Hoshizaki American, Inc. KMD-850MAH Service Manual

Hoshizaki America, Inc.

Hoshizaki

Modular Crescent Cuber

Models KMD-850MAH

“A Superior Degree

of Reliability”

www.hoshizaki.com

KMD-850MWH KMD-850MRH

SERVICE MANUAL

™

Number: 73163 Issued: 9-3-2008

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 3069

Attn: Hoshizaki Technical Support Department

Phone: 1-800-33-1940 Technical Service (770) 487-331 Fax: 1-800-843-1056 (770) 487-3360 E-mail: techsupport@hoshizaki.com

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.



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 ..................................................................................................................... 6

A. Icemaker ....................................................................................................................... 6

1. KMD-850MAH (air-cooled) ...................................................................................... 6

. KMD-850MWH (water-cooled) ................................................................................

3. KMD-850MRH (remote air-cooled) .......................................................................... 8

B. Condenser Unit ............................................................................................................. 9

1. URC-9F ................................................................................................................... 9

II. General Information ......................................................................................................... 11

A. Construction ................................................................................................................ 11

1. KMD-850MAH (air-cooled) .................................................................................... 11

. KMD-850MWH (water-cooled) .............................................................................. 1

3. KMD-850MRH (remote air-cooled) ........................................................................ 13

B. Sequence of Operation ............................................................................................... 14

1. One Minute Fill Cycle ............................................................................................ 14

. Initial Harvest Cycle .............................................................................................. 14

3. Freeze Cycle ........................................................................................................ 14

4. Pump-Out Cycle ................................................................................................... 14

5. Normal Harvest Cycle .......................................................................................... 15

C. Control Board ............................................................................................................. 17

1. Control Board Layout ............................................................................................ 18

. Features ................................................................................................................ 19

a) Maximum Water Supply Period – 6 minutes ...................................................... 19

b) Harvest Backup Timer and Freeze Timer .......................................................... 19

c) High Temperature Safety ................................................................................... 19

d) Low Water Safety ............................................................................................... 19

e) High Voltage and Low Voltage Cut-outs ............................................................ 19

f) LED Lights and Audible Alarm Safeties .............................................................. 0

3. Controls and Adjustments ..................................................................................... 1

a) Default Dip Switch Settings ................................................................................ 1

b) Harvest Timer (S4 dip switch 1 & ) ................................................................... 1

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

d) Pump-Out Frequency Control (S4 dip switch 5 & 6) .......................................... 

e) S4 Dip Switch 7 & 8 ........................................................................................... 3

f) Freeze Timer (S4 dip switch 9 & 10) ................................................................... 3

g) Float Switch Control (S5 dip switch 1 through 5) ............................................... 3

4. Control Board Check Procedure ........................................................................... 3

5. Control Board Replacement ................................................................................ 4

D. Harvest Control – Thermistor...................................................................................... 4

1. Thermistor Check Procedure ................................................................................ 4

E. Float Switch ................................................................................................................ 4

1. Float Switch Check Procedure .............................................................................. 4

. Float Switch Cleaning ............................................................................................ 6

F. Bin Control .................................................................................................................. 7

1. Explanation of Operation ....................................................................................... 7

. Bin Control Check Procedure ................................................................................ 7

III. Technical Information ..................................................................................................... 8

A. Water Circuit and Refrigeration Circuit ....................................................................... 8

1. KMD-850MAH (air-cooled) .................................................................................... 8

. KMD-850MWH (water-cooled) .............................................................................. 9

3. KMD-850MRH (remote air-cooled) ........................................................................ 30

B. Wiring Diagrams ......................................................................................................... 31

1. KMD-850MAH and KMD-850MWH ....................................................................... 31

. KMD-850MRH ....................................................................................................... 3

C. Performance Data ...................................................................................................... 33

1. KMD-850MAH (air-cooled) .................................................................................... 33

. KMD-850MWH (water-cooled) .............................................................................. 34

3. KMD-850MRH (remote air-cooled) ........................................................................ 35

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

A. 10-Minute Diagnostic Procedure ............................................................................... 36

B. Diagnostic Charts ....................................................................................................... 37

1. No Ice Production .................................................................................................. 37

. Evaporator is Frozen Up ....................................................................................... 41

3. Low Ice Production ................................................................................................ 4

4. Abnormal Ice ......................................................................................................... 4

5. Other ..................................................................................................................... 43

