Hoshizaki DCM-500BWH, DCM-500BAH User Manual

Hoshizaki America, Inc.

Hoshizaki

Cubelet Icemaker / Dispenser

Models
DCM-500BAH

“A Superior Degree

of Reliability”

www.hoshizaki.com

DCM-500BAH-OS
DCM-500BWH
DCM-500BWH-OS

SERVICE MANUAL

®

Number: 73165
Issued: 7-30-2008

IMPORTANT

Only qualied service technicians should attempt to install, service, or maintain
this icemaker. No service or maintenance should be undertaken until the
technician has thoroughly read this Service Manual. Failure to service and
maintain the equipment in accordance with this manual may adversely affect
safety, performance, and warranty coverage.

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

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

HOSHIZAKI AMERICA, INC.
618 Highway 74 South
Peachtree City, GA 30269

Attn: Hoshizaki Technical Support Department

Phone: [phone] Technical Service
[phone]
Fax: [phone]
[phone]
E-mail: [e-mail]

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 icemaker is serviced or
maintenance operations are performed. Only qualied service technicians
should install, service, and maintain the icemaker. Read the warnings
contained in this booklet carefully as they give important information regarding
safety. Please retain this booklet for any further reference that may be
necessary.

CONTENTS

I. Specications ...................................................................................................................... 5

A. Icemaker ....................................................................................................................... 5

1. DCM-500BAH .......................................................................................................... 5

2. DCM-500BAH-OS ................................................................................................... 6

3. DCM-500BWH ......................................................................................................... 7

4. DCM-500BWH-OS .................................................................................................. 8

II. General Information ........................................................................................................... 9

A. Construction .................................................................................................................. 9

B. Ice Making Unit ............................................................................................................11

C. Sequence of Operation ............................................................................................... 12

1. Fill Cycle ................................................................................................................. 12

2. Ice Purge Cycle (60 seconds) ................................................................................ 12

3. Freeze Cycle .......................................................................................................... 12

4. Drain Cycle ............................................................................................................ 12

5. Shutdown ............................................................................................................... 12

D. Control Board .............................................................................................................. 14

1. Control Board Layout ............................................................................................. 15

a) DCM-500BAH, DCM-500BWH ......................................................................... 15

b) DCM-500BAH-OS, DCM-500BWH-OS............................................................. 16

2. Features ................................................................................................................. 17

3. Controls and Adjustments ..................................................................................... 18

4. Control Board Check Procedure ............................................................................ 18

E. Float Switch ................................................................................................................. 20

III. Technical Information ...................................................................................................... 21

A. Water Circuit and Refrigeration Circuit ........................................................................ 21

B. Wiring Diagrams .......................................................................................................... 23

1. DCM-500BAH, DCM-500BWH .............................................................................. 23

2. DCM-500BAH-OS, DCM-500BWH-OS ................................................................ 24

C. Sequence of Electrical Circuit – Ice Making ................................................................ 25

1. Fill Cycle ................................................................................................................ 25

2. Ice Purge Cycle ..................................................................................................... 26

3. Freeze Cycle ......................................................................................................... 27

4. 12 Hour Drain Cycle / Drain Switch ....................................................................... 28

5. Shutdown ............................................................................................................... 29

6. Low Water Safety .................................................................................................. 30

7. High Pressure Switch ............................................................................................ 31

D. Sequence of Electrical Circuit – Dispensing .............................................................. 32

1. Continuous Dispense ............................................................................................. 32

2. Portion Dispense ................................................................................................... 33

3

E. Performance Data ....................................................................................................... 34

1. DCM-500BAH(-OS) ................................................................................................ 34

2. DCM-500BWH(-OS) .............................................................................................. 35

IV. Service Diagnosis ........................................................................................................... 36

A. Diagnostic Procedure .................................................................................................. 36

B. Ice Production Check .................................................................................................. 37

C. Diagnostic Charts ....................................................................................................... 38

1. No Ice Production ................................................................................................... 38

2. Low Ice Production ................................................................................................ 41

3. Other ...................................................................................................................... 42

