appliance 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.

7

I. Construction and Water/Refrigeration Circuit Diagram

A. Construction

1. Air-Cooled Models (MAH)

Thermostatic
Expansion Valve

Spray Tubes

Inlet Water Valve

Thermostatic
Bin Control

Cleaning Valve

Control Switch

Float Switch

Water Pump

Control Box

Water Supply Inlet

Hot Gas Valve

Condenser

Fan Motor

High-Pressure
Switch

Drier

Liquid Line Valve
KM-515MAH

Thermostatic Bin Control
Bracket & Bulb Holder

Compressor

Mechanical Bin Control and Bracket

Model Shown: KM-515MAH

8

2. Water-Cooled Models (MWH(-M))

Spray Tubes

Inlet Water Valve

Thermostatic
Bin Control

Cleaning Valve

Control Switch

Float Switch

Water Pump

Thermostatic
Expansion Valve

Main Transformer
KM-650MWH-M

Water Supply Inlet

Hot Gas Valve

High-Pressure Switch

Water Regulating
Valve

Condenser

Control Box

Liquid Line Valve
KM-320MWH and
KM-515MWH

Drier

Compressor

Thermostatic Bin Control
Bracket & Bulb Holder

Mechanical Bin Control and Bracket

Model Shown: KM-515MWH

9

3. Remote Models (MRH/3)

Spray Tubes

Inlet Water Valve

Cleaning Valve

Control Switch

Thermostatic
Expansion Valves

Water Supply Inlet

Hot Gas Valve

Junction Boxes

Thermostatic
Bin Control

Float Switch

Water Pump

Compressor

Thermostatic Bin Control
Bracket & Bulb Holder

Control Box

Receiver Tank

Drier

Liquid Line Valve

Mechanical Bin Control and Bracket

Model Shown: KM-901MRH

10

B. Water/Refrigeration Circuit Diagram

1. Air-Cooled Models (MAH)

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
(KM-515MAH)

Heat
Exchanger

Suction Line

Compressor

High-Pressure
Switch

Strainer

Hot Gas
Val ve

Discharge Line

Refrigeration Circuit

Water Circuit

Thermostatic Expansion Valve

Check Valve

11

2. Water-Cooled Models (MWH(-M))

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
(KM-320MWH and
KM-515MWH)

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

12

3. Remote Models (MRH/3)

Spray Tubes

Inlet Water Valve

Condenser

Fan

Headmaster
(C.P.R.)

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
(KM-901MRH)

Discharge Line

Refrigeration Circuit

Water Circuit

Thermostatic Expansion
Val ve

Check Valve

13

II. Sequence of Operation and Service Diagnosis

A. Sequence of Operation Flow Chart

1. "E" and "G" Control Board without Harvest Pump Timer Operation

10th cycle

(except KM-515M_H)

(S4 dip switch 5 & 6)

2 sec., then reverses

for 10/20 sec. (S4 dip

• Factory set for every

4. Pump-Out Cycle

• Pump motor stops for

switch 3 & 4)

FS in control

Comp continues

FMR continues

FS opens or

freeze timer

terminates

HGV energized

WV energized (KM-320M_H S4 dip

switch 3 & 4)

PM de-energizes for 2 sec.,

then reverses for 10/20 sec.

FM de-energized

LLV de-energized

3. Freeze Cycle

2. Harvest Cycle

• Minimum freeze time: 5 min.

• Maximum freeze time: freeze

• Maximum inlet water valve time: 6 min.

• Maximum harvest time: 20 min.

timer setting

(S4 dip switch 9 & 10)

5-min. minimum

freeze timer in

1 to 3-min. harvest

timer in control

Thermistor in

control

control

(S4 dip switch 1 & 2)

FS closed

Comp continues

FS check

Thermistor temperature

FS closed

Comp energized

FS check

FMR continues

FM energized

LLV energized

PM energized

HGV de-energized

WV de-energized

FS open

reaches 48°F (9°C) (3.9 kΩ

or less). Harvest timer starts

(1 to 3 min.).

FMR energized

HGV energized

WV energized

FS open

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 icemaker. 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 icemaker will not restart when the

control switch is placed in the "ICE" position.

See next page.

Startup

WV energized

If FS is open, Comp stops and cycle returns to 1-min. ll.

Legend:

Comp–compressor

FM–fan motor

FMR–fan motor-remote

FS–oat switch

HGV–hot gas valve

LLV–liquid line valve

PM–pump motor

WV–inlet water valve

Shutdown and Restart

1. 1-Minute

Fill Cycle

"E" and "G" Control Board Without Harvest Pump Timer Operation Flow Chart

Cycle

Steps

14

To 1. 1-Minute Fill Cycle

Icemaker starts at

"1. 1-Minute Fill Cycle."

