Hoshizaki F450MAJC User Manual

Service Manual

Modular Flaker with
F-A and F-C Control Boards

Models
H and J Series

hoshizakiamerica.com

Number: 73204
Issued: 7-23-2014
Revised: 9-21-2016

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 and may result in costly water
damage. 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 ................................................................................................. 6

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

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

1. Air-Cooled Models .................................................................................................... 8

2. Water-Cooled Models ............................................................................................. 9

3. Remote Air-Cooled Models .................................................................................... 10

4. Low-Side, Parallel Rack System Models ................................................................11

B. Icemaking Unit ............................................................................................................ 12

C. Water/Refrigeration Circuit Diagram ............................................................................ 13

1. Air-Cooled Models .................................................................................................. 13

2. Water-Cooled Models ............................................................................................ 14

3. Remote Air-Cooled Models .................................................................................... 15

4. Low-Side, Parallel Rack System Models ............................................................... 16

II. Sequence of Operation and Service Diagnosis ............................................................... 17

A. Sequence of Operation Flow Chart ............................................................................. 17

1. Icemaking and Drain Cycle .................................................................................... 17

2. Shutdown .............................................................................................................. 18

B. Service Diagnosis ....................................................................................................... 19

C. Control Board Check ................................................................................................... 25

D. Bin Control Check ....................................................................................................... 30

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

F. Diagnostic Tables ......................................................................................................... 36

III. Controls and Adjustments ............................................................................................... 39

A. Control Board .............................................................................................................. 39

1. Control Board Layout ............................................................................................. 40

2. LED Lights and Audible Alarm Safeties ................................................................. 41

3. Ice Purge Cycle Bypass ......................................................................................... 42

B. Controls and Adjustments ........................................................................................... 42

1. Default Dip Switch Settings .................................................................................... 42

2. BC1 (Infrared Sensor) Shutdown Delay (S1 dip switch 1, 2, 3) ............................. 43

3. Drain Frequency Control (S1 dip switch 4) ............................................................ 43

4. Continuous Dispensing Timer (S1 dip switch 5 & 6) .............................................. 43

5. Bin Control Selector (S1 dip switch 7) ................................................................... 44

6. BC(2) (Mech. Stand-Alone or Backup (only)) Shutdown Delay (S1 dip switch 8) .. 44

7. Factory Use (S1 Dip Switch 9 & 10) ....................................................................... 44

C. Power Switch and Control Switch ................................................................................ 45

IV. Refrigeration Circuit and Component Service Information.............................................. 46

A. Refrigeration Circuit Service Information .................................................................... 46

B. Component Service Information .................................................................................. 49

3

V. Maintenance .................................................................................................................... 56

VI. Disposal .......................................................................................................................... 58

VII. Technical Information ..................................................................................................... 59

A. Specication & Performance Data Sheets .................................................................. 59

1a. F-1001MAH .......................................................................................................... 59

1b. F-1001MAH-C ...................................................................................................... 60

2a. F-1001MWH ......................................................................................................... 61

2b. F-1001MWH-C ..................................................................................................... 62

3a. F-1001MRH .......................................................................................................... 63

3b. F-1001MRH-C ...................................................................................................... 64

4a. F-1501MAH .......................................................................................................... 65

4b. F-1501MAH-C ..................................................................................................... 66

5a. F-1501MWH ......................................................................................................... 67

5b. F-1501MWH-C ..................................................................................................... 68

6a. F-1501MRH.......................................................................................................... 69

6b. F-1501MRH-C ...................................................................................................... 70

7. F-2001MWH ........................................................................................................... 71

8a. F-2001MRH ......................................................................................................... 72

8b. F-2001MRH-C ...................................................................................................... 73

8c. F-2001MRH3 .........................................................................................................74

9. F-2001MLH ............................................................................................................ 75

10. FD-650MAH-C ..................................................................................................... 76

11. FD-650MWH-C ..................................................................................................... 77

12. FD-650MRH-C ..................................................................................................... 78

13. FD-1001MAH-C ................................................................................................... 79

14. FD-1001MRH-C ................................................................................................... 80

15a. F-450MAJ .......................................................................................................... 81

15b. F-450MAJ-C ....................................................................................................... 82

16a. F-801MAJ........................................................................................................... 83

16b. F-801MAJ-C ....................................................................................................... 84

17a. F-801MWJ.......................................................................................................... 85

17b. F-801MWJ-C ...................................................................................................... 86

18a. F-1001MAJ ......................................................................................................... 87

18b. F-1001MAJ-C ..................................................................................................... 88

19a. F-1001MWJ ........................................................................................................ 89

19b. F-1001MWJ-C .................................................................................................... 90

20a. F-1001MRJ ........................................................................................................ 91

20b. F-1001MRJ-C ..................................................................................................... 92

21a. F-1001MLJ ......................................................................................................... 93

21b. F-1002MLJ ......................................................................................................... 94

22a. F-1002MAJ ........................................................................................................ 95

22b. F-1002MAJ-C ..................................................................................................... 96

23a. F-1002MWJ ....................................................................................................... 97

23b. F-1002MWJ-C .................................................................................................... 98

24a. F-1002MRJ ........................................................................................................ 99

24b. F-1002MRJ-C .................................................................................................. 100

4

25a. F-1501MAJ........................................................................................................101

25b. F-1501MAJ-C ................................................................................................... 102

26a. F-1501MWJ...................................................................................................... 103

26b. F-1501MWJ-C .................................................................................................. 104

27a. F-1501MRJ ...................................................................................................... 105

27b. F-1501MRJ-C ................................................................................................... 106

28. FD-1001MAJ-C .................................................................................................. 107

29. FD-1001MRJ-C .................................................................................................. 108

30. FD-1002MAJ-C .................................................................................................. 109

31. FD-1002MRJ-C ...................................................................................................110

B. Wiring Diagrams ......................................................................................................... 111

1. F-1001MAH(-C), F-1001MWH(-C), F-1001MRH(-C), FD-1001M_H-C ................... 111

2. F-1501M_H(-C) ..................................................................................................... 112

3. F-2001MWH(-C), F-2001MRH(-C)(3),F-2001MWJ(-C), F-2001MRJ(-C)(3) ..........11 3

4. F-2001MLH, F-1001MLJ, F-1002MLJ, F-2001MLJ ................................................ 114

5. FD-650M_H-C ......................................................................................................11 5

6. F-450MAJ(-C) ....................................................................................................... 116

7. F-801M_J(-C) ........................................................................................................117

8. F-1001MAJ(-C), F-1001MWJ(-C), F-1001MRJ(-C) ................................................ 118

9. F-1002MAJ(-C), F-1002MWJ(-C), F-1002MRJ(-C), FD-1002M_J-C ..................... 119

10. F-1501M_J(-C) ................................................................................................... 120

11. FD-1001M_J-C ................................................................................................... 121

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 installation, 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 install, operate, 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 the 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 damage.