4. Dispensing ............................................................................................................. 43

5. Opti Serve (OS) Sensors ....................................................................................... 44

V. Removal and Replacement of Components .................................................................... 46

A. Service for Refrigerant Lines ....................................................................................... 46

1. Refrigerant Recovery ............................................................................................. 46

2. Brazing .................................................................................................................. 46

3. Evacuation and Recharge (R-404A) ...................................................................... 47

B. Removal and Replacement of Compressor ................................................................. 48

C. Removal and Replacement of Expansion Valve .......................................................... 49

D. Removal and Replacement of Evaporator Assembly Components ............................. 50

1. Upper Bearing Wear Check .................................................................................. 51

2. Removal and Replacement of Extruding Head ...................................................... 51

3. Removal and Replacement of Auger ..................................................................... 52

4. Removal and Replacement of Evaporator ............................................................. 52

5. Removal and Replacement of Mechanical Seal and Lower Housing ................... 54

6. Removal and Replacement of Gear Motor ............................................................ 55

E. Removal and Replacement of Self-Contained Air-Cooled Condenser ........................ 56

F. Removal and Replacement of Water-Cooled Condenser ............................................. 57

G. Removal and Replacement of Water Regulating Valve - Water-Cooled Model Only ... 58

H. Adjustment of Water Regulating Valve - Water-Cooled Model Only ............................. 59

I. Removal and Replacement of Fan Motor ..................................................................... 59

J. Removal and Replacement of Inlet or Dispensing Water Valve ................................... 60

K. Removal and Replacement of Drain Valve .................................................................. 60

L. Removal and Replacement of Dispensing System ...................................................... 61

1. Dispensing Auger and Agitator ............................................................................... 61

2. Dispensing or Agitating Motor ................................................................................ 61

VI. Cleaning and Maintenance ............................................................................................. 63

A. Cleaning and Sanitizing Instructions ........................................................................... 63

1. Water System ......................................................................................................... 64

a) Cleaning Solution ............................................................................................... 64

b) Cleaning Procedure ............................................................................................ 64

c) Sanitizing Solution .............................................................................................. 65

d) Sanitizing Procedure - Following Cleaning Procedure ....................................... 65

2. Dispensing Components ....................................................................................... 65

a) Cleaning Solution ............................................................................................... 65

b) Sanitizing Solution .............................................................................................. 65

c) Cleaning and Sanitizing Procedure ..................................................................... 65

B. Maintenance ................................................................................................................ 67

C. Preparing the Icemaker for Long Storage ................................................................... 68

4

I. Specications

A. Icemaker

1. DCM-500BAH

AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 7.9 RLA 51 LRA
GEAR MOTOR 120 V 2.4 FLA 1/4 HP
FAN MOTOR 120 V 1.0 FLA 50 W
AGITATING MOTOR 120 V 0.9 FLA 55 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHERS 120 V 0.2 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACITY 20 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp. (°F) 50 70 90
lbs./day ( kg/day ) 70 *535 (243) 510 (231) 485 (220)
Reference without * marks 80 461 (209) 438 (199) 416 (189)

90 396 (179) *385 (175) 358 (162)

100 340 (154) 323 (147) *304 (138)
SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Apprx. 90% Ice (90/70° F, CONDUCTIVITY 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 40 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 1055 (6.6) 985 (4.4)
POTABLE WATER 46 (11.9) 64 (11.9)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 26" x 22-1/2" x 40" ( 661 x 571 x 1016 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT NET 251 lbs. (114 kg), Shipping 276 lbs. (125 kg)
CONNECTIONS - ELECTRIC Permanent Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT x2
ICE MAKING SYSTEM Auger type
HARVESTING SYSTEM Direct Driven Auger ( 1/4 HP Gear Motor )
ICE MAKING WATER CONTROL Float Switch
COOLING WATER CONTROL N/A
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS43C2E-CAA-219
CONDENSER Air-cooled, Fin and tube type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R404A 1 lb 4.1 oz. (570g)
DESIGN PRESSURE High 460 PSIG Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Auto-reset Thermal Protector

Fuse
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Timer
ACCESSORIES - SUPPLIED Spare Fuse

- REQUIRED Legs
OPERATING CONDITIONS VOLTAGE RANGE 104-127 V

AMBIENT TEMP. 45-100 F

WATER SUPPLY TEMP. 45-90 F

WATER SUPPLY PRESSURE 10-113 PSIG

Note: We reserve the right to make changes in specications and design without prior

notice.

