Hoshizaki American, Inc. CUBELET ICEMAKER/DISPENSER DCM-750BAH-OS User manual

Category
Ice cube makers
Type
User manual
Hoshizaki
“A Superior Degree
of Reliability”
www.hoshizaki.com
Models
DCM-750BAH
DCM-750BAH-OS
DCM-750BWH
DCM-750BWH-OS
Cubelet Icemaker / Dispenser
Hoshizaki America, Inc.
Number: 73166
Issued: 10-8-2008
SERVICE MANUAL
®
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.
68 Highway 74 South
Peachtree City, GA 3069
Attn: Hoshizaki Technical Support Department
Phone: -800-33-940 Technical Service
(770) 487-33
Fax: -800-843-056
(770) 487-3360
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.
3
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
. DCM-750BAH ..........................................................................................................
5
. DCM-750BAH-OS ................................................................................................... 6
3. DCM-750BWH ......................................................................................................... 7
4. DCM-750BWH-OS .................................................................................................. 8
II. General Information ........................................................................................................... 9
A. Construction .................................................................................................................. 9
B. Ice Making Unit ........................................................................................................... 
C. Sequence of Operation ............................................................................................... 
. Fill Cycle ................................................................................................................ 
. Ice Purge Cycle (60 seconds) ............................................................................... 
3. Freeze Cycle ......................................................................................................... 
4. Drain Cycle ............................................................................................................ 
5. Shutdown .............................................................................................................. 
D. Control Board ............................................................................................................. 4
. Control Board Layout ............................................................................................ 5
a) DCM-750BAH, DCM-750BWH ......................................................................... 5
b) DCM-750BAH-OS, DCM-750BWH-OS ............................................................ 6
. Features ................................................................................................................ 7
3. Controls and Adjustments .................................................................................... 8
4. Control Board Check Procedure ........................................................................... 8
E. Float Switch ................................................................................................................ 0
III. Technical Information ..................................................................................................... 
A. Water Circuit and Refrigeration Circuit ....................................................................... 
B. Wiring Diagrams ......................................................................................................... 3
. DCM-750BAH, DCM-750BWH ............................................................................. 3
. DCM-750BAH-OS, DCM-750BWH-OS ................................................................ 4
C. Sequence of Electrical Circuit – Ice Making ............................................................... 5
. Fill Cycle ............................................................................................................... 5
. Ice Purge Cycle .................................................................................................... 6
3. Freeze Cycle ........................................................................................................ 7
4.  Hour Drain Cycle / Drain Switch ....................................................................... 8
5. Shutdown .............................................................................................................. 9
6. Low Water Safety ................................................................................................. 30
7. High Pressure Switch ........................................................................................... 3
D. Sequence of Electrical Circuit – Dispensing .............................................................. 3
. Continuous Dispense ............................................................................................ 3
. Portion Dispense ................................................................................................... 33
4
E. Performance Data ....................................................................................................... 34
. DCM-750BAH(-OS) ............................................................................................... 34
. DCM-750BWH(-OS) ..............................................................................................
35
IV. Service Diagnosis .......................................................................................................... 36
A. Diagnostic Procedure ................................................................................................. 36
B. Ice Production Check .................................................................................................. 37
C. Diagnostic Charts ....................................................................................................... 38
. No Ice Production ..................................................................................................
38
. Low Ice Production ................................................................................................
4
3. Other ..................................................................................................................... 4
4. Dispensing ............................................................................................................. 43
5. Opti Serve (OS) Sensors ....................................................................................... 44
V. Removal and Replacement of Components ................................................................... 46
A. Service for Refrigerant Lines ...................................................................................... 46
. Refrigerant Recovery ............................................................................................
46
. 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
. Upper Bearing Wear Check ................................................................................. 5
. Removal and Replacement of Extruding Head .....................................................
5
3. Removal and Replacement of Auger .................................................................... 5
4. Removal and Replacement of Evaporator ............................................................ 5
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 ..................................................... 6
. Dispensing Auger and Agitator .............................................................................. 6
. Dispensing or Agitating Motor ............................................................................... 6
VI. Cleaning and Maintenance ............................................................................................ 63
A. Cleaning and Sanitizing Instructions ........................................................................... 63
. Water System ........................................................................................................