• 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 fuse, 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.

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

• Move the power 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.

• Do not place ngers or any other objects into the ice discharge opening.

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

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 the 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.

• Wire routing (conduit) and disconnect (if required) 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 damage.

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 provided in the instruction manual.

• 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

Inlet Water Valve

Float Switch

Reservoir

Spout

Evaporator
Heater (-C)

Drip Pan

Ice Chute

Water Supply Inlet

Bin Control 2
(Mechanical)
(If Applicable)

Junction Box

High-Pressure Switch

Thermostatic
Expansion Valve

Evaporator

Drain Valve

Gear Motor

Bin Control 1
(Infrared Sensor)

Model Shown: F-1501MAH

Control Switch

Power Switch

Fan Motor

Condenser

Drier

Compressor

8

2. Water-Cooled Models

Spout

Drip Pan

Evaporator

Thermostatic
Expansion Valve

Drain Valve

Float Switch

Reservoir

Inlet Water Valve

Water Supply Inlet

Junction Box

Control Switch

Power Switch

Water Regulating

Valve
Water-Cooled
Condenser

High-Pressure Switch

Gear Motor

Ice Chute

Drier

Compressor

Bin Control 1
(Infrared Sensor)

Model Shown: FD-650MWH-C

9

3. Remote Air-Cooled Models

Float Switch

Reservoir

Spout

Drip Pan

Evaporator
Heater (-C)

Inlet Water Valve

Bin Control 2
(Mechanical)
(If Applicable)

Water Supply Inlet

High-Pressure Switch

Junction Box

Evaporator

Thermostatic
Expansion Valve

Drain Valve

Inlet Water Valve

Reservoir

Spout

Water Supply Inlet

Float Switch

Gear Motor

Junction Box

Ice Chute

Model Shown: F-1001MRH-C

High-Pressure Switch

Compressor

Crankcase
Heater

Control Switch

Power Switch

Reciever

Drier

Evaporator
Heater (-C)

Control Switch

Power Switch

Drip Pan

Reciever

Evaporator

Bin Control
(Infrared Sensor)

Drain Valve

Model Shown: F-1001MRJ-C

10

Gear Motor

Ice Chute

Drier

Compressor

Thermostatic
Expansion Valve

Crankcase
Heater

4. Low-Side, Parallel Rack System Models

Inlet Water Valve

Float Switch

Reservoir

Spout

Evaporator
Heater (-C)

Evaporator

Bin Control 2
(Mechanical)
(If Applicable)

Water Supply Inlet

Control Switch

Thermostatic
Expansion Valve

Drain Valve

Gear Motor

Ice Chute

Bin Control 1
(infrared sensor)

Model Shown: F-2001MLH

Power Switch

Liquid Line Valve

Suction Line Valve

Evaporator Pressure
Regulator Valve (EPR)

11

B. Icemaking Unit

Cutter

Extruding Head-Upper Bearing

Evaporator Heater (-C Models)

Drip Pan

Auger

Cylinder

Mechanical-Seal

O-Ring

Lower Housing

Seal Bolt

Insulation

Socket Head Cap Screw
with Split Lock Washer

Hex Bolt and Washer

Spline Coupling

Gear Motor

Model Shown: F-1501MAH

12

C. Water/Refrigeration Circuit Diagram

1. Air-Cooled Models

Inlet Water Valve

Float

Water Supply
Line

Reservoir

Overow

Switch

Water Level

Evaporator

Spout

Evaporator Condensate
Drain Pan (Drip Pan)

Insulation

Drain Outlet

Drier

Condenser
Fan Motor

Drain
Valve

Gear Motor Drain Pan

Thermostatic
Expansion Valve

Gear Motor

Drain Hose

Condenser

High Pressure
Switch

Compressor

13

2. Water-Cooled Models

Water Supply
Line

Reservoir

Inlet Water Valve

Float
Switch

Overow

Water Level

Evaporator

Spout

Evaporator Condensate
Drain Pan (Drip Pan)

Drain
Valve

Thermostatic
Expansion Valve

Gear Motor

Drain Hose

Insulation

Drain Outlet

Water Supply Line

Condenser

Drain Outlet

Water Regulating Valve

Gear Motor Drain Pan

Drier

High-Pressure
Switch

Compressor

14

3. Remote Air-Cooled Models

Inlet Water Valve

Float

Water Supply
Line

Reservoir

Overow

Switch

Water Level

Evaporator

Spout

Evaporator Condensate
Drain Pan (Drip Pan)

Insulation

Drain Outlet

Drier

Condenser Fan Motor

Drain
Valve

Gear Motor Drain Pan

Thermostatic
Expansion Valve

Gear Motor

Drain Hose

Remote Condenser

High-Pressure
Switch

Compressor

15

4. Low-Side, Parallel Rack System Models

Inlet Water Valve

Water Supply
Line

Reservoir

Overow

Float
Switch

Water Level

Evaporator

Spout

Evaporator Condensate
Drain Pan (Drip Pan)

Insulation

Drain
Valve

Drain Outlet

NOTICE! F-1001MLH Use only with R-404A
F-1002MLJ Use only with R-404A, R-407A, or R-407F

EPR Settings:
F-1001MLH: R-404A EPR Setting: 31 PSIG
F-1002MLJ: R-404A EPR Setting: 31 PSIG
R-407A EPR Setting: 22 PSIG
R-407F EPR Setting: 23 PSIG

From Rack System

Evaporator Pressure Regulator (EPR Valve)

Thermostatic
Expansion Valve

Gear Motor

Drain Hose

Gear Motor Drain Pan

Liquid Line Valve

To Rack System

Suction Line Valve

16

II. Sequence of Operation and Service Diagnosis

A. Sequence of Operation Flow Chart

1. Icemaking and Drain Cycle

WV continues

GM de-energized

FM de-energized

FMR de-energized

Low Water Safety

Shutdown

90. sec. PT terminates

unit shuts down and

1-beep alarm continues.