5

2. DCM-500BAH-OS

AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 7.9 RLA 51 LRA
GEAR MOTOR 120 V 1.6 FLA 1/6 HP
FAN MOTOR 120 V 0.6 FLA 30 W
AGITATING MOTOR 120 V 0.9 FLA 55 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHERS 120 V 0.2 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACITY 20 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp. (°F) 50 70 90
lbs./day ( kg/day ) 70 *525 (238) 510 (231) 485 (220)
Reference without * marks 80 461 (209) 438 (199) 416 (189)

90 396 (179) *385 (175) 358 (162)

100 340 (154) 323 (147) *304 (138)

SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Apprx. 90% Ice (90/70° F, CONDUCTIVITY 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 40 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 1055 (6.6) 985 (4.4)
POTABLE WATER 46 (11.9) 64 (11.9)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 26" x 22-1/2" x 40" ( 661 x 571 x 1016 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT NET 251 lbs. (114 kg), Shipping 276 lbs. (125 kg)
CONNECTIONS - ELECTRIC Permanent Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT x2
ICE MAKING SYSTEM Auger type
HARVESTING SYSTEM Direct Driven Auger ( 1/6 HP Gear Motor )
ICE MAKING WATER CONTROL Float Switch
COOLING WATER CONTROL N/A
DISPENSER CONTROL SYSTEM Photoelectric Sensor (Infrared)
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS43C2E-CAA-219
CONDENSER Air-cooled, Fin and tube type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R404A 1 lb 4.1 oz. (570g)
DESIGN PRESSURE High 460 PSIG Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Auto-reset Thermal Protector

Fuse
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Timer
ACCESSORIES - SUPPLIED Spare Fuse

- REQUIRED Legs
OPERATING CONDITIONS VOLTAGE RANGE 104-127 V

AMBIENT TEMP. 45-100 F

WATER SUPPLY TEMP. 45-90 F

WATER SUPPLY PRESSURE 10-113 PSIG

Note: We reserve the right to make changes in specications and design without prior

notice.

6

3. DCM-500BWH

)

AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 7.9 RLA 51 LRA
GEAR MOTOR 120 V 2.4 FLA 1/4 HP
AGITATING MOTOR 120 V 0.9 FLA 55 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHERS 120 V 0.2 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACITY 20 A
APPROXIMATE ICE PRODUCTION Ambient
PER 24 HR. Temp. (°F)
lbs./day ( kg/day ) 70 * 567 (257) 549 (249) 539 (244)
Reference without * marks 80 529 (240) 519 (2335

90 500 (227) * 495 (224) 481 (218)

100 472 (214) 464 (210) * 428 (194)
SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Approx. 90% Ice (90/70° F, Conductivity 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 40 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F
ELECTRIC W (kWH/100 lbs.) 967 (4.7)
POTABLE WATER 60 (12)
WATER - COOLED CONDENSER 352 (71.2)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 26" x 22-1/2" x 40" (661 x 571 x 1016 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT Net 245 lbs. (111 kg), Shipping 269 lbs. (122 kg)
CONNECTIONS - ELECTRIC Permanent Connection

- WATER SUPPLY Inlet 1/2" FPT Condenser Inlet 1/2"FPT

- DRAIN Outlet 3/4" FPT x2 Condenser Outlet 3/8" FPT
ICE MAKING SYSTEM Auger type
HARVESTING SYSTEM Direct Driven Auger ( 1/4 HP Gear Motor )
ICE MAKING WATER CONTROL Float Switch
COOLING WATER CONTROL Automatic Water Regulator
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS43C2E-CAA-219
CONDENSER Water Cooled, Double Tube Type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R404A 14.1 oz. (400g)
DESIGN PRESSURE High 460 PSIG Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Auto-reset Thermal Protector