64
a) Cleaning Solution ............................................................................................... 64
b) Cleaning Procedure ............................................................................................ 64
c) Sanitizing Solution .............................................................................................. 65
d) Sanitizing Procedure - Following Cleaning Procedure ...................................... 65
. 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
5
I. Specications
A. Icemaker
1. DCM-750BAH
Note: We reserve the right to make changes in specications and design without prior
notice.
AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 13.2 RLA 60 LRA
GEAR MOTOR 120 V 3 FLA 1/4 HP
FAN MOTOR 120 V 0.85 FLA 1/15 HP
AGITATING MOTOR 120 V 1.8 FLA (Total) 110 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHER 120 V 0.6 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACIT
Y
20 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp.(°F) 50 70 90
lbs./day ( kg/day ) 70 * 803 (364) 770 (349) 726 (329)
Reference without *marks 80 684 (310) 645 (293) 608 (276)
90 573 (260) * 567 (257) 509 (231)
100 480 (218) 452 (205) * 423 (192)
SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Approx. 90%, Ice (90/70°F, Conductivity 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 95 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 1481 (6.3) 1449 (4.3)
POTABLE WATER 68 (12) 96 (12)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 34-1/16" x 28-1/2" x 48-1/16" (865 x 723 x 1221 mm)
EXTERIOR FINISH Stainless Steel; Galvanized Steel (Rear)
WEIGHT Net 375 lbs. ( 170 kg ), Shipping 405 lbs. ( 184 kg )
CONNECTIONS - ELECTRIC Permanent Connection
- WATER SUPPLY Inlet 1/2" FPT
- DRAIN Drain Pan 3/4" FPT
Bin Drain 3/4" 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 N/A
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS55C2E-CAA-219
CONDENSER Air-cooled, Fin and tube type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R-404A, 1 lb. 7.1 oz. (660 g)
DESIGN PRESSURE High 460 PSIG, Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-off Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Manual reset Circuit Breaker
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Time
r
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
ENG F-013.0.1196
6
2. DCM-750BAH-OS
Note: We reserve the right to make changes in specications and design without prior
notice.
AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 13.2 RLA 60 LRA
GEAR MOTOR 120 V 3 FLA 1/4 HP
FAN MOTOR 120 V 0.85 FLA 1/15 HP
AGITATING MOTOR 120 V 1.8 FLA (Total) 110 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHER 120 V 0.6 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACIT
Y
20 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp.(°F) 50 70 90
lbs./day ( kg/day ) 70 * 803 (364) 770 (349) 726 (329)
Reference without *marks 80 684 (310) 645 (293) 608 (276)
90 573 (260) * 567 (257) 509 (231)
100 480 (218) 452 (205) * 423 (192)
SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Approx. 90%, Ice (90/70°F, Conductivity 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 95 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 1481 (6.3) 1449 (4.3)
POTABLE WATER 68 (12) 96 (12)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 34-1/16" x 28-1/2" x 48-1/16" (865 x 723 x 1221 mm)
EXTERIOR FINISH Stainless Steel; Galvanized Steel (Rear)
WEIGHT Net 375 lbs. ( 170 kg ), Shipping 405 lbs. ( 184 kg )
CONNECTIONS - ELECTRIC Permanent Connection
- WATER SUPPLY Inlet 1/2" FPT
- DRAIN Drain Pan 3/4" FPT
Bin Drain 3/4" 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 N/A
DISPENSER CONTROL SYSTEM Photoelectric Sensor (Infrared)
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS55C2E-CAA-219
CONDENSER Air-cooled, Fin and tube type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R-404A, 1 lb. 7.1 oz. (660 g)
DESIGN PRESSURE High 460 PSIG, Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-off Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Manual reset Circuit Breaker
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Time
r
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
ENG F-013.0.1196
7
Note: We reserve the right to make changes in specications and design without prior
notice.