V. Removal and Replacement of Components ................................................................... 44

A. Service for Refrigerant Lines ...................................................................................... 44

1. Refrigerant Recovery ............................................................................................ 44

. Brazing .................................................................................................................. 44

3. Evacuation and Recharge (R-404A) ..................................................................... 45

B. Removal and Replacement of Compressor ................................................................ 46

C. Removal and Replacement of Expansion Valve......................................................... 47

D. Removal and Replacement of Hot Gas Valve or Liquid Line Valve ........................... 48

E. Removal and Replacement of Evaporator .................................................................. 49

F. Removal and Replacement of Water Regulating Valve - Water-Cooled Model Only . 49

G. Adjustment of Water Regulating Valve - Water-Cooled Model Only .......................... 50

H. Removal and Replacement of Headmaster (Condensing Pressure Regulator - C.P.R.)

- Remote Air-Cooled Model Only .............................................................................. 51

I. Removal and Replacement of Thermistor .................................................................... 5

J. Removal and Replacement of Fan Motor .................................................................... 53

K. Removal and Replacement of Inlet Water Valve or Drain Valve ................................ 53

L. Removal and Replacement of Pump Motor ................................................................ 54

M. Removal and Replacement of Bin Control ................................................................. 55

VI. Cleaning and Maintenance ............................................................................................ 56

A. Cleaning and Sanitizing Instructions ........................................................................... 56

1. Cleaning Procedure ............................................................................................... 57

. Sanitizing Procedure - Following Cleaning Procedure ..........................................

B. Maintenance ............................................................................................................... 59

C. Preparing the Icemaker for Long Storage .................................................................. 60

I. Specications

AC SUPPLY VOLTAGE 208-230/60/1 (3 wire with netrual for 115V) AMPERAGE 9.8 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR. Temp.(°F) 50 70 90 lbs./day ( kg/day ) 70 *786 (357) 743 (337) 685 (311) Reference without *marks 80 753 (342) 686 (311) 629 (285)

90 743 (337) *639 (290) 580 (263)

100 732 (332) 625 (284) 526 (239) SHAPE OF ICE Crescent Cube ICE PRODUCTION PER CYCLE 11.8 lbs. (5.4 kg) 624pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 1570(5.9) 1510(4.6) WATER gal./24HR (gal./100 lbs.) 125(19.5) 291(37.0) CEC/CEE TIER LEVEL 1 ENERGY STAR NO EXTERIOR DIMENSIONS (WxDxH) 30" x 24-5/8" x 28" (762 x 625 x 713 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 217 lbs. (98 kg), Shipping 249 lbs. (113 kg) CONNECTIONS - ELECTRIC Permanent - Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

5/8" OD Tube CUBE CONTROL SYSTEM Float Switch HARVESTING CONTROL SYSTEM Hot Gas and Water, Thermistor and Timer ICE MAKING WATER CONTROL Timer Controlled. Overflow Pipe COOLING WATER CONTROL N/A BIN CONTROL SYSTEM Mechanical Lever Switch and Timer COMPRESSOR Hermetic, Model CS08KQE-PFV-255 CONDENSER Air-Cooled , Fin and tube type EVAPORATOR Vertical type, Stainless Steel and Copper REFRIGERANT CONTROL Thermostatic Expansion Valve REFRIGERANT CHARGE R404A, 2 lb. 8.2 oz. (1140g) DESIGN PRESSURE High 467PSIG, Low 230PSIG P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out ( Internal ) COMPRESSOR PROTECTION Auto-reset Overload Protector ( Internal ) REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch LOW WATER PROTECTION Float Switch ACCESSORIES -SUPPLIED N/A

-REQUIRED Ice Dispenser or Ice Storage Bin OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 V

AMBIENT TEMP. 45 -100° F WATER SUPPLY TEMP. 45 - 90° F

WATER SUPPLY PRESSURE 10 - 113 PSIG

A. Icemaker

1. KMD-850MAH (air-cooled)

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

notice.