When UFS closes, alarm

resets and 2. Ice Purge

Cycle starts.

UFS open

WV energized

Comp de-energized

LLV de-energized

SLV de-energized

GM continues

FM continues

FMR continues

90 sec.

Low Water Safety

Purge Timer

90 sec. FT exceeded,

90 sec. PT starts and

1-beep alarm sounds

LFS closed

UFS closed

FZT starts (30

min.)

FT terminated

WV de-energized

Comp continues

GM continues

FM continues

FMR continues

LLV continues

SLV continues

Normal Operation

to "1. Fill Cycle" above

4. Icemaker Restart

10-min. DT terminated

DV de-energized

1-in-12 DT reset

Control Board Sequence of Operation Flow Chart - Icemaking and Drain Cycle

4. 1-in-12 Drain Cycle - Although the factory default 1-in-1 drain cycle

is recommended, a 1-in-12 drain cycle is available. For 1-in-12 drain

3. Freeze Cycle

cycle sequence, see "3. 1-in-12 Hour Drain Cycle & Restart (optional)."

2. Ice Purge Cycle

1. Fill Cycle

Rell

1-in-1 drain cycle. DV opens for 2 sec. every hour

(CB S1 Dip Switch 4).

To bypass, press the

"SERVICE" button after

FT Maximum

90 sec.

Icemaker status does not change.

5 min.

GM starts.

5 or 30 sec.

FT off (90 sec.)

30-min. FZT

FZT exceeded (LFS does not

open): CB shuts down icemaker

(S1 Dip Switch 7)

UFS open

LFS open (WV on)

and sounds a 5-beep alarm.

Comp energized

EH energized

GM energized

FT starts (90 sec.)

FZT terminated

WV energized

LLV energized

SLV energized

GM continues

FM energized

FMR energized

Comp continues

FM continues

GM continues

FMR continues

FM continues

FMR continues

LLV continues

SLV continues

DV de-energizes, no

2. Continued Operation

interruption in ice production

3. 10-Min. Drain

2. Ice Purge Cycle

DV energized

GM de-energized

FM de-energized

FMR de-energized

5 min.

Comp de-energized

LLV de-energized

SLV de-energized

GM continues

FM continues

FMR continues

DV energizes for 2 sec.

operation

1. DT Initiates DC

FT-ll timer (low water safety)

FZT-freeze timer

GM-gear motor

LFS-lower oat switch

LLV-liquid line valve (MLH)

PT-purge timer

SLV-suction line valve (MLH)

UFS-upper oat switch

WV-inlet water valve

FT Maximum

90 sec.

LFS closed

UFS closed

1. DT Initiates DC

Continued uninterrupted

FZT starts

FT terminated

WV de-energized

Power Switch "ON"

Control Switch in "ICE"

1. Startup

POWER OK LED on

BC1 Green LED on

Startup

BC1 Yellow LED off

BC(2) Closed

WV energized

If Fill > 90 sec. FT

1-beep alarm sounds

WV continues

When UFS closes

alarm resets and

2. Ice Purge Cycle starts.

17

(CB S1 dip switch 4 "OFF")

2. 1-in-1 Drain Cycle

& Restart (optional)

(CB S1 dip switch 4 "ON")

3. 1-in-12 Drain Cycle

Legend:

BC-bin control (mechanical stand-alone)

BC1-bin control 1 (infrared sensor)

BC2-bin control 2 (mechanical backup)

CB-control board

Comp-compressor

DC-drain cycle

DT-drain timer

DV-drain valve

EH-evaporator heater

FM-fan motor

FMR-fan motor-remote

2. Shutdown

Note for models with BC1 and BC2:

4. Icemaker Restart

If BC1 fails to shutdown the icemaker, BC2

opens and a 9-beep alarm sounds. See

"II.D. Bin Control Check."

to "2. Ice Purge Cycle"

in Icemaking and Drain

BC1 Green LED on

BC1 Yellow LED off

Cycle Chart

BC1 de-activated

Control Board Sequence of Operation Flow Chart - Shutdown

3. Icemaker Off

2. Ice Purge Cycle

1. Bin Full

BC1 delay determined by CB S1 dip

switch 1, 2, 3

5 min.

BC1 Yellow LED (ashing or steady)

BC1 Green LED on

BC1 Yellow LED off

GM de-energized

BC1 activated

FM de-energized

Comp de-energized

FMR de-energized

LLV de-energized

SLV de-energized

GM continues

FM continues

FMR continues

to "2. Ice Purge Cycle" in Icemaking

Ice level lowered

2. Icemaker Off 3. Icemaker Restart

6 to 10 sec.

1. Bin Full

BC

and Drain Cycle Chart

BC(2) closed

All Components

Immediate

BC(2) open

BC2

Legend:

BC-bin control (mechanical stand-alone)

BC1-bin control 1 (infrared sensor)

(BC paddle and proximity

switch disengaged)

de-energized

BC paddle and

proximity switch

engaged

Note for models with BC1 and BC2:

When BC2 is activated, a 9-beep alarm

BC2-bin control 2 (mechanical backup)

sounds. See "II.D. Bin Control Check."

CB-control board

Comp-compressor

FM-fan motor

FMR-fan motor-remote

GM-gear motor

LLV-liquid line valve (MLH)

SLV-suction line valve (MLH)

1. BC1 Shutdown (infrared sensor)

2. BC(2) Shutdown (mechanical)

18

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. Use extreme caution and exercise safe electrical practices.

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

• 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 icemaker and dispenser unit/ice storage bin are
clean after service.

1. Ice Production Check

To check production, prepare a bucket or pan to catch the ice and a set of scales to
weigh the ice. After the appliance has operated for 10 to 20 min., catch the ice production
for 10 min.. Weigh the ice to establish the batch weight. Multiply the batch weight by
144 for the total production in 24 hours. When conrming production or diagnosing
low production, reference production information found in "VII.A. Specication and
Performance Data."

19

2. Diagnostic Procedure

This 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 appliance nameplate, and adequate water pressure (10 PSIG to 113 PSIG).

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

establish a good neutral connection.

• When checking low voltage (24VAC), always choose a neutral (LBU) wire to
establish a good neutral connection.

• When checking control board DC voltage (5VDC), always place the red positive
test lead from the multimeter to CB K5 pin closest to CB K4 connector.
See "II.C. Control Board Check."