Fuse
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Timer
ACCESSORIES - SUPPLIED Spare Fuse

- REQUIRED Legs
OPERATING CONDITIONS VOLTAGE RANGE 104-127 V

AMBIENT TEMP. 45-100°F

WATER SUPPLY TEMP. 45-90°F

WATER SUPPLY PRESSURE 10-113 PSIG

991 (4.1)

251 (44.3)

WATER TEMP. (°F)

50 70 90

509 (231)

70/50°F

68 (12)

Note: We reserve the right to make changes in specications and design without prior

notice.

7

4. DCM-500BWH-OS

AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 7.9 RLA 51 LRA
GEAR MOTOR 120 V 1.6 FLA 1/6 HP
AGITATING MOTOR 120 V 0.9 FLA 55 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHERS 120 V 0.2 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACITY 20 A
APPROXIMATE ICE PRODUCTION Ambient
PER 24 HR. Temp. (°F)
lbs./day ( kg/day ) 70 * 567 257
Reference without * marks 80 529 240 519 235 509 231

90 500 227 * 495 224 481 218

100 472 214 464 210 * 428 194
SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Approx. 89% Ice (90/70° F, CONDUCTIVITY 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 40 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F
ELECTRIC W (kWH/100 lbs.) 930 (4.8)
POTABLE WATER 56 (12)
WATER - COOLED CONDENSER 465 (100)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 26" x 22-1/2" x 40" (661 x 571 x 1016 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT Net 245 lbs. (111 kg), Shipping 269 lbs. (122 kg)
CONNECTIONS - ELECTRIC Permanent Connection

- WATER SUPPLY Inlet 1/2" FPT Condenser Inlet 1/2"FPT

- DRAIN Outlet 3/4" FPT x2 Condenser Outlet 3/8" FPT
ICE MAKING SYSTEM Auger type
HARVESTING SYSTEM Direct Driven Auger ( 1/6 HP Gear Motor )
ICE MAKING WATER CONTROL Float Switch
COOLING WATER CONTROL Automatic Water Regulator
DISPENSE CONTROL SYSTEM Photoelectric Sensor (Infrared)
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS43C2E-CAA-219
CONDENSER Water Cooled, Double Tube Type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R404A 14.1 oz. (400g)
DESIGN PRESSURE High 460 PSIG Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Auto-reset Thermal Protector

Fuse
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Timer
ACCESSORIES - SUPPLIED Spare Fuse

- REQUIRED Legs
OPERATING CONDITIONS VOLTAGE RANGE 104-127 V

AMBIENT TEMP. 45-100°F

WATER SUPPLY TEMP. 45-90°F

WATER SUPPLY PRESSURE 10-113 PSIG

70/50°F

985 (4.0)

285 (52)

WATER TEMP. (°F)

50 70 90

549 249 539 244

65 (12)

Note: We reserve the right to make changes in specications and design without prior

notice.