AC SUPPLY VOLTAGE 208-230/60/1 (3 wire with netrual for 115V) AMPERAGE 8.3A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR. Temp.(°F) 50 70 90 lbs./day ( kg/day ) 70 *836 (379) 830 (376) 786 (357) Reference without *marks 80 831 (377) 822 (373) 759 (344)

90 830 (376) *815 (370) 759 (344)

100 809 (367) 802 (364) 708 (321) SHAPE OF ICE Crescent Cube ICE PRODUCTION PER CYCLE 12.1 lbs. (5.5 kg) 624pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 1390(4.1) 1390(4.0) WATER gal./24HR (gal./100 lbs.) 165(20.2) 298(35.7) WATER COOLED CONDENSER 1035(127) 565(68)

gal./24HR (gal./100 lbs.) CEC/CEE TIER LEVEL 2 ENERGY STAR N/A EXTERIOR DIMENSIONS (WxDxH) 30" x 24-5/8" x 28" (762 x 625 x 713 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 217 lbs. (98 kg), Shipping 249 lbs. (113 kg) CONNECTIONS - ELECTRIC Permanent - Connection

- WATER SUPPLY Inlet 1/2" FPT Cond. Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT Cond. Outlet 3/8" FPT

5/8" OD Tube CUBE CONTROL SYSTEM Float Switch HARVESTING CONTROL SYSTEM Hot Gas and Water, Thermistor and Timer ICE MAKING WATER CONTROL Timer Controlled. Overflow Pipe COOLING WATER CONTROL Pressure Regulator BIN CONTROL SYSTEM Mechanical Lever Switch and Timer COMPRESSOR Hermetic, Model CS08KQE-PFV-255 CONDENSER Water-cooled, Tube in tube type EVAPORATOR Vertical type, Stainless Steel and Copper REFRIGERANT CONTROL Thermostatic Expansion Valve REFRIGERANT CHARGE R404A, 1 lb. 12.6 oz. (810g) DESIGN PRESSURE High 427PSIG, Low 230PSIG P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out ( Internal ) COMPRESSOR PROTECTION Auto-reset Overload Protector ( Internal ) REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch LOW WATER PROTECTION Float Switch ACCESSORIES -SUPPLIED N/A

-REQUIRED Ice Dispenser or Ice Storage Bin OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 V

AMBIENT TEMP. 45 -100° F WATER SUPPLY TEMP. 45 - 90° F WATER SUPPLY PRESSURE 10 - 113 PSIG

2. KMD-850MWH (water-cooled)

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

notice.

3. KMD-850MRH (remote air-cooled)

AC SUPPLY VOLTAGE 208-230/60/1 (3 wire with netrual for 115V) AMPERAGE 9.8A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR. Temp.(°F) 50 70 90 lbs./day ( kg/day ) 70 *833 (378) 793 (360) 738 (335) Reference without *marks 80 803 (364) 741 (336) 686 (311)

90 793 (360) *698 (317) 641 (291)

100 782 (355) 685 (311) 589 (267) SHAPE OF ICE Crescent Cube ICE PRODUCTION PER CYCLE 11.6 lbs. (5.3 kg) 624pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 1570(5.4) 1490(4.3) WATER gal./24HR (gal./100 lbs.) 136(19.5) 280(33.6) CEC/CEE TIER LEVEL 2 ENERGY STAR YES EXTERIOR DIMENSIONS (WxDxH) 30" x 24-5/8" x 28" (762 x 625 x 713 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 203 lbs. (92 kg), Shipping 235 lbs. (107 kg) CONNECTIONS - ELECTRIC Permanent - Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

Condensing Pressure Regulator on URC-9F

REFRIGERANT CHARGE R404A, 9 lbs. 4.2 oz. (4200g)

(Icemaker 5 lbs. 5.4 oz. Cond. Unit 3 lbs. 14.8 oz.) DESIGN PRESSURE High 467PSIG, Low 230PSIG P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out ( Internal ) COMPRESSOR PROTECTION Auto-reset Overload Protector ( Internal ) REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch LOW WATER PROTECTION Float Switch ACCESSORIES -SUPPLIED N/A

-REQUIRED Ice Dispenser or Ice Storage Bin, Remote Condenser Unit OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 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.