3. Ice Level Lowered

MBC closed

(MBC actuator paddle disengaged)

Green "BC CLOSED" LED on

Yellow "BC OPEN" LED off

2. Icemaker Off

All components

de-energized.

To 1. 1-Minute Fill Cycle

Yellow "BC OPEN" LED continues. All

components de-energized.

"E" and "G" Control Board Without Harvest Pump Timer Operation Flow Chart, Continued

3. Ice Level Lowered

No ice touching

TBC bulb.

Icemaker starts at

"1. 1-Minute Fill Cycle."

TBC closed

2. Icemaker Off

All components

1. Bin Full

de-energized.

Within 10 sec.

after ice contacts

TBC bulb,

icemaker shuts

down.

TBC open

All components

de-energized

Ice contacts TBC bulb

1. Bin Full

Shutdown Delay:

• Fill Cycle–15 sec. after activation.

• Harvest Cycle–At the end of the harvest cycle, or up to 15 sec. into the

freeze cycle if activated at the end of the harvest cycle.

the 5-min. short cycle protection timer terminates.

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

Otherwise, at the end of the next harvest cycle.

MBC open (MBC actuator paddle engaged)

Green "BC CLOSED" LED off

Yellow "BC OPEN" LED on

Mechanical Bin Control Shutdown Sequence Flow Chart

Shutdown

TBC

Shutdown

Thermostatic Bin Control Shutdown Sequence Flow Chart

and Restart

Operation

and Restart

MBC Operation

15

Legend:

MBC–mechanical bin control

TBC–themostatic bin control

2. "G" Control Board with Harvest Pump Timer Operation

10th cycle

(except KM-515M_H)

(S4 dip switch 5 & 6)

2 sec., then reverses

for 10/20 sec.

4. Pump-Out Cycle

3. Freeze Cycle

• Factory set for every

• Minimum freeze time: 5 min.

• Maximum freeze time: freeze timer

setting (S4 dip switch 9 & 10)

• Pump motor stops for

(S4 dip switch 3 & 4)

FS in control

5-min. minimum

freeze timer in

Comp continues

FMR continues

HGV energized

PM de-energizes for 2 sec.,

then reverses for 10/20 sec.

FM de-energized

LLV de-energized

Icemaker starts at

"1. 1-Minute Fill Cycle."

3. Ice Level Lowered

FS opens or

freeze timer

terminates

2. Icemaker Off

All components

de-energized.

control

FS closed

Comp continues

FMR continues

FM energized

LLV energized

PM energized

HGV de-energized

To 1 above

MBC closed

(MBC actuator paddle disengaged)

Green "BC CLOSED" LED on

Yellow "BC OPEN" LED off

Yellow "BC OPEN" LED continues. All

FS check

50 sec.

Harvest Pump

Timer

PM energized

WV de-energized

1 to 3-min. harvest timer in

control (S4 dip switch 1 & 2)

Thermistor temperature reaches

FS closed

Comp energized

FMR energized

HGV energized

2. Harvest Cycle

Thermistor in

control

• Maximum inlet water valve time: 6 min. or the length of

harvest minus 50 sec. (S4 dip switch 7), whichever is shorter.

• Maximum harvest time: 20 min.

"G" Control Board With Harvest Pump Timer Operation Sequence Flow Chart

FS check

1. 1-Minute

Fill Cycle

WV energized

48°F (9°C) (3.9 kΩ or less). Harvest

WV energized

FS open

FS open

timer starts (1 to 3 min.).

freeze cycle if activated at the end of the harvest cycle.

• Fill Cycle–15 sec. after activation.

Shutdown Delay:

1. Bin Full

If FS is open, Comp stops and cycle returns to 1-min. ll.

the 5-min. short cycle protection timer terminates.

• Harvest Cycle–At the end of the harvest cycle, or up to 15 sec. into the

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

Otherwise, at the end of the next harvest cycle.

components de-energized.

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

MBC open (MBC actuator paddle engaged)

Green "BC CLOSED" LED off

Yellow "BC OPEN" LED on

The "WASH" position on the control switch is used when cleaning and sanitizing the icemaker. 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 icemaker will not restart when the control switch is

placed in the "ICE" position.