3. DCM-750BWH
AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 13.2 RLA 60 LRA
GEAR MOTOR 120 V 3 FLA 1/4 HP
AGITATING MOTOR 120 V 1.8 FLA (Total) 110 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHER 120 V 0.6 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACIT
Y
20 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp.(°F) 50 70 90
lbs./day ( kg/day ) 70 * 744 (337) 719 (326) 708 (321)
Reference without *marks 80 696 (316) 684 (310) 673 (305)
90 662 (300) * 654 (297) 640 (291)
100 630 (286) 620 (281) * 573 (260)
SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Approx. 90%, Ice (90/70°F, Conductivity 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 95 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 1383 (5.1) 1410 (4.5)
POTABLE WATER 89 (12) 78 (12)
WATER-COOLED CONDENSER 606 (81.4) 325 (49.7)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 34-1/16" x 28-1/2" x 48-1/16" (865 x 723 x 1221 mm)
EXTERIOR FINISH Stainless Steel; Galvanized Steel (Rear)
WEIGHT Net 375 lbs. ( 170 kg ), Shipping 405 lbs. ( 184 kg )
CONNECTIONS - ELECTRIC Permanent Connection
- WATER SUPPLY Inlet 1/2" FPT Condenser Inlet 1/2" FPT
- DRAIN Drain Pan 3/4" FPT Condenser Outlet 1/2" FPT
Bin Drain 3/4" 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 Water Regulating Valve
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS55C2E-CAA-219
CONDENSER Air-cooled, Fin and tube type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R-404A, 1 lb. 2.7 oz. (530 g)
DESIGN PRESSURE High 460 PSIG, Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-off Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Manual reset Circuit Breaker
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Time
r
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
ENG F-013.0.1196
8
4. DCM-750BWH-OS
Note: We reserve the right to make changes in specications and design without prior
notice.
AC SUPPLY VOLTAGE 115/60/1
COMPRESSOR 120 V 10 RLA 60 LRA
GEAR MOTOR 120 V 3 FLA 1/4 HP
AGITATING MOTOR 120 V 1.8 FLA (Total) 110 W
DISPENSING MOTOR 120 V 0.9 FLA 55 W
OTHER 120 V 0.6 A
MAXIMUM FUSE SIZE 20 A
MAX. HACR BREAKER (USA ONLY) 20 A
MAX. CIRC. BREAKER (CANADA ONLY) 20 A
MINIMUM CIRCUIT AMPACIT
Y
20 A
APPROXIMATE ICE PRODUCTION Ambient
PER 24 HR. Temp.(°F)
lbs./day ( kg/day ) 70 * 744 337
719 326 708 321
Reference without *marks 80 696 316 684 310 673 305
90 662 300 * 654 297 640 291
100 630 286 620 281 * 573 260
SHAPE OF ICE Cubelet (Compressed Flake Ice)
ICE QUALITY Approx. 88%, Ice (90/70°F, Conductivity 200 µs/cm)
APPROXIMATE STORAGE CAPACITY 95 lbs.
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 1383 (5.1) 1410 (4.5)
POTABLE WATER 89 (12) 78 (12)
WATER - COOLED CONDENSER 606 (81.4) 325 (49.7)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH) 34-1/16" x 28-1/2" x 48-1/16" (865 x 723 x 1221 mm)
EXTERIOR FINISH Stainless Steel; Galvanized Steel (Rear)
WEIGHT Net 375 lbs. ( 170 kg ), Shipping 405 lbs. ( 184 kg )
CONNECTIONS - ELECTRIC Permanent Connection
- WATER SUPPLY Inlet 1/2" FPT Condenser Inlet 1/2" FPT
- DRAIN Drain Pan 3/4" FPT Condenser Outlet 1/2" FPT
Bin Drain 3/4" 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 Water Regulating Valve
DISPENSER CONTROL SYSTEM Photoelectric Sensor (Infrared)
BIN CONTROL SYSTEM Mechanical Bin Control ( Proximity Sw. )
COMPRESSOR Hermetic, Model RS55C1E-PAA
CONDENSER Water-cooled, Double tube type
EVAPORATOR Copper Tube on Cylinder
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R-404A, (530 g)
DESIGN PRESSURE High 460 PSIG, Low 290 PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-off Relay
COMPRESSOR PROTECTION Auto-reset Overload Protector
GEAR MOTOR PROTECTION Manual reset Circuit Breaker
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch and Time
r
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
WATER TEMP. (°F)
1 lb. 2.7 oz.