8

II. General Information

A. Construction

1. DCM-500BAH(-OS)

Expansion Valve

Evaporator Assembly

Inlet Water Valve

Float Switch

Reservoir

Control Box

Power Switch

Door Switch

Gear Motor

Spout A

Spout B

Drain Water Valve

Storage Bin

Agitator

Ice Dispensing
Auger

Control Switch

Dispense Mode Switch

Air-Cooled

Condenser

Shutter Assembly

Drier

Agitating Motor

Dispensing Motor

Compressor

Dispensing Water
Valve

Spout Cover

9

2. DCM-500BWH(-OS)

Inlet Water Valve

Reservoir

Control Box

Power Switch

Door Switch

Gear Motor

Spout A

Evaporator Assembly

Float Switch

Expansion Valve

Spout B

Drain Water Valve

Storage Bin

Agitator

Ice Dispensing
Auger

Control Switch

Dispense Mode Switch

Shutter Assembly

Water-Cooled

Condenser

Drier

Agitating Motor

Dispensing Motor

Compressor

Dispensing Water
Valve

Spout Cover

10

B. Ice Making Unit

1. DCM-500BAH(-OS), DCM-500BWH(-OS)

Extruding Head and
Upper Bearing

Auger

Cylinder

Evaporator

Insulation

Mechanical-Seal

Cubelet Cutter

Allen Head Cap Screw

Washer

Gear Motor

O-Ring

Spline Coupling

Allen Head Cap Screw
with Washer

Housing and
Lower Bearing

Hex Head Bolt

with Washer

11

C. Sequence of Operation

The steps in the sequence are as outlined below. When power is supplied, the power
switch is in the "ON" position, the door switch is engaged, and the control switch is in the
"ICE" position, the "POWER" LED on the control board comes on.

1. Fill Cycle

WV opens and the reservoir lls with water until UF/S closes. Note: GM will not start
unless UF/S is closed. For details, see "IV. Service Diagnosis".

2. Ice Purge Cycle (60 seconds)

"GM" LED is on. WCR energizes, closing the low water safety circuit and de-energizing
the WV. GM and GMPR energize. GM runs for 60 seconds to clear any ice from the
evaporator.

3. Freeze Cycle

"COMP", "GM" LEDs are on. Comp and FMS energize. As the water in the evaporator
cools, ice starts forming within 4 to 6 minutes. This time frame depends on the inlet water
and ambient temperature conditions. UF/S and LF/S operate WV as needed to continue
the ice making process. This continues until BC shuts the icemaker down or power is
turned off to the icemaker.

4. Drain Cycle

12 hour DT activates, "FLUSH" LED is on after 150 second shutdown sequence. Comp
and FMS de-energize 90 seconds after the 12 hour DT activates, GMPR and GM
de-energize 60 seconds later. DV then energizes and remains energized for 20 minutes.

5. Shutdown

BC is activated and a 150 second shutdown sequence begins. After BC has been
open for 90 seconds, Comp and FMS de-energize, AM energizes for 0.6 seconds, and
60 seconds later GM de-energizes.

Legend: AM–agitating motor; BC–bin control; Comp–compressor; DT–drain timer;
FMS–self-contained fan motor; GM–gear motor; GMPR–gear motor protect
relay; LF/S–lower oat switch; UF/S–upper oat switch; WCR–water control
relay; WV–inlet water valve

12

Low Water Safety

If rell > 90 sec. FT, 150 second

shutdown sequence begins

150 sec. Shutdown Sequence

Rell

(90 seconds)

3. Freeze Cycle

GM off

60 seconds

Comp off

90 seconds

UF/S open

LF/S closed

UF/S open

GMPR off

WV continues until

UF/S closes

FMS off

WV continues

GM continues

GMPR continues

FT exceeded

Comp continues

FMS continues

GM continues

GMPR continues

UF/S closed (WV off)

WCR on

FT off (90 sec.)

WV off

Comp continues

LF/S open (WV on)

WCR off

FT started (90 sec.)

WV on

Comp continues

WV continues

FMS continues

FMS continues

GM continues

GM continues

GMPR continues

GMPR continues

4. Ice Level Lowered

3. Icemaker is Off

See "1. Fill Cycle" above

Legend:

BC - bin control

Comp - compressor

DC - drain cycle

DT - drain timer

DV - drain valve

FMS - self-contained fan motor

4. 12 hour DC - Restart

See "1. Fill Cycle" above

3. Drain Cycle

DV on for 20 minutes

FT - ll timer (low water safety)

GM - gear motor

BC closedor20 Min. DT off (DC only)

GM off

GMPR off

GMPR - gear motor protect relay

DV on (DC only)

LF/S - lower oat switch

UF/S - upper oat switch

DV off (DC only)

12 hour DT reset (DC only)

WCR - water control relay

WV - inlet water valve

DCM-500BAH(-OS), DCM-500BWH(-OS) Sequence Flow Chart and Component Operation

60 seconds

Comp on

FMS on

WCR continues

GM continues

GMPR continues

4. 12 Hour Drain Cycle

DV opens for 20 minutes every 12 hours

See "3. 12 Hour Drain Cycle" below.