• When checking BC1 (infrared sensor) (20VDC), check that the infrared sensor
green LED is on. This green LED conrms 20VDC power from CB K6to the
infrared sensor and remains on constantly. If green LED is not on, check for
20VDC from CB K6 #1 (DBU) to CB K6 #3 (BR). See "II.D. Bin Control Check."

• To speed up the diagnostic process, the 5-min. ice purge cycle may be bypassed
by pressing the "SERVICE" button on the control board after the gear motor
starts. WARNING! Risk of electric shock. Care should be taken not to touch
live terminals.

• If the icemaker is in alarm, see "III.A.2. LED Lights and Audible Alarm Safeties."

• FM/FMR and EH (-C model except FD-650) energize when "GM" LED turns on.

• MLH Model: CB X1 relay energizes LLV and SLV.

• CB monitors the following switches with 5VDC during the icemaking process:
Control Switch (CS), High-Pressure Switch (HPS), Float Switch (FS),
Compressor Control Relay/Gear Motor Protect Relay (CCR/GMPR), and Bin
Control (2) (mechanical stand-alone or backup). When 5VDC is present across
any of these switches, the switch is open.

1) Remove the front panel, then move the power switch to the "OFF" position. Move the
control switch to the "DRAIN" position, then move the power switch back to the "ON"
position. Replace the front panel in its correct position.

2) Allow the water system to drain for 5 min.

3) Remove the front panel. Move the power switch to the "OFF" position, then turn off the
power supply.

4) Remove the control box cover and access CB.

5) Check the CB S1 dip switch settings, see "III.B.1. Default Dip Switch Settings" to assure
that they are in the correct positions. For proper operation of BC1 (infrared sensor),
conrm that S1 dip switch 7 is in the "ON" position.

20

6) Startup–CB "POWER OK" LED is on. Turn on the power supply, then move the power
switch to the "ON" position. Make sure the control switch is in the "ICE" position.
CB "POWER OK" LED and IS (BC1 if applicable) green LED turn on.
Diagnosis CB "POWER OK" LED: Check that CB "POWER OK" LED is on. Ifnot,
check for 115VAC at control transformer brown (BK on 115VAC models (except
FD-650M_H-C) and BR on 208/230VAC models and 115VAC FD-650M_H-C) wire to
neutral (W). If 115VAC is not present, check the power switch and breaker. If 115VAC
is present, check control transformer continuity. Replace as needed. Next, check for
24VAC at control transformer red (R) wire to neutral (LBU). If 24VAC is not present,
check control transformer continuity. Replace as needed. If24VAC is present, check
24VAC 1A fuse. If fuse is good, check for 24VAC at CB K8 #1 (W/R) to CB K8 #2 (LBU).
If 24VAC is present and "POWER OK" LED is off, replace CB.
Diagnosis BC(2) (mechanical stand-alone or backup): Check that the actuator
paddle is properly positioned. Check continuity across BC(2). If open, replace BC(2).
Next, check VDC at CB K8#3(GY) to CB K8 #4 (GY). When BC(2)is closed 0VDC is
read. Move the actuator paddle to open BC(2). When open, 5VDCis present between
CB K8 #3 (GY) and CB K8#4(GY). If 5VDC is not present when BC(2) is open, replace
CB. Return actuator to its normal position.
Diagnosis BC1 (infrared sensor): If "POWER OK" LED is on and BC1 green LED
is off, check 20VDC at CB K6 #1 (DBU) to CB K6 #3 (BR). If 20VDC is not present,
conrm dip switch 7 is in the "ON" position. If dip switch 7 is in the "ON" position and
20VDC is not present, replace CB. If BC1 yellow LED is on or ashing, move ice away
from lens. If no ice is present, clean the lens with a warm, clean damp cloth. If cleaning
the lens does not work, replace BC1.

7) Fill Cycle – "WTRIN" LED is on. Reservoir is empty and LFS and UFS are open.
90-sec. FT starts. WV energizes and ll cycle starts. LFS closes. Nothing occurs at this
time. Reservoir continues to ll until UFS closes. When UFS closes, WV de-energizes,
90-sec. FT is terminated, and CB "WTRIN" LED turns off. 30-min. FZTand 30-sec.
GM delay timer start. IfUFS remains open longer than 90 sec. after LFS opens,
FTexceeded and CB sounds a 1-beep alarm. WVremains energized until UFS closes.
Alarm resets automatically when UFS closes. Diagnosis: If reservoir is empty and
"WTRIN" LED is off, conrm LFS status. See "II.E.1. Float Switch Check." IfLFS is open
and "WTRIN" LED is off, replace CB. If "WTRIN" LED is on, check that the reservoir lls.
If not, check water supply line shut-off valve, water lters, and WVscreen. If "WTRIN"
LED is on and WV is off, check CB K2 #8(O) to a neutral (LBU) for 24VAC. If24VAC is
not present, check CB K2 #9(W/R) to a neutral (LBU) for 24VAC. If 24VAC is present
on CB K2 #9(W/R)and not on CB K2 #8 (O), replace CB. If 24VAC is present on
CB K2 #8(O), check continuity through WV solenoid. If open, replace WV. If WV is
energized and rell exceeds FT with no water in the reservoir, check for DV leaking.
Ifreservoir is full and overowing check for open UFS. See "II.E.1. Float Switch Check."
If UFS is closed, check that WV de-energizes. If not, check CB K2 #8 (O) to a neutral
(LBU) for 24VAC. If 24VAC is present, replace CB. IfWV de-energizes and water
continues to ll the reservoir, replace WV.