50 70 90
ENG F-013.0.1196
9
II. General Information
A. Construction
1. DCM-750BAH(-OS)
Storage Bin
Inlet Water Valve
Reservoir
Control Box
Air-Cooled Condenser
Spout Cover
Evaporator Assembly
Compressor
Dispensing Motor
Agitator (L)
Dispensing Auger
Dispensing Water Valve
Spout B
Float Switch
Dispense Mode
Switch
Control Switch
Shutter Assembly
Power Switch
Drier
Spout A
Drain Water Valve
Expansion Valve
Door Switch
Agitator (R)
Agitating Motor (L)
Agitating Motor (R)
Gear Motor
Bin Control Switch
0
2. DCM-750BWH(-OS)
Storage Bin
Inlet Water Valve
Reservoir
Control Box
Water-Cooled Condenser
Spout Cover
Evaporator Assembly
Compressor
Dispensing Motor
Agitator (L)
Dispensing Auger
Dispensing Water Valve
Spout B
Float Switch
Dispense Mode
Switch
Control Switch
Shutter Assembly
Power Switch
Drier
Spout A
Drain Water Valve
Door Switch
Expansion Valve
Agitator (R)
Agitating Motor (R)
Agitating Motor (L)
Bin Control Switch
Gear Motor

B. Ice Making Unit
1. DCM-750BAH(-OS)
Cubelet Cutter
Allen Head Cap Screw
Gear Motor
O-Ring
Mechanical Seal
Extruding Head
and Upper Bearing
Hex Head Bolt
with Washer
Auger
Evaporator
Housing and
Lower Bearing
Cylinder
Insulation
Allen Head Cap Screw
with Washer
Washer
Extruding Head Heater
Capacitor

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, GMPR, HCR, and HTR 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 WCR and WV as needed
to continue the icemaking process. This continues until BC shuts the icemaker down or
power is turned off to the icemaker.
4. Drain Cycle
 hour DT activates, "FLUSH" LED is on after 50 second shutdown sequence. Comp
and FMS de-energize 90 seconds after the  hour DT activates, GM, GMPR, HCR,
and HTR de-energize 60 seconds later. DV then energizes and remains energized for
0 minutes.
5. Shutdown
BC is activated and a 50 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, GMPR, HCR, and HTR de-energize.
Legend: AM–agitating motors; BC–bin control; Comp–compressor; DT–drain timer;
FMS–self-contained fan motor; GM–gear motor; GMPR–gear motor
protect relay; HCR–heater control relay; HTR–extruding head heater;
LF/S–lower oat switch; UF/S–upper oat switch; WCR–water control relay;
WV–inlet water valve
3
Legend:
BC - bin control
Comp - compressor
DC - drain cycle
DT - drain timer
DV - drain valve
FMS - self-contained fan motor
FT - ll timer (low water safety)
GM - gear motor
GMPR - gear motor protect relay
HCR - heater control relay
HTR - extruding head heater
LF/S - lower oat switch
UF/S - upper oat switch
WCR - water control relay
WV - inlet water valve
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 50 second shutdown sequence
terminates (. Shutdown & Restart).
Note: To bypass the 50 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.
UF/S open
LF/S open (WV on)
WCR off
FT started (90 sec.)