2. Ice Purge Cycle

1. Fill Cycle

60 seconds

WV on

LF/S closed

UF/S closed (WV off)

UF/S open

WCR on

WV off

GM on

GMPR on

2. Ice Purge Cycle

150 seconds

1. Bin Full

2. Ice Purge Cycle

90 seconds

1. Drain Cycle initiates

Comp off

FMS off

GM continues

GMPR continues

BC open or DC starts

Comp continues

FMS continues

GM continues

GMPR continues

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

The "DRAIN" position on the control switch is used when cleaning and sanitizing the unit. This allows

cleaner and sanitizer to drain from the reservoir and evaporator assembly. When switching to the "DRAIN"

position during the freeze cycle, the drain valve does not energize until the 150 second shutdown sequence

terminates (2. Shutdown & Restart).

Note: To bypass the 150 second shutdown sequence, move the power switch to the "OFF" position, place the

control switch in the "DRAIN" position, then move the power switch back to the "ON" position.

Shutdown & Restart

1. Startup

Power switch "ON"

Control switch in "ICE"

2. Shutdown & Restart

3. 12 Hour Drain Cycle

13

D. Control Board

• A Hoshizaki exclusive solid-state control board is employed in DCM-500BAH,
DCM-500BAH-OS, DCM-500BWH, and DCM-500BWH-OS Cubelet Icemaker /
Dispensers.

• All models are pretested and factory-adjusted.

CAUTION

1. Fragile, handle very carefully.

2. The control board contains integrated circuits, which are susceptible to
failure due to static discharge. It is especially important to touch the metal
part of the unit before handling or replacing the board.

3. Do not touch the electronic devices on the control board or the back of the
control board to prevent damage to the control board.

4. Do not change wiring and connections. Especially, never misconnect
terminals.

5. Always replace the whole control board if it goes bad.

6. Do not short out power supply to test for voltage.

14

1. Control Board Layout

a) DCM-500BAH, DCM-500BWH

Flush Switch
Must be left in the "P" position,
otherwise the internal drain
timer will not operate.

Counter Reset Button (not
used in this application)

High
Pressure
Switch

Dispensing
Components
See "III.
B. Wiring
Diagrams"
for details.

Bin Control,
Control
Switch,
Low Water
Safety

10.5V
Transformer

Portion Control
Timer

"FLUSH" LED
(X5 Relay)
Drain Valve

24V Supply Out

Drain Valve
24V Out

Microprocessor (board revision level
indicated by last 2 digits on label)

"DM" LED
(X4 Relay)
Shutter Solenoid,
Dispensing Auger
Motor

115V In

24V In

Dispensing Motor
115V Out

"AM" LED
(X3 Relay)
Agitating Motor

"COMP" LED
(X2 Relay)
Compressor,
Fan Motor

115V In

Agitating Motor
115V Out

"GM" LED
(X1 Relay)
Gear Motor

Gear Motor
Protect Relay
Circuit

"POWER" LED
(lights when
power is supplied
to the board)

115V In

Gear Motor
115V Out

Control Board

Part Number 2A1592-01

15

b) DCM-500BAH-OS, DCM-500BWH-OS

Flush Switch
Must be left in the "P" position,
otherwise the internal drain
timer will not operate.

Counter Reset Button (not
used in this application)

Dispensing Components
See "III.B. Wiring Diagrams"
for details.

Bin Control,
Control Switch,
Low Water Safety

High
Pressure
Switch

10.5V
Transformer

Portion Control
Timer

"FLUSH" LED
(X6 Relay)
Drain Valve

24V Supply Out

Drain Valve
24V Out

"WTR" LED
(X5 Relay)
Dispensing
Water Valve

24V In

Dispensing
Water Valve
24V Out

Microprocessor (board revision level
indicated by last 2 digits on label)

"ICE" LED
(X4 Relay)
Shutter Solenoid,
Dispensing Auger
Motor

24V In

Dispensing Motor
115V Out

115V In

"AM" LED
(X3 Relay)
Agitating Motor

"COMP" LED
(X2 Relay)
Compressor,
Fan Motor

115V In

Agitating Motor
115V Out

"POWER" LED
(lights when
power is supplied
to the board)

"GM" LED
(X1 Relay)
Gear Motor

Gear Motor
Protect Relay
Circuit

115V In

Gear Motor
115V Out

Control Board

Part Number 2A2649-01

16

2. Features

The control board provides the following safeguards:

•Provides component protection during low water supply.