21

8) Ice Purge Cycle – "GM" LED is on. 30-sec. GM delay timer terminates. GM,
CCR/GMPR, FM/FMR, and EH (-C model except FD-650) energize. Once CCR/GMPR
energizes, 5VDC circuit closes through CCR/GMPR terminal #3 (W/O) and terminal
#5 (W/O) and CB K9 #5 (W/O) and K9 #6 (W/O). After 5VDC circuit closes, 5-min.
ice purge timer starts. Tobypass the 5-min. Ice Purge Cycle, press the "SERVICE"
button on CB after the "GM" LED turns on. WARNING! Risk of electric shock. Care
should be taken not to touch live terminals. Diagnosis: If "GM" LED is off, check
that UFS closes and WV de-energizes. IfUFS is closed, 30 sec. has passed, and "GM"
LED remains off, replace CB. If"GM" LED is on and GM is off, check CB K1 #2 (BK
or BR) to a neutral (W) for 115VAC. If115VAC is not present, check 115VAC power
supply. If115VAC is present, check CB K1 #3(BK, P, or R) to a neutral (W). If 115VAC
is present on CB K1 #2 (BK or BR) and not on CB K1 #3 (BK, P, or R), replace CB.
If115VAC is present on CB K1#3 (BK, P, or R), check GM fuse, GM internal protector,
GM windings and capacitor, and GM coupling between auger and GM. When GM
energizes,
CCR/GMPR energizes starting 5-min. ice purge timer. If FM/FMR does not start, check
FM/FMR capacitor, FM/FMR windings, and FM/FMR bearings.

9) Freeze Cycle – "COMP" and "GM" LEDs are on. The 5-min. ice purge timer
terminates. GM, EH, CCR, and FM/FMR continue. Comp or LLV/SLV (MLH model)
energize. Ice production starts 4to 6 min. after Comp or LLV/SLV (MLH model) energize
depending on ambient and water conditions. As ice is produced, the water level in
the reservoir drops. UFS opens. Nothing happens at this time. When LFS opens, WV
energizes and rell cycle begins, FZT terminates, and FTstarts.
FZT: 30-Min. Freeze Safety Timer – FZT starts when UFS closes and terminates
when LFS opens. If LFS does not open within 30 min. of UFS closing, CB shuts down
the icemaker and sounds a 5-beep alarm. See "III.A.2.LED Lights and Audible Alarm
Safeties." To reset, turn the power supply off and on again. See "II.F. Diagnostic Tables"
for troubleshooting details.
Icemaker Diagnosis (CCR/GMPR): 5-min. ice purge timer terminates, CB "COMP"
LED is on and COMP or LLV/SLV (MLH model) energizes. If not, check for 5VDC
between CB K5 connector pin closest to CB K4 connector and CB K9connector
#5(W/O). If 5VDC is not present, replace CB. If 5VDC is present, check for 5VDC
between CB K5 connector pin closest to CB K4 connector and CB K9connector
#6(W/O). If 5VDC is present and CB "Comp" LED is off (CR, COMP, or LLV/SLV (MLH
model) not energized), replace CB. If 5VDC is not present, check for 115VAC between
CCR/GMPR terminal #7(O) to CCR/GMPR terminal #8(W) for 115VAC. If115VAC
is not present (GM not energized), see step 8 above. If 115VAC is present and CCR/
GMPR contacts are open (5VDCpresent between terminals #3(W/O) and #5(W/O)),
check CCR/GMPR solenoid voltage and solenoid continuity. Replace CCR/GMPR if
necessary.
Icemaker Diagnosis (COMP or LLV/SLV (MLH model)): If"COMP" LED is on and
COMP or LLV/SLV (MLH model) is not energized, check CB X1 relay BK or BR wire to
a neutral (W) and CB X1 relay V, BR, or R wire to a neutral (W) for 115VAC. If115VAC
is present on CB X1BK or BR wire and not on CBX1 V, BR, or R wire, replace CB.
If115VAC is present on CBX1V, BR, or R wire and COMP or LLV/SLV (MLH model) is
not energized, check for 115VAC at CB X1 Comp relay, Comp or LLV/SLV (MLH model).
Check Comp internal overload (motor protector), start relay, and capacitors.
Check LLV/SLV (MLH model) solenoid continuity.

22

10) Rell Cycle – "GM", "COMP", and "WTRIN" LEDs are on.
LFS opens. WVenergizes and 90-sec. FT starts. Comp or LLV/SLV (MLH model), GM,
CCR/GMPR, and FM/FMR continue. LFS closes. Nothing occurs at this time. Reservoir
continues to ll until UFS closes. When UFS closes, WV de-energizes, 90-sec. FT
terminates, and 30-min. FZT starts. If UFS remains open longer than 90 sec. after LFS
opens, FT exceeded and CB sounds a 1-beep alarm. WVremains energized until UFS
closes. Alarm resets automatically when UFS closes.
Diagnosis – Conrm that the water level has dropped and the UFS and LFS are open.
See "II.E.1. Float Switch Check." Check that "WTRIN" LED is on. IfLFS is open and
"WTRIN" LED is off, replace CB. If "WTRIN" LED is on, check that the reservoir lls.
Ifnot, check water supply line shut-off valve, water lters, and WVscreen. If"WTRIN"
LED is on and WV is off, check CB K2 #8(O) to a neutral (LBU) for 24VAC. If 24VAC
is not present, check CB K2 #9(W/R) to a neutral (LBU) for 24VAC. If 24VAC is
present on CB K2 #9 (W/R)and not on CB K2#8 (O), replace CB. If 24VAC is
present on CB K2#8(O),check continuity through WV solenoid. If open, replace WV.
IfWV is energized and rell exceeds FT with no water in the reservoir, check for DV
leaking. Ifreservoir is full and overowing check for open UFS. See "II.E. Float Switch
Check and Cleaning." If UFS is closed, check that WVdeenergizes. If not, check
CB K2 #8(O) to a neutral (LBU) for 24VAC. If 24VAC is present, replace CB. If WV
de-energizes and water continues to ll the reservoir, replace WV.
Note: Each time UFS closes, 30-min. freeze timer starts. The 30-min. freeze timer

resets when UFS closes again. If UFS does not close again within 30 min., CB
shuts down the unit and sounds a 5-beep alarm every 5 sec.

See "III.A.2 LED Lights and Audible Alarm Safeties."
FT: 90-Sec. Low Water Safety Timer – When LFS opens, 90-sec. low water safety
timer starts. If UFS does not close within 90 sec. after LFS opens (FTexceeded),
CBsounds a 1-beep alarm and a 90-sec. shutdown cycle starts
See "III.A.2.LED Lights and Audible Alarm Safeties." Comp or LLV/SLV (MLH model)
de-energizes. GM, CCR/GMPR, and EH continue. 90-sec. purge timer terminates, GM,
EH, and CCR/GMPR de-energize. WV and 1-beep alarm continue until UFS closes.