Cycle

Steps

Startup

16

Shutdown

and Restart

Legend:

Comp–compressor

FM–fan motor

FMR–fan motor-remote

FS–oat switch

HGV–hot gas valve

LLV–liquid line valve

MBC–mechanical bin control

PM–pump motor

MBC Operation

WV–inlet water valve

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.C. Control
Board Check." Check dip switch settings to assure that S4 dip switch 3, 4, 7, 8, 9, 10 and
S5 dip switch 1 through 5 ("G" CB) are in the factory default position. S4 dip switch 1, 2,

5, 6 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.

• On 3-phase models, the neutral (W) is provided through MT. 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 MT. If 208-230VAC is present, check MT 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.

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

17

1. "E" and "G" Control Board without Harvest Pump Timer Diagnosis

3) Power On: Turn on the power supply, then move the control switch to the "ICE" position.
A 5-sec. delay occurs.

• "E" Control Board: CB red "POWER OK" LED turns on.

• "G" Control Board: CB red "POWER OK" LED and green "BC CLOSED" LEDturn on.

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

interrupted (K2 connector).

• Check CB using the steps in "II.C. Control Board Check."

• "G" CB: If yellow "BC OPEN" LED is on (indicating a full bin), check MBC.

See"II.D.2. Mechanical Bin Control Check and Cleaning."

a) Power On Diagnosis: If CB red "POWER OK" LED is off, conrm closed TBC and

10A fuse is good. If TBC is open, remove ice from bulb and warm bulb in hand. If
TBC does not close, replace TBC. See "II.D.1. Thermostatic Bin Control Check."
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, HM, LLV, strainer, check valve, drier, and damaged
line set or tting. Also conrm WRV opens in freeze cycle.

Conrm that the location meets installation requirements:

• The icemaker 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.

18

4) 1-Minute Fill Cycle – LED 4 is on. WV energizes. After 1 min., CB checks for a closed

FS. If FS is closed, harvest cycle begins. If harvest cycle begins (Comp, HGV, and FMR
energize), continue to step 5. If FS is open, WV remains energized through additional
1-min. ll cycles until water enters the water tank and 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.E. Float Switch Check and Cleaning." If FS is
closed and CB fails to start the harvest cycle after 1 min., replace CB.

5) 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).
The harvest timer has settings of 60, 90, 120, and 180sec. Thepump-out timer (S4dip
switch 3 & 4) acts in place of the harvest timer during cycles with a pump-out (S4 dip
switch 5 & 6). WV remains energized during harvest for a maximum of 6min. or the
length of harvest, whichever is shorter.

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.

19

e) 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). Check discharge line temperature. For a
thermistor check, see "II.F.Thermistor Check." If 1-min. ll cycle starts after harvest
timer terminates, check that FS is clean and operating properly, see "II.E. 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 2 min.

Maximum harvest time allowed is 20 min.

NOTICE! On models with "G" control board and no harvest pump timer relays,
S4dip switch 7 must remain off. Otherwise, PM energizes in reverse direction the
last 50 seconds of harvest and empties water from water tank.

6) Freeze Cycle – LED 1 is on. Comp and FMR continue. PM, FM, and LLVenergize.
WV and HGV de-energize. Appliance is held in freeze by a 5-min. short cycle protection
timer. After 5-min. timer terminates and FSopens, freeze cycle terminates.

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

PM, FM, and LLV energize. Conrm WRV opens. Next, conrm WV and HGV
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 Sheet" and
"VIII.B.Performance Data."

b) Comp and FMR Diagnosis: If Comp 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 "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 ok,
check Comp external overload, 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.B. Performance Data." 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, replace CB. If 115VAC is not
present, replace WV (bypassing). If HGV did not de-energize, check for 115VAC at
CB K1 #2 (P) to neutral (W). If 115VAC is present after PM energizes, replace CB.
If115VAC is not present, replace HGV (bypassing).

20

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 (R) to neutral (W). If 115VAC is present at CB
K1 #4 (R) and not at control switch #5 (R), check control switch continuity between
#5 (R) and #4 (R). Replace as needed. If 115VAC is present at control switch #5 (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.

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

check refrigerant pressures. See "VIII.B. Performance Data."
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.B.
Performance Data." 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.E. 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.B. Performance Data."

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.E. Float Switch Check and Cleaning" for erratic operating FS.

21

7) Pump-Out Cycle – LEDs 1, 3, and 2 are on (10/20 second pump-out). Timing of the
rst pump-out is dependent on CB. "E" CB rst pump-out is after the rst freeze cycle.
"G" CB rst pump-out is determined by S4 dip switch 5 & 6. See the table below.