WV on
Comp continues
FMS continues
GM continues
GMPR continues
HCR continues
HTR continues
DCM-750BAH(-OS), DCM-750BWH(-OS) Sequence Flow Chart and Component Operation
1. Startup
2. Ice Purge Cycle
WV on
LF/S closed
UF/S closed (WV off)
WCR on
WV off
GM on
GMPR on
HCR on
HTR on
Comp on
FMS on
WCR continues
GM continues
GMPR continues
HCR continues
HTR continues
Power switch "ON"
Control switch in "ICE"
1. Fill Cycle
3. Freeze Cycle
Rell
(90 seconds)
LF/S closed
UF/S closed (WV off)
WCR on
FT off (90 sec.)
WV off
Comp continues
FMS continues
GM continues
GMPR continues
HCR continues
HTR continues
Low Water Safety
UF/S open
FT exceeded
Comp continues
FMS continues
GM continues
GMPR continues
HCR continues
HTR continues
WV continues
Comp off
FMS off
WV continues
GM continues
GMPR continues
HCR continues
HTR continues
GM off
GMPR off
HCR off
HTR off
WV continues until
UF/S closes
90 seconds
60 seconds
If rell > 90 sec. FT, 50 second
shutdown sequence begins
60 seconds
150 sec. Shutdown Sequence
UF/S open
60 seconds
2. Shutdown & Restart
90 seconds
1. Bin Full
Comp off
FMS off
GM continues
GMPR continues
HCR continues
HTR continues
GM off
GMPR off
HCR off
HTR off
DV on (DC only)
3. Icemaker is Off
BC open or DC starts
Comp continues
FMS continues
GM continues
GMPR continues
HCR continues
HTR continues
2. Ice Purge Cycle
4. Ice Level Lowered
See "1. Fill Cycle" above
150 seconds
BC closed
or
20 Min. DT off (DC only)
DV off (DC only)
12 hour DT reset (DC only)
4. 12 Hour Drain Cycle
DV opens for 0 minutes every  hours
See "3.  Hour Drain Cycle" below.
3. 12 Hour Drain Cycle
Shutdown & Restart
1. Drain Cycle initiates
2. Ice Purge Cycle
3. Drain Cycle
4. 12 hour DC - Restart
See "1. Fill Cycle" above
DV on for 20 minutes
4
D. Control Board
• A Hoshizaki exclusive solid-state control board is employed in DCM-750BAH,
DCM-750BAH-OS, DCM-750BWH, and DCM-750BWH-OS Cubelet Icemaker /
Dispensers.
• All models are pretested and factory-adjusted.
CAUTION
. Fragile, handle very carefully.
. 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.
5
Microprocessor (board revision level
indicated by last  digits on label)
"POWER" LED
(lights when
power is supplied
to the board)
"FLUSH" LED
(X5 Relay)
Drain Valve
"COMP" LED
(X Relay)
Compressor,
Fan Motor
0.5V
Transformer
"GM" LED
(X Relay)
Gear Motor
"DM" LED
(X4 Relay)
Shutter Solenoid,
Dispensing Auger
Motor
4V In
4V Supply Out
5V In
Gear Motor
Protect Relay
Circuit
Portion Control
Timer
"AM" LED
(X3 Relay)
Agitating Motor
Drain Valve
4V Out
Dispensing Motor
5V Out
Agitating Motors
5V Out
5V In
Gear Motor
5V Out
5V In
Counter Reset Button (not
used in this application)
Control Board
Part Number A59-0
1. Control Board Layout
a) DCM-750BAH, DCM-750BWH
Dispensing
Components
See "III.
B. Wiring
Diagrams"
for details.
Bin Control,
Control
Switch,
Low Water
Safety
High
Pressure
Switch
Flush Switch
Must be left in the "P" position,
otherwise the internal drain
timer will not operate.
6
Dispensing Components
See "III.B. Wiring Diagrams"
for details.