11) Drain Cycle
a) 1-in-1 Drain Cycle: DV energizes once every hour when the 1-in-1 drain cycle is

activated (S1 dip switch 4 in the "OFF" position (factory default position)). GM,
FM/FMR, Comp, LLV/SLV (MLH model), continue. DV energizes for 2 sec. every
hour. This setting is recommended for optimum icemaker performance. The 1-in-1
drain cycle allows any sediment to drain from the evaporator without interrupting the
icemaking process.

b) 1-in-12 Drain Cycle (optional): DV energizes once every 12 hours when the 1-in-12

drain cycle is activated (S1 dip switch 4 in the on position (optional)). 12-hour drain
cycle timer terminates, Comp or LLV/SLV (MLH model) de-energize. GM, and
FM/FMR continue. The 5-min. ice purge timer starts. When the 5-min. ice purge
timer terminates, GM and FM/FMR de-energize. 10-min. DT starts, DV energizes.
After 10-min. DT terminates, DV de-energizes icemaking process restarts and 12­hour drain cycle timer starts.

23

c) Manual Drain: Manual drain is used when servicing evaporator components and

cleaning and sanitizing the unit. When the unit is making ice and the control switch
is moved to the "DRAIN" position, there is a 3-sec. delay, then Comp or LLV/SLV
(MLH models) de-energize and the 5-min. ice purge timer begins. When the 5-min.
ice purge timer terminates, GM, and FM/FMR de-energize. DV energizes to drain
the evaporator and reservoir. To avoid the 5-min. shutdown delay, turn off the power
supply, then move the control switch to the "DRAIN" position. Turn on the power
supply. DV energizes to drain the evaporator and reservoir. DV de-energizes when
the control switch is moved to the "ICE" position.

10) Shutdown
a) BC1 (infrared sensor): When power is supplied to the icemaker, the green LED on

BC1 turns on. The green LED remains on constantly. As ice lls the storage bin to
the level of activating BC1, BC1 yellow LED turns on (ashing or steady). The yellow
LED ashes when ice is at the outer limit of its range and turns steady as ice nears.
After the yellow LED turns on (ashing or steady), BC1 shutdown delay timer (S1 dip
switch 1, 2, 3) starts. For a typical dispenser unit application, a 100-sec. shutdown
delay is recommended. When used with a standard Hoshizaki storage bin, any
shutdown delay setting is acceptable. See "III.B.2. BC1 (Infrared Sensor) Shutdown
Delay (S1 dip switch 1, 2, 3)." Once BC1 shutdown delay timer terminates, Comp or
LLV/SLV (MLH models) de-energize and the 5-min. ice purge timer starts. When
the 5-min. ice purge timer terminates, GM, CCR/GMPR, and FM/FMR de-energize.
Diagnosis: See "II.D.1. Bin Control 1 (infrared sensor) Check."

Note: When BC1 and BC2 are applied–If BC1 fails to shut down the icemaker, BC2

opens, CB shuts down the icemaker and sounds a 9-beep alarm.

b) BC(2) (mechanical stand-alone or backup):

BC (stand-alone): BC opens (actuator paddle engaged). CB shuts down the
icemaker within 10 sec.
BC2 (backup): BC2 opens (actuator paddle engaged). CB shuts down the icemaker
immediately and sounds a 9-beep alarm.
Diagnosis: See "II.D.2. Bin Control(2) (mechanical stand-alone or backup) Check."

Legend: BC1–bin control 1 (infrared sensor); BC(2)–bin control (2) (mechanical stand-alone

or backup); CB–control board; CCR–compressor control relay (formerly GMPR
gear motor protect relay); Comp–compressor; DV–drain valve; EH–evaporator
heater (-C model except FD-650); FM–fan motor; FMR–fan motor-remote;
GM–gear motor; GMR–gear motor relay; LFS–lower oat switch; LLV –liquid line
valve (MLH model); SLV –suction line valve (MLH model); UFS–upper oat switch;
WV–inlet water valve

24

C. Control Board Check

Before replacing a control board that does not show a visible defect and that you suspect
is bad, always conduct the following check procedure. This procedure will help you verify
your diagnosis.

1) Check CB S1 dip switch settings to assure that they are in the factory default position.
For factory default settings, see "III.B.1. Default Dip Switch Settings."
Note: S1 dip switch 7determines bin control application:
BC (mechanical stand-alone) or BC2 (mechanical backup only): S1 dip switch 7 in
the "OFF" position.
BC1 (infrared sensor stand-alone) or with BC2 (mechanical backup): S1 dip switch
7in the "ON" position.

2) Move the power switch to the "ON" position and move the control switch to the "ICE"
position. The "POWER OK" LED turns on. Diagnosis "POWER OK" LED: Check that
the CB "POWER OK" LED is on. If not, check for proper supply voltage (115VAC) input
to the control transformer (power switch, breaker, and fuse). Next, check for proper
low-voltage (24VAC) output from the control transformer and that the 1A fuse is good.
Check for 24VAC at CB K8 #1 (W/R) to CB K8 #2 (LBU). If 24VAC is present and the
"POWER OK" LED is off, replace CB.

3) BC1 (infrared sensor) Power Supply (K6 connector): CB supplies 20VDC to BC1
and BC1 green LED is on. Diagnosis: Check that BC1 green LED is on. If not, check
for 20VDC between CB K6 #1 (DBU) and CB K6 #3(BR). See Fig. 1. If 20VDC is not
present, replace CB. If 20VDC is present, conrm that the yellow LED is not ashing
or steady. If BC1 yellow LED is on or ashing, move ice away from lens. If no ice is
present, clean the lens with a warm, clean damp cloth. If cleaning the lens does not
work, replace BC1 (infrared sensor).

BC1 (infrared sensor) (20VDC) Closed
20VDC K6 #1 (DBU) to K6 #3 (BR)
20VDC K6 #1 (DBU) to K6 #2 (W)
0VDC K6 #2 (W) to K6 #3 (BR)

BC1 (infrared sensor) (20VDC)
Open (yellow LED ashing or steady)
20VDC K6 #1 (DBU) to K6 #3 (BR)
0VDC K6 #1 (DBU) to K6 #2 (W)
20VDC K6 #2 (W) to K6 #3 (BR)

K6 #3
Brown (BR)

K6 #2
White (W)

K6 #1
Dark Blue (DBU)

Fig. 1

25

Red Positive
Test Lead

3

20VDC

2
1

Black Negative
Test Lead

Multimeter

• K6 Connector

BC1 (Infrared Sensor)

4) 5VDC Output Checks:
CB K9 Connector: Control Switch (CB K9 #1 and #2) (open contacts for icemaking,
closed contacts for drain), High-Pressure Switch (CB K9 #3 and #4), Compressor
Control Relay/Gear Motor Protect Relay (K9 #5 and #6).
CB K8 Connector: Bin Control (2) (K8 #3 and #4) and Float Switch (K8 #5 (common),
#6 (lower), and #7 (upper)).
When checking 5VDC control voltage, always place the red positive test lead from
the multimeter to the CB white K5 pin closest to the CB red K4 connector. See Fig. 2.
Then place the black negative test lead from the multimeter to the corresponding pin to
complete the 5VDC check.