"E" & "G" Control Board Settings 1st Pump-Out

S4 Dip Switch Setting

No. 5 No. 6

OFF OFF Every cycle After 1st freeze cycle After 2nd freeze cycle

ON OFF Every 2 cycles After 3rd freeze cycle

OFF ON Every 5 cycles After 6th freeze cycle

ON ON Every 10 cycles After 11th freeze cycle

Pump-Out

Frequency

"E" Control Board "G" Control Board

Comp and FMR continue, HGV energizes. If S4dip switch 3 & 4 are set to 3 off and 4
on, LED 4 turns on and WV energizes. FM and LLVde-energize. PM stops for 2 sec.,
then reverses for 10/20 sec. depending on pump-out timer (S4 dip switch 3 & 4) setting.
When the pump-out timer terminates, pump-out is complete. The pump-out frequency
control (S4 dip switch 5 & 6) is factory set, and generally no adjustment is required.
However, the pump-out frequency control can be set to have a pump-out occur every
cycle, or every 2, 5, or 10 cycles. For details, see "III.C.4. Pump-Out Frequency Control
(S4 dip switch 5 & 6)."

Pump-Out Diagnosis: In the freeze cycle before pump-out (see table above),
disconnect CB black K5 connector (FS connector) after 5 min. of freeze. Check that PM

stops and re-starts and water is owing down the drain through CV. If PM does not stop

and re-start, check that CB LEDs 1, 3, and 2 are on. If not, replace CB. IfLEDs1,3,
and 2 are on and PM does not energize, check for 115VAC at
CB K1 #5 (DBU) to neutral (W). If 115VAC is not present, replace CB.
If 115VAC is present, make sure the drain line is not clogged and that CV is clean and
operating properly.

Conrm FM and LLV de-energize. If FM or LLV is energized with LEDs 1, 3, and 2 on,
replace CB.

8) Normal Harvest Cycle – Same as the initial harvest cycle. Return to step 5 above.
Note: Appliance continues to cycle until TBC or MBC is satised or power is turned off.

The appliance always restarts at the 1-min. ll cycle.

22

9) Shutdown

a) "E" Control Board: Thermostatic Bin Control (TBC):

When the appliance is running, hold ice in contact with the thermostatic
bulb. TBC switch opens within 10 sec., shutting down the appliance. TBC is
factory set, and generally no adjustment is required. However, adjustment
may be needed in some conditions, particularly at higher altitude locations.

NOTICE! Do not adjust S4 dip switch 7 out of the factory default position.
This dip switch must be left in the factory default position or the
appliance will not operate correctly. Diagnosis: See "II.D.1. Thermostatic Bin

Control Check and Cleaning."

b) Mechanical Bin Control:

See "II.D.2. Mechanical Bin Control Check and Cleaning."

Legend: CB–control board; Comp–compressor; CV–check valve; FM–fan motor;

FMR–fan motor-remote; FS–oat switch; HGV–hot gas valve; HM–headmaster
(C.P.R.); HPS–high-pressure switch; LLV–liquid line valve; MBC–mechanical
bin control; PM–pump motor; TBC–thermostatic bin control; TXV–thermostatic
expansion valve; WRV–water regulating valve; WV–inlet water valve

23

2. "G" Control Board with Harvest Pump Timer 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 green "BC CLOSED" LED turn
on. If yellow "BC OPEN" LED is on (indicating a full bin), check MBC. Move ice away
from MBC actuator paddle. If yellow "BC OPEN" LED stays on, see"II.D.2. Mechanical
Bin Control (MBC) Check."

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.C. Control Board Check."

• Conrm CB green "BC CLOSED" LED is on. If CB yellow "BC OPEN" LED is on,

remove ice from BC. If no ice is around BC and yellow "BC OPEN" LED is on,
see "II.D.2. Mechanical Bin Control (MBC) Check."

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.

24

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, FMR energized), continue to step 5a. If FS is open, WV remains energized
through additional 1-min. ll cycles until water enters the water tank and 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.E. 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,

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). The harvest timer has settings of 60, 90, 120, and 180 sec. The
pump-out timer (S4 dip switch 3 & 4) acts in place of the harvest timer during cycles
with a pump-out (S4 dip switch 5 & 6). WV and X11 relay are energized during harvest
for a maximum of 6 min. or the length of harvest minus 50sec., whichever is shorter.
50sec. before harvest terminates, PM energizes. 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. If Comp is energized and evaporator is not warming, check that HGV
energizes and opens. Check for 115VAC at CB K1 #2 (P) to a neutral(W). If 115VAC
is not present and LED 2 is on, replace CB. If115VAC is present, check coil voltage
and continuity. Replace as needed. Conrm that LLV is de-energized and closed (not
bypassing). If energized, replace CB. Ifde-energized and bypassing, replace LLV.
Conrm WRV is not leaking by. If evaporator is warming, PM energizes for the last 50
sec. of harvest.