B. Condenser Unit

1. URC-9F

Unit: mm [inches]

AC SUPPLY VOLTAGE 115/60/1 (Connection to Icemaker)

FAN MOTOR 115 V Total 1.3FLA 65W

EXTERIOR DIMENSIONS (WxDxH) 32-3/16" x 15-11/16" x 21-15/16" (817 x 398 x 558 mm)

DIMENSIONS INCLUDING LEGS (WxDxH) 34-5/16" x 18-1/8" x 36-15/16" (871 x 460 x 938 mm)

EXTERIOR FINISH Galvanized Steel

WEIGHT Net 81 lbs. ( 37 kg ) Shipping 92 lbs. ( 42 kg )

CONNECTIONS - ELECTRIC Permanent - Connection

- REFRIGERANT Discharge Line 1-1/16"-12 UNF Fitting (#10 AEROQUIP)

Liquid Line 5/8"-18 UNF Fitting (#6 AEROQUIP)

CONDENSER Air-cooled, Fin and tube type

FAN MOTOR PROTECTION Thermal Protection

REFRIGERANT CONTROL Condensing Pressure Regulator

REFRIGERANT CHARGE R-404A 3 lbs. 14.8 oz. (1780g)

DESIGN PRESSURE High 467 PSIG

OPERATING CONDITIONS VOLTAGE RANGE 104 ~ 127 V

AMBIENT TEMP. -20 ~ 122 °F

ACCESSORIES -SUPPLIED Leg 2 pcs

Hex. Head Bolt w/Washer 8 x 16 8 pcs

Hex. Nut 8 8 pcs

Specications

MODEL: URC-9F

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

notice.

II. General Information

A. Construction

1. KMD-850MAH (air-cooled)

Spray Tubes

Inlet Water Valve

Water Supply Inlet

Hot Gas Valve

Junction Box

Condenser

Control Box

Float Switch

Drain Valve

Expansion Valves

Cleaning Valve

Condenser Fan Motor

Control Switch

Drier

Compressor

Water Pump

Bin Control

2. KMD-850MWH (water-cooled)

Spray Tubes

Inlet Water Valve

Water Supply Inlet

Hot Gas Valve

Junction Box

Condenser

Control Box

Water Regulator

Float Switch

Drain Valve

Control Switch

Drier

Compressor

Water Pump

Cleaning Valve

Expansion Valves

Bin Control

1

3. KMD-850MRH (remote air-cooled)

Spray Tubes

Inlet Water Valve

Water Supply Inlet

Hot Gas Valve

Junction Boxes

Control Box

Receiver Tank

Control Switch

Float Switch

Drain Valve

Water Pump

Drier

Liquid Line Valve

Compressor

Cleaning Valve

Expansion Valves

Bin Control

B. Sequence of Operation

The steps in the sequence are as outlined below. When power is supplied, the red "POWER OK" LED and the green "BC CLOSED" LED on the control board come on (If the yellow "BC OPEN" LED is on, the unit will not start. In this case clear ice away from the bin control actuator). A 5-second delay occurs at startup. Note that the order of the green sequence LEDs from the outer edge of the board is 1, 4, 3, .

1. One Minute Fill Cycle

LED 4 is on. WV opens and the ll period begins. After 1 minute, the board checks for a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV will remain energized through additional 1 minute cycles until water enters the sump and F/S closes. This serves as a low water safety to protect the water pump.

2. Initial Harvest Cycle

LEDs 1, 4, and  are on. WV remains open, Comp, FMR, HGV energize. The control board monitors the warming of the evaporator via the thermistor located on the suction line. When the thermistor reaches 48°F (9°C), the control board reads a 3.9 kΩ signal from the thermistor and turns harvest termination over to the adjustable harvest timer which is factory set for normal conditions. The timer has settings of 60, 90, 10, and 180 seconds (S4 dip switch 1 & ). For details, see "II.C.3.b) Harvest Timer." When the harvest timer completes its countdown, the harvest cycle is complete and the freeze cycle starts. The minimum total time allowed by the board for a complete harvest cycle is  minutes. WV is open during harvest for a maximum of 6 minutes or the length of harvest minus 50 seconds, whichever is shorter. LED 4 goes off when WV closes. PM energizes and runs for the last 50 seconds of harvest. LED 3 comes on when PM energizes. At the end of harvest, the control board checks the position of F/S and proceeds to the freeze cycle if it is closed or calls for a 1-minute ll if it is open.

3. Freeze Cycle

LED 1 is on. Comp, FMR, and PM continue to run, FMS energizes, LLV opens, HGV closes and the freeze cycle starts. For the rst 5 minutes the control board will not accept a signal from F/S. This 5 minute minimum freeze acts as a short cycle protection. At the end of 5 minutes, F/S assumes control. As ice builds on the evaporator the water level in the sump lowers. The freeze continues until F/S opens and terminates ice production.