•Purges remaining ice in the evaporator at startup and shutdown.

•Providesshortcycleprotectionforthecompressor.

a) LED Lights

The "POWER" LED indicates control voltage and will remain on unless a control
voltage problem occurs. An LED illuminates for each relay as it is energized. For more
information, see "II.C. Sequence of Operation."

Icemaking

Cycle (Relay) LED

Fill POWER only WV N/A As Needed
Ice Purge (X1) GM GM 60 seconds N/A

Freeze (X1, X2) GM, COMP

Drain Valve (X6) FLUSH DV 20 Minutes Every 12 Hours

Relay LED

Push Button

Ice Dispense (X4)

Agitating Motor (X3) AM AM .6 seconds

Water Dispense (X5)
(Opti Serv Only)

DM

Opti Serv

ICE

WTR WTR N/A N/A

Energized

Components

GM, Comp,
FMS

Dispensing

Energized

Component

IDM

Time LEDs are OnFrequency LEDs are

On

N/A N/A

Time LEDs are OnFrequency LEDs are

On

60 seconds
maximum

N/A

Every 12 seconds of
accumulative dispense
time

Legend: AM–agitating motor, Comp–compressor; DV–drain valve; FMS–self-contained
fan motor; GM–gear motor; IDM–ice dispensing motor, shutter solenoid;
WTR–dispensing water valve; WV–inlet water valve

17

3. Controls and Adjustments

a) Portion Control

When the dispense mode switch is placed in the "PORTION" position, a variable resistor
(located on the control board) controls the ice dispense time.

The gures on the label indicate dispensing time (sec.). When shipped, the portion
control is set at the minimum dispensing time (0.6 sec.).

DCM-500BAH(-OS), DCM-500BWH(-OS). . . . . . .Approximately 0.72 oz.

Amount of ice dispensed per second.

DCM-500BAH(-OS), DCM-500BWH(-OS) . . . . . . Approximately 1.2 oz.

4. Control Board Check Procedure

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.

a) Power Supply

1. Move the control switch to the "ICE" position. The "POWER" LED should come on.
If the "POWER" LED is off, check that the power supply is on, the power switch is
in the "ON" position, the door switch is engaged, and the control switch is in the
"ICE" position. Check the transformer 10.5V secondary circuit and fuse. If the 10.5V
secondary circuit (K4 pins 1 and 2) has proper voltage and the "POWER" LED is off,
the control board is bad and should be replaced.

If the secondary circuit does not have proper voltage, see "IV.C.1.[1] The icemaker will
not start (Fill Cycle)" for further details.

b) Ice Making Components

1. Conrm the reservoir is full of water. If no water is in the reservoir, make sure that the
control switch is not in the "DRAIN" position and that the unit is not in the 12 hour drain
cycle. Also check the water supply line, water shutoff valve, and water lters. In the ll
cycle, the "POWER" LED is the only LED lit on the control board. If no water is lling
the reservoir, check for 24V at connector K2 terminal 7 to neutral and connector K3
(DBU) to neutral. If there is 24V at connector K2 terminal 7 to neutral and no voltage at
K3 (DBU) to neutral, the control board is bad and should be replaced. See "IV.C.1.[1]
The icemaker will not start (Fill Cycle)" for further details.

2. When the reservoir is full, the "GM" LED comes on and the gear motor starts. If
the "GM" LED does not come on or the gear motor does not start, check that the
following safety circuits are closed: a) high pressure switch (DCM-500BAH and DCM­500BWH, connector K4 terminals 9 and 10, DCM-500BAH-OS and DCM-500BWH-OS,
connector K4 terminals 5 and 6), b) low water safety/bin control/ice making switch
circuit (connector K4 terminals 3 and 4). Next, check for 115/120V at connector K1
"COM" and K1 "NO" on the control board to neutral. If the "GM" LED is on and there is
voltage at K1 "COM" to neutral and no voltage at K1 "NO" to neutral, the control board
is bad and should be replaced. See wiring diagram "III.C.2. Ice Purge Cycle" for further
details.