Red positive test lead
to K5 pin closest to K4

connector

Red Positive
Test Lead

5VDC

Multimeter

Black Negative
Test Lead

Control Board K9 Connector

Control Switch
white/black (W/BK)

High-Pressure Switch
yellow (Y) wires

Compressor Control Relay/
Gear Motor Protect Relay
(terminals #3 and #5)

white/orange (W/O)

Fig. 2

a) Control Switch – CB K9 #1 (W/BK) and CB K9 #2 (W/BK):

5VDC is present between CB white K5 connector, pin closest to CB red
K4 connector and CB K9 #1 (W/BK) at all times. If 5VDC is not present, replace
CB. When the control switch is in the "ICE" position, the control switch contacts
are open. 0VDC is present between CB white K5 connector, pin closest to CB red
K4 connector and CB K9 #2 (W/BK). When in the "ICE" position, 5VDC is present
between CB K9 #1 (W/BK) to CB K9 #2 (W/BK). When the control switch is in the
"DRAIN" position, the control switch contacts are closed. 5VDC is present between
CB white K5 connector, pin closest to CB red K4 connector, to CB K9 #1 (W/BK)
or#2(W/BK). If 5VDC is not present, replace CB. 0VDC is present from CB K9
#1(W/BK) to CB K9 #2 (W/BK).

b) High-Pressure Switch – CB K9 #3 (Y) and CB K9 #4 (Y):

5VDC is present between CB K5 connector, pin closest to CB red K4 connector and
CB K9 #3 (Y) at all times. When the high-pressure switch is closed, 5VDC is present
between CB K5 pin closest to CB K4 connector to CB K9 #3 (Y) and CB K9 #4 (Y).
If 5VDC is not present, replace CB. When the high-pressure switch is closed, 0VDC
is present at CB K9 #3 (Y) to CB K9 #4 (Y). When the high-pressure switch is open,
5VDC is present at CB K9 #3 (Y) to CB K9 #4 (Y). If the high-pressure switch is open
and CB is not in alarm, replace CB. If5VDC is present at CB K9 #3 (Y) and not at
CB K9 #4 (Y), the high-pressure switch is open and CB sounds a 3-beep alarm.
Check continuity across the high-pressure switch (CB K9 #3 (Y) and CB K9 #4 (Y)).

26

c) Compressor Control Relay/Gear Motor Protect Relay (CCR/GMPR) –

CB K9 #5(W/O) and CB K9 #6 (W/O): 5VDC is present from CB white K5 connector,
pin closest to CB red K4 connector to CB K9 #5 (W/O) at all times. If 5VDC is not
present, replace CB. When CCR/GMPR terminals #3 (W/O) and #4 (W/O) are open
(CCR/GMPR de-energized), 5VDC is present between CB K9 #5 (W/O) and CB K9
#6 (W/O). When CCR/GMPR terminals #3(W/O) and #4 (W/O) are closed (CCR/
GMPR energized), 5VDC is present between CB K9 #5 (W/O) and CB K9 #6 (W/O).
When CCR/GMPR terminals #3 (W/O) & #5 (W/O) are open CB may be in an
8-beep alarm. See "III.A.2. LED Lights and Audible Alarm Safeties."

d) Bin Control (2) (mechanical stand-alone or backup) –

CB K8 #3 (GY) and CB K8 #4(GY): 5VDC is present from CB white K5 connector,
pin closest to CB red K4 connector to CB K8 #3 (GY) at all times. If 5VDC is not
present, replace CB. When BC(2) is closed (calling for ice), 5VDC is present from
CB white K5 connector, pin closest to CB red K4 connector, to CB K8 #3 (GY) and
CB K8 #4(GY). If 5VDC is not present to either CB K8 #3 (GY) or CB K8 #4(GY),
replace CB. If 5VDC is present at CB K8 #3 (GY) and not to CB K8 #4 (GY), BC(2) is
open. See "II.D.2. Bin Control (2) (mechanical stand-alone or backup) Check."

e) Float Switch (LFS and UFS) – CB K8 #5 (BK) (common), CB K8 #6(R) (upper),

and CB K8 #7 (BU) (lower): 5VDC is present from CB white K5 connector pin closest
to CB red K4 connector to CB K8 #5(BK) (common) at all times. If not, replace CB.
5VDC is present from CB white K5 connector pin closest to CB red K4connector
to CB K8 #6 (R) (upper) and CB K8 #7 (BU) (lower) when FS is open. If 5VDC
is present between CB K8 #5 (BK) and CB K8 #6 (R) (upper) or CB K8 #7 (BU)
(lower), FS is open. Forfurther FS diagnostics, see "II.E. Float Switch Check and
Cleaning."

5) Fill "WTRIN" LED is on: 24VAC is present at CB K2 #9 (W/R) at all times. If not,
conrm 24VAC from CB K2 #9(W/R) to a neutral (LBU). When LFS open at startup
or opens during normal operation, "WTRIN" LED turns on, ll timer (FT) starts, freeze
timer (FZT) terminates (only during normal operation), and WV energizes. If LFS is
open and "WTRIN" LED is off, conrm LFS status. See "II.E. Float Switch Check and
Cleaning." If LFS is open and "WTRIN" LED is off, replace CB. If "WTRIN" LED is on
and WV is not energized, check for 24VAC at CB K2 #8(O) to a neutral (LBU). If24VAC
is not present at CB K2 #8(O), replace CB. "WTRIN" LED turns off once UFS closes.
Ifnot, conrm UFS status. See "II.E. Float Switch Check and Cleaning." IfUFS is
closed and "WTRIN" LED is on, replace CB. If "WTRIN" LED is off and WV is open,
check for 24VAC at CB K2 #8 (O). If 24VAC is present at CB K2 #8 (O), replace CB.
If24VAC is not present, check WV diaphragm.

