Hoshizaki American, Inc. KMD-450MAH, KMD-450MWH Service Manual

Hoshizaki America, Inc.

Hoshizaki

Modular Crescent Cuber

Models KMD-450MAH

“A Superior Degree

of Reliability”

www.hoshizaki.com

KMD-450MWH

SERVICE MANUAL

™

Number: 73161 Issued: 9-3-2009

IMPORTANT

Only qualied service technicians should install, service, and maintain the 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, component life, 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 Support (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

Important Safety Information ................................................................................................. 6

I. Specications ..................................................................................................................... 7

A. Icemaker ....................................................................................................................... 7

1. KMD-450MAH (air-cooled) ...................................................................................... 7

. KMD-450MWH (water-cooled) ................................................................................ 8

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

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

1. KMD-450MAH (air-cooled) ...................................................................................... 9

. KMD-450MWH (water-cooled) .............................................................................. 10

B. Sequence of Operation ............................................................................................... 11

1. Sequence Cycles and Shutdown .......................................................................... 11

a) 1-Minute Fill Cycle ........................................................................................... 11

b) Initial Harvest Cycle ........................................................................................ 11

c) Freeze Cycle ................................................................................................... 11

d) Pump-Out Cycle ............................................................................................. 1

e) Normal Harvest Cycle ...................................................................................... 1

f) Shutdown .......................................................................................................... 1

. Sequence Flow Chart ............................................................................................ 14

C. Control Board ............................................................................................................. 15

1. Control Board Layout ............................................................................................ 16

. Features ................................................................................................................ 17

a) Maximum Water Supply Period - 6 minutes .................................................... 17

b) Harvest Backup Timer and Freeze Timer ........................................................ 17

c) High Temperature Safety ................................................................................. 17

d) Low Water Safety ............................................................................................ 17

e) High Voltage and Low Voltage Cut-outs .......................................................... 17

f) LED Lights and Audible Alarm Safeties ............................................................ 18

3. Controls and Adjustments ..................................................................................... 19

a) Default Dip Switch Settings ............................................................................. 19

b) Harvest Timer (S1 dip switch 1 & ) ................................................................ 0

c) Pump-Out Timer (S1 dip switch 3 & 4) ............................................................ 0

d) Pump-Out Frequency Control (S1 dip switch 5 & 6) ........................................ 1

e) Harvest Pump Timer (S1 dip switch 7 & 8) ...................................................... 1

f) Freeze Timer (S1 dip switch 9 & 10) ................................................................ 

g) Pump-Out/Drain Selector (S dip switch 1) ..................................................... 

h) Float Switch Selector (S dip switch ) ........................................................... 3

i) Rell Counter (S dip switch 3 & 4) .................................................................. 3

j) Factory Use (S dip switch 5) ........................................................................... 3

k) Anti-Slush Control (S dip switch 6) ................................................................ 3

D. Bin Control .................................................................................................................. 4

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

F. Thermistor ................................................................................................................... 4

G. Switches ..................................................................................................................... 5

1. Control Switch ....................................................................................................... 5

. Service Switch ....................................................................................................... 5

a) DRAIN .............................................................................................................. 5

b) CIRCULATE .................................................................................................... 5

c) WASH .............................................................................................................. 5

III. Technical Information ..................................................................................................... 6

A. Water Circuit and Refrigeration Circuit ....................................................................... 6

1. KMD-450MAH (air-cooled) .................................................................................... 6

. KMD-450MWH (water-cooled) .............................................................................. 7

Wiring Diagram and Multimeter Access Points ...............................................................8

1. Wiring Diagram ...................................................................................................... 8

. Multimeter Access Points ...................................................................................... 9

a) Diagnostic Connector ...................................................................................... 9

b) Compressor Terminal Block ............................................................................ 9

C. Performance Data ...................................................................................................... 30

1. KMD-450MAH (air-cooled) .................................................................................... 30

. KMD-450MWH (water-cooled) .............................................................................. 31

IV. Service Diagnosis .......................................................................................................... 3

A. Diagnostic Procedure ................................................................................................ 3

B. Control Board Check .................................................................................................. 36

C. Bin Control Check and Cleaning ................................................................................ 37

1. Bin Control Check ................................................................................................. 37

. Bin Control Cleaning ............................................................................................. 37

D. Float Switch Check and Cleaning ............................................................................... 38

1. Float Switch Check ................................................................................................ 38

. Float Switch Cleaning ............................................................................................ 39

E. Thermistor Check ....................................................................................................... 41

F. Diagnostic Charts ........................................................................................................ 4

1. No Ice Production .................................................................................................. 4

. Evaporator is Frozen Up ....................................................................................... 45

3. Low Ice Production ................................................................................................ 47

4. Abnormal Ice ......................................................................................................... 48

5. Other ..................................................................................................................... 49

V. Removal and Replacement of Components ................................................................... 50

A. Service for Refrigerant Lines ...................................................................................... 50

1. Refrigerant Recovery ............................................................................................ 50

. Brazing .................................................................................................................. 51

3. Evacuation and Recharge (R-404A) ..................................................................... 51

B. Removal and Replacement of Compressor ................................................................ 5

C. Removal and Replacement of Expansion Valve......................................................... 53

D. Removal and Replacement of Hot Gas Valve or Liquid Line Valve ........................... 54

E. Removal and Replacement of Evaporator .................................................................. 55

F. Removal and Replacement of Air-Cooled Condenser ................................................ 56

G. Removal and Replacement of Water-Cooled Condenser .......................................... 56

H. Removal and Replacement of Water Regulating Valve (water-cooled model) ........... 58

I. Adjustment of Water Regulating Valve (water-cooled model) ...................................... 59

J. Removal and Replacement of Thermistor ................................................................... 60

K. Removal and Replacement of Fan Motor (air-cooled and remote air-cooled models) 61

L. Removal and Replacement of Water Valves............................................................... 61

M. Removal and Replacement of Pump Motor ............................................................... 6

N. Removal and Replacement of Control Board ............................................................. 6

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

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

1. Cleaning Procedure ............................................................................................... 63

. Sanitizing Procedure - Following Cleaning Procedure .......................................... 65

B. Maintenance ............................................................................................................... 66

C. Preparing the Icemaker for Long Storage .................................................................. 67

Important Safety Information

Throughout this manual, notices appear to bring your attention to situations which could result in death, serious injury, or damage to the unit.

WARNING Indicates a hazardous situation which could result in death or

serious injury.

CAUTION Indicates a situation which could result in damage to the unit.

IMPORTANT Indicates important information about the use and care of the

unit.

WARNING

This icemaker should be destined only to the use for which it has been expressly conceived. Any other use should be considered improper and therefore dangerous. The manufacturer cannot be held responsible for eventual damage caused by improper, incorrect, and unreasonable use.

To reduce the risk of death, electric shock, serious injury, or re, follow basic precautions including the following:

• Electrical connection must be hard-wired and must meet national, state, and local electrical code requirements. Failure to meet these code requirements could result in death, electric shock, serious injury, re, or severe damage to equipment.

• This unit requires an independent power supply. See the nameplate for proper voltage and breaker/fuse size. Failure to use a proper breaker or fuse can result in a tripped breaker, blown fuse, or damage to existing wiring. This could lead to heat generation or re.

• THIS UNIT MUST BE GROUNDED. Failure to properly ground this unit could result in death or serious injury.

• This unit should be disassembled or repaired only by qualied service personnel to reduce the risk of electric shock, injury, or re.

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

I. Specications

AC