18

3. 60 seconds after the "GM" LED comes on, the "COMP" LED comes on, and the
compressor and fan motor start. If the "COMP" LED does not come on 60 seconds
after the gear motor starts, check that the gear motor protect relay contacts (connector
K2 terminals 1 and 2) have closed. If the "COMP" LED is on and the compressor and
fan motor did not start, check for 115/120V at X2 (LBU) and X2 (BR) on the control
board to neutral. If the "COMP" LED is on and there is voltage at X2 (BR) to neutral
and no voltage at X2 (LBU) to neutral, the control board is bad and should be replaced.
See wiring diagram "III.C.3. Freeze Cycle" for further details.

c) Dispensing Components DCM-500BAH, DCM-500BWH

1. Ice Dispense "Continuous": Pressing the ice dispense switch closes terminals 6 and 5
at the K4 connector. The "DM" LED comes on and the dispensing motor energizes. If
the "DM" LED does not turn on, check continuity through the ice dispense switch and
the dispense mode switch. If the LED is on and the dispensing motor does not start,
check for 115/120V at connector K2 terminals 3 and 6 to a neutral. With voltage at
terminal 3 and not at terminal 6, the control board is bad and should be replaced.
Note: The agitating motor will operate .6 seconds every 12 seconds of accumulative

dispense time. See "III.D.1. Continuous Dispense."

2. Ice Dispense "Portion": Pressing the ice dispense switch closes terminals 6 and 7 at
the K4 connector. The "DM" LED comes on and the dispinsing motor energizes. If the
"DM" LED does not turn on, check continuity through the ice dispense switch and the
dispense mode switch. If the LED is on and the dispensing motor does not start, check
for 115V at connector K2 terminals 3 and 6 to a neutral. With voltage at terminal 3 and
not at terminal 6, the control board is bad and should be replaced.
Note: The agitating motor will operate .6 seconds every 12 seconds of accumulative

dispense time. See "III.D.2. Portion Dipsense."

d) Dispensing Components DCM-500BAH-OS, DCM-500BWH-OS

See "IV.C.5. Opti Serve (OS) Sensors."

19

E. Float Switch

Depending on local water conditions, scale may build up on the oat switch. Scale on the
switch can cause the oats to stick. In this case, the oat switch should be cleaned and
checked.
First, remove the switch from the water tank. Soak the switch assembly in ice machine
cleaner. While not necessary, the oats can be removed from the shaft during cleaning.
If you remove them, note that the blue oat is on top. The oats must be installed with
the magnets inside them towards the top of the switch. Installing the oats upside down
will affect the timing of the oat switch operation. Once clean, rinse and wipe the cleaner
off. Next, check the switch with an ohm meter. This oat switch has three wires (the
black wire is common) and two separate switches. Check the upper switch by ohming
out the black and red wires. When the oat is up, the switch should be closed. Check the
lower switch by ohming out the black and blue wires in the same manner. If either switch
fails, the assembly should be replaced.

Red (upper)

Black (common)

Blue (lower)

Magnet (towards top)

Upper Float (blue)

Spring Retainer Clip

Magnet (towards top)

Lower Float (white)

Plastic Retainer Clip

20

III. Technical Information

A. Water Circuit and Refrigeration Circuit

1. DCM-500BAH(-OS)

Water Supply

Inlet
Water
Val ve

Reservoir

Float Switch

Overow

Water Level

Evaporator

Gear Motor

Spout

Drier

Expansion
Val ve

To Drain

Drain
Val ve

Dispensing
Water Valve

Fan

Air-Cooled
Condenser

Access
Val ve

Refrigeration Circuit

Water Circuit

21

High
Pressure
Switch

Compressor

Access
Val ve