6) Ice Purge Cycle "GM" LED is on: When UFS closes, GM delay timer starts (5 or
30sec. depending on CB S1 dip switch #7). Once GM delay timer terminates, "GM"
LED turns on, GM and EH (-C model except FD-650) energize and 5-min. ice purge
timer starts. If GM does not energize 30 sec. after UFS closes, conrm UFS status.
See "II.E. Float Switch Check and Cleaning." If UFS is closed and GM LED does not
turn, replace CB. If "GM" LED is on and GM and EH are off, check for 115VAC from
CBK1#2to a neutral (W). If 115VAC is not present, check 115VAC power supply
connections from power switch. If 115VAC is present, check for 115VAC from CB K1
#3to a neutral (W). If115VAC is present on CB K1 #2and not on CB K1 #3, replace
CB.

27

7) Freeze Cycle "GM" and "COMP" LED are on: The 5-min. ice purge timer terminates
or the ice purge cycle bypass button ("SERVICE") is pressed, "COMP" LED turns on.
Tobypass the 5-min. Ice Purge Cycle, press the "SERVICE" button on CB after the
"GM" LED turns on. WARNING! Risk of electric shock. Care should be taken not
to touch live terminals. 115VAC is present between CB X1 relay power supply brown
(BR) or black (BK) wire and neutral (W) at all times. If not, check 115VAC power supply
wire connections from power switch. If"COMP" LED is not on after 5-min. ice purge
timer terminates, replace CB.
When "COMP" LED turns on, CR (if applicable) and compressor energize. If "COMP"
LED is on and compressor relay (CR) (if applicable) and compressor are not, check for
115VAC from CB X1 relay power supply brown (BR) or black (BK) wire to neutral (W).
If 115VAC is present, check X1 relay red (R), violet (V), or brown (BR)(FD-650 only) to
neutral (W). If 115VAC is present on X1 relay brown (BR) or black (BK) and not on X1
relay red (R), violet (V), or brown (BR)(FD-650 only), replace CB.

8) Rell "WTRIN" LED is on: See "5) Fill "WTRIN" LED is on:" above.

Legend: BC1–bin control 1 (infrared sensor); BC(2)–bin control (2) (mechanical stand-alone

or backup); CB–control board; CR–compressor relay; CCR/GMPR–compressor
control relay/gear motor protect relay; EH–evaporator heater (-C model except
FD-650); FS–oat switch; GM–gear motor; LFS–lower oat switch; UFS–upper
oat switch; WV–inlet water valve

28

Control Board

• K9 Connector (5VDC)

• "COMP" LED
(X1 Relay)

• "GM" LED
(X2 Relay)

GM

• K1 Connector

(115VAC)

GM, CCR/GMPR, EH,
FM, FMR #3
115VAC Input #2

• "FLUSH" LED

(X3 Relay) (drain)

DV

• "WTRIN" LED

(X4 Relay)

WV

Comp, LLV, SLV

• K2 Connector

(24VAC)

Drain Valve
#10 (W/BU)

Control Transformer
24VAC Input
#9 (white/red)

Inlet Water Valve
#8 (O)

Control Switch
#1 to #2 (white/black)

(DRAIN)

High-Pressure Switch
#3 to #4 (yellow)

Compressor Control Relay Circuit/Gear
Motor Protect Relay Circuit
#5 to #6 (white/orange)

• S2 "SERVICE" Button
(Ice Purge Cycle Bypass)

• K8 Connector

(24VAC and 5VDC)

Control Transformer
24VAC Input
#1 (white/red)

Control Transformer
24VAC Neutral
#2 (light blue)

Bin Control (2) (mechanical)
#3 & #4 (gray) (5VDC)

Float Switch-Common
#5 (black) (5VDC)

Upper Float Switch
#6 (red) (5VDC)

Lower Float Switch
#7 (blue) (5VDC)

Control Transformer
24VAC Input
#7 (white/red)

Water Dispensing
Valve, Agitation
Motor, and Ice
Dispensing LEDs
(not used on
these models)

5VDC common terminals

• K3 Connector-Open

• K4 Connector-Open

• K5 Connector-Open

• J2 Connector-Open

Control Board

Part Number

Fig. 3

29

• K7 Connector-Open

• "POWER OK" LED

• S1 Dip Switch

3 2 1

• K6 Connector (20VDC)
Bin Control 1 (infrared sensor)
(dark blue)
(white, signal (common))
(brown (ground))

2A48054-01

D. Bin Control Check

1. Bin Control 1 (infrared sensor) Check

IMPORTANT

Make sure CB S1 dip switch 7 is in the "ON" position. This allows the control board
to monitor BC1 (infrared sensor) along with BC2 (mechanical) backup bin control.

1) Turn off the power supply.

2) Remove the front panel, top panel, and control box cover.

3) Conrm that CB S1 dip switch 1, 2, 3 are in the proper position for your application.
See "III.B.2. BC1 (Infrared Sensor) Shutdown Delay (S1 dip switch 1, 2, 3)."

4) Conrm that BC1 is connected to CB K6 connector. Wipe down BC1 lens with a warm,
clean, damp cloth. If the bottom of the icemaker is not accessible in your application,
remove the thumbscrew securing the BC1 housing, then remove the housing from the
base. See Fig. 4.

5) Move the control switch to the "ICE" position, then move the power switch to the "ON"
position.

6) Turn on the power supply to start the automatic icemaking process. Check that BC1
green LED is on. The BC1 green LED conrms 20VDC power from CB to BC1 and
remains on constantly. Diagnosis: If the BC1 green LED is not on, conrm 20VDC
at CB K6 #1 (DBU) to CB K6 #3 (BR). If 20VDC is present and the BC1 green LED is
off, replace BC1. If not, see step "3) BC1 (infrared sensor) Power Supply," under "II.C.
Control Board Check.

7) Make sure CB "GM" LED is on. There is a delay of at least 30 sec. before the "GM" LED
turns on after power-up. After CB "GM" LED turns on, press CB "SERVICE" button to
bypass the 5-min. ice purge cycle. WARNING! Risk of electric shock. Care should be

taken not to touch live terminals.

BC1 (infrared sensor)

Connector

LEDs

Thumbscrew

Housing

Lens

(20VDC from
K6 connector on
control board)

Housing

LEDs

Lens

Fig. 4

30