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.

25

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). 50 sec. before the harvest timer terminates, LED
3turns on and PM energizes. Comp, FMR, HGV, and X10 relay continue. LED 4 turns
off, WV and X11 relay de-energize.
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.F. Thermistor
Check." If the thermistor reading is in proper range, dip switch 7 is on, and PM does
not energize 50 sec. 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(R). Ifcontacts are open, replace control
switch. If contacts are closed and 115VAC is present between control switch terminal #5
(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). Check discharge line temperature. For a thermistor
check, see "II.F.Thermistor Check." If 1-min. ll cycle starts after harvest timer
terminates, check that FS is clean and operating properly, see "II.E. 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 2 min.

Maximum harvest time allowed is 20 min.

NOTICE! S4 dip switch 7 must remain on. Otherwise, PM will not energize during
the last 50 sec. of harvest.

26

6) Freeze Cycle – LED 1 is on. Comp, 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. 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.

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 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 Sheet" and
"VIII.B.Performance Data."

b) Comp and FMR Diagnosis: If Comp 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 "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.B. Performance Data." 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 (R) to neutral (W). If 115VAC is present at CB
K1 #4 (R) and not at control switch #5 (R), check control switch continuity between
#5 (R) and #4 (R). Replace as needed. If 115VAC is present at control switch #5 (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.

27

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

check refrigerant pressures. See "VIII.B. Performance Data."
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.B.
Performance Data." 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.E. 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.B. Performance Data."

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.E. 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& 6. See the table below.

"G" Control Board Settings

S4 Dip Switch Setting

No. 5 No. 6

OFF OFF Every cycle After 2nd freeze cycle

ON OFF Every 2 cycles After 3rd freeze cycle

OFF ON Every 5 cycles After 6th freeze cycle

ON ON Every 10 cycles After 11th freeze cycle

Pump-Out

Frequency

"G" Control Board

Comp and FMR continue, HGV energizes. 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. FM and LLV

de-energize. PM stops for 2 sec., then reverses for 10/20 sec. depending on pump-out
timer (S4dip switch 3 & 4) setting. When the pump-out timer terminates, pump-out

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is complete. The pump-out frequency control (S4 dip switch 5 & 6) is factory set, and
generally no adjustment is required. However, the pump-out frequency control can be
set to have a pump-out occur every cycle, or every 2, 5, or 10 cycles. For details, see
"III.C.4. Pump-Out Frequency Control (S4 dip switch 5 & 6)."

Pump-Out Diagnosis: In the freeze cycle before pump-out (see table above), after
5min. of freeze disconnect CB black K5 connector (FS connector). Check that PM

stops and re-starts and that PM rotation is correct (water owing down the drain through

CV). If PM does not stop and re-start, check that CB LEDs 1, 3, and 2 are on. If not,
replace CB. IfLEDs1,3, and 2 are on and PM does not energize, check for 115VAC
at CB K1 #5 (DBU) to neutral (W). If 115VAC is not present, replace CB. If 115VAC
is present, check that X10 relay is de-energized. If not, check X11 relay status. If X11
relay is energized, replace CB. If X11 relay is de-energized and X10 relay is energized,
replace X11 relay (contacts sticking). If X10 relay is de-energized, check for 115VAC
at terminal #6 (DBU) to neutral (W) and terminal #2 (DBU) to neutral (W). If 115VAC is
present on terminal #6 (DBU) and not on terminal #2 (DBU), replace X10 relay. If PM is
energized and rotating in pump-out rotation, make sure the drain line is not clogged and
that CV is clean and operating properly.

Conrm FM and LLV de-energize. If FM or LLV are energized with LEDs 1, 3, and 2 on,
replace CB.

8) Normal Harvest Cycle – Same as the initial harvest cycle. Return to step 5a) above.

Note: Appliance continues to cycle until MBC is satised or power is switched off. The

appliance always restarts at the 1-min. ll cycle.

9) Shutdown

Mechanical Bin Control:

See "II.D.2. Mechanical Bin Control Check."

Legend: CB–control board; Comp–compressor; CV–check valve; FM–fan motor;

FMR–fan motor remote; FS–oat switch; HGV–hot gas valve; HM–headmaster
(C.P.R.); HPS–high-pressure switch; LLV–liquid line valve; MBC–mechanical
bin control; PM–pump motor; TXV–thermostatic expansion valve; WRV–water
regulating Valve; WV–inlet water valve

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