4. Pump-Out Cycle

LEDs 1, 4, 3, and  are on. With S4 dip switch 5 and 6 in the factory default position, the 1st pump out occurs after the 11th freeze cycle and every 10th cycle thereafter. Comp and FMR continue to run, DV and WV open, HGV opens, LLV closes, and FMS deenergizes. PM stops for  seconds. SR energizes, restarting PM and taking water from the sump and forcing it to go through DV and down the drain. At the same time, water ows through the vent tube to power ush the F/S. After 10 seconds, the pump out is complete. The pump-out frequency control is factory-adjusted to drain the water tank every 10 cycles, and no adjustment is required. However, where water quality is bad and the icemaker needs a pump out more often, the pump-out frequency can be adjusted. The pump-out frequency control can be set to have a pump out occur every cycle, or every , 5, or 10 cycles (S4 dip switch 5 & 6). For details, see "II.C.3.d) Pump-Out Frequency Control."

5. Normal Harvest Cycle

LEDs 1, 4, and  are on. Comp, FMR, and HGV remain energized and WV opens. PM stops. As the evaporator warms, the thermistor reaches 48°F (9°C). The control board then receives the thermistor's 3.9 kΩ signal and starts the harvest timer. When the harvest timer completes its countdown, the harvest cycle is complete. The minimum total time allowed by the board for a complete harvest cycle is  minutes. WV is energized during harvest for a maximum of 6 minutes or the length of harvest minus 50 seconds, whichever is shorter. LED 4 goes off when WV closes. PM energizes and runs for the last 50 seconds of harvest. LED 3 comes on when PM energizes. At the end of harvest, the control board checks the position of F/S and proceeds to the freeze cycle if it is closed or calls for a 1-minute ll if it is open. The unit continues to cycle through freeze and harvest cycles until the bin control activates (opens) and shuts the unit down.

Note: To prevent incomplete batches of ice from forming on the evaporator, the control

board will only shut down the machine within the rst 5 minutes of the freeze cycle. If ice pushes the bin control actuator in (open) after the rst ve minutes of the freeze cycle, the control board will allow the machine to complete the freeze cycle and the following harvest cycle before shutting down the machine.

Legend: Comp–compressor; DV–Drain Valve; FMR–remote fan motor; FMS–self-contained fan motor; F/S–oat switch; HGV–hot gas valve; LLV–liquid line valve; PM–pump motor; SR–service relay; WV–inlet water valve

Cycle

PM stops for  sec.,

4. Pump-Out

F/S in

control

5 minute timer

in control

• Minimum freeze time: 5 minutes

• Maximum freeze time: freeze timer setting

F/S closed

SR energizes, starting

Freeze cycle

operation turned

Comp continues

FMR continues

PM, DV & WV for

over to F/S

HGV de-energized

Comp continues

10 sec. each 1, , 5, or

WV de-energized

FMR continues

10 cycles.

PM energized

FMS energized

LLV energized

HGV energized

FMS de-energized

LLV de-energized

50 sec.

F/S Check

1 to 3 minute timer

in control

PM energized

2. Harvest Cycle 3. Freeze Cycle

Thermistor in

(WV time is 6 minutes or the length of harvest

minus 50 sec., whichever is shorter. PM

energizes and runs for the last 50 sec. of

• Maximum inlet water valve time: 6 minutes

harvest.)

• Maximum harvest time: 0 minutes

Fill Cycle

1. One Minute

control

F/S closed

F/S Check

Comp energized

WV Energized

WV de-energized

Thermistor temp

reaches 48°F (9°C)

(3.9 kΩ or less)

Harvest timer starts

HGV energized

FMR energized

WV continues

LLV de-energized

F/S open

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

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

"WASH" position, power is supplied to the pump motor. With the cleaning valve closed, the cleaner and

sanitizer ow over the outside of the evaporator plate assembly. With the cleaning valve open, the cleaner

and sanitizer ow over both the outside and the inside of the evaporator plate assembly.

Note: Close the cleaning valve after cleaning and sanitizing are complete, otherwise the unit will not re-start

when the control switch is placed in the "ICE" position.