Bin Control,
Control Switch,
Low Water Safety
Microprocessor (board revision level
indicated by last  digits on label)
"POWER" LED
(lights when
power is supplied
to the board)
"FLUSH" LED
(X6 Relay)
Drain Valve
"COMP" LED
(X Relay)
Compressor,
Fan Motor
0.5V
Transformer
High
Pressure
Switch
"GM" LED
(X Relay)
Gear Motor
"WTR" LED
(X5 Relay)
Dispensing
Water Valve
"ICE" LED
(X4 Relay)
Shutter Solenoid,
Dispensing Auger
Motor
4V In
4V Supply Out
5V In
Gear Motor
Protect Relay
Circuit
Portion Control
Timer
"AM" LED
(X3 Relay)
Agitating Motor
Drain Valve
4V Out
Dispensing Motor
5V Out
Dispensing
Water Valve
4V Out
4V In
Agitating Motors
5V Out
5V In
Gear Motor
5V Out
5V In
Counter Reset Button (not
used in this application)
Control Board
Part Number A649-0
Flush Switch
Must be left in the "P" position,
otherwise the internal drain
timer will not operate.
b) DCM-750BAH-OS, DCM-750BWH-OS
7
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
Energized
Components
Time LEDs are
On
Frequency LEDs are
On
Fill POWER only WV N/A As Needed
Ice Purge (X)
GM GM, HTR 60 seconds N/A
Freeze (X, X)
GM, COMP
GM, HTR,
Comp, FMS
N/A N/A
Drain Valve (X6) FLUSH DV 0 Minutes Every  Hours
Dispensing
Relay LED
Energized
Component
Time LEDs are
On
Frequency LEDs are
On
Ice Dispense (X4)
Push Button
DM
IDM
60 seconds
maximum
N/A
Opti Serv
ICE
Agitating Motors (X3) AM AM .6 seconds
Every  seconds of
accumulative dispense
time
Water Dispense (X5)
(Opti Serv Only)
WTR WTR N/A N/A
Legend: AM–agitating motors, Comp–compressor; DV–drain valve; FMS–self-contained
fan motor; GM–gear motor; HTR–extruding head heater; IDM–ice dispensing
motor, shutter solenoid; WTR–dispensing water valve; WV–inlet water valve
8
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-750BAH(-OS), DCM-750BWH(-OS). . . . . . .Approximately 0.7 oz.
Amount of ice dispensed per second.
DCM-750BAH(-OS), DCM-750BWH(-OS) . . . . . . Approximately . 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
. 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 0.5V secondary circuit and fuse. If the 0.5V
secondary circuit (K4 pins  and ) 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..[] The icemaker will
not start (Fill Cycle)" for further details.
b) Ice Making Components
. 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  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 4V at connector K terminal 7 to neutral and connector K3
(DBU) to neutral. If there is 4V at connector K terminal 7 to neutral and no voltage at
K3 (DBU) to neutral, the control board is bad and should be replaced. See "IV.C..[]
The icemaker will not start (Fill Cycle)" for further details.
. 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-750BAH and DCM-750BWH,
connector K4 terminals 9 and 0, DCM-750BAH-OS and DCM-750BWH-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 5/0V at connector K "COM"
and K "NO" on the control board to neutral. If the "GM" LED is on and there is voltage
at K "COM" to neutral and no voltage at K "NO" to neutral, the control board is
bad and should be replaced. See wiring diagram "III.C.. Ice Purge Cycle" for further
details.
9
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
K terminals  and ) have closed. If the "COMP" LED is on and the compressor and
fan motor did not start, check for 5/0V at X (LBU) and X (BR) on the control
board to neutral. If the "COMP" LED is on and there is voltage at X (BR) to neutral
and no voltage at X (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-750BAH, DCM-750BWH
. 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 5/0V at connector K 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  seconds of accumulative
dispense time. See "III.D.. Continuous Dispense."
. 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 5V at connector K 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  seconds of accumulative
dispense time. See "III.D.. Portion Dipsense."
d) Dispensing Components DCM-750BAH-OS, DCM-750BWH-OS
See "IV.C.5. Opti Serve (OS) Sensors."
0
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)
Upper Float (blue)
Magnet (towards top)
Magnet (towards top)
Lower Float (white)
Plastic Retainer Clip
Spring Retainer Clip
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Hoshizaki American, Inc. CUBELET ICEMAKER/DISPENSER DCM-750BAH-OS User manual

Category
Ice cube makers
Type
User manual

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