If F/S is open, compressor stops and cycle returns to 1 minute ll

KMD-850MAH, KMD-850MWH, and KMD-850MRH Sequence Flow Chart and Component Operation

Cycle Steps

"G" board will have

Initial startup always

5 second delay

begins here

Legend:

Comp–compressor

DV–drain valve

FMR–remote fan motor

FMS–self-contained fan motor

F/S–oat switch

HGV–hot gas valve

LLV–liquid line valve

PM–pump motor

SR–service relay

WV–inlet water valve

C. Control Board

• A Hoshizaki exclusive solid-state control is employed in KMD-850MAH, KMD-850MWH, and KMD-850MRH Modular Crescent Cubers.

• All models are pretested and factory-adjusted.

CAUTION

1. 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 board or the back of the board to prevent damage to the board.

4. Do not change wiring and connections. Do not misconnect K3, K4, and K5, because the same connector is used for the thermistor, mechanical bin control, and oat switch.

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

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

1. Control Board Layout

Control Products "G" Control Board

"ALARM RESET" Button

Bin Control Switch Closed LED (green)

Bin Control Switch Open LED (yellow)

Part Number

Alarm Buzzer

LED  (green) Hot Gas Valve (HGV) Self-Contained Fan Motor (FMS) (FMS off when LED on)

Power LED (red) (lights when power is supplied to the board)

LED 3 (green) Pump Motor (PM) (PM on, but LED off, at freeze cycle)

LED 4 (green) Inlet Water Valve (WV)

S4 Dip Switch

"OUTPUT TEST" Button (used to test relays on board)

Connector K3 Harvest Control (thermistor)

Connector K4 Mechanical Bin Control

S5 Dip Switch (factory set do not adjust) Connector K5 Float Switch

Label (board revision level indicated on label on side of relay)

Connector K1

Pins #1 through #10 #1, 9 Magnetic Contactor # Hot Gas Valve (HGV) #3 Liquid Line Valve (LLV) #4 Pump Motor (icemaking) #5 Pump Motor (harvest, pump out) #6 Inlet Water Valve (WV) #7, 10 Supply Voltage #8 Open

LED 1 (green) Compressor (Comp)

Switch for "C" board and "ALPINE" board (service boards only)

Connector K Transformer

Control Board

Part Number A379-01

2. Features

a) Maximum Water Supply Period – 6 minutes

The inlet water valve will be open during harvest for 6 minutes or the length of harvest minus 50 seconds, whichever is shorter.

b) Harvest Backup Timer and Freeze Timer

The harvest backup timer shuts down the icemaker if, for two cycles in a row, the harvest cycle takes more than 0 minutes to complete. The control board will signal this problem using  beeps every 3 seconds. The freeze timer shuts down the icemaker if, for two cycles in a row, the freeze cycle takes longer than the time specied to complete. The control board will signal this problem using 3 beeps every 3 seconds. The time is factory set using S4 dip switch 9 &

10. The "ALARM RESET" button on the control board must be pressed with power on to reset either of these safeties.

c) High Temperature Safety

The temperature of the suction line in the refrigeration circuit is limited by the high temperature safety. This protects the unit from excessively high temperatures. If the evaporator temperature rises above 17±7°F (53±4°C), the control board reads a .804 kΩ signal from the thermistor and operates the safety. This shuts down the circuit and the icemaker automatically stops. The control board will signal this problem using 1 beep every 3 seconds. The "ALARM RESET" button on the control board must be pressed with power on to reset the safety.

d) Low Water Safety

The control board checks the position of the oat switch at the end of the initial one minute water ll cycle and at the end of each harvest cycle. If the oat switch is in the up position (electrical circuit closed), the control board changes to the ice making cycle. If the oat switch is in the down position (electrical circuit open), the control board changes to additional one minute water ll cycles until water enters the sump and the oat switch closes. When the oat switch closes, the control board changes to the ice making cycle. The unit will not start without adequate water in the sump. This serves as a low water safety to protect the water pump. For water-cooled model, if the water is shut off, the unit is protected by the high pressure switch.

e) High Voltage and Low Voltage Cut-outs

The maximum and minimum allowable supply voltages of this icemaker are limited by the high voltage and low voltage cut-outs. If miswiring (especially on single phase 3 wire models) causes excessive voltage (147Vac±5% or more) on the control board, the high voltage cut-out shuts down the circuit in 3 seconds and the icemaker automatically stops. The control board will signal this problem using 7 beeps every 3 seconds. The icemaker also automatically stops in cases of insufcient voltage (9Vac±5% or less). The control board will signal this problem using 6 beeps every 3 seconds. When the proper supply voltage is resumed, the icemaker automatically starts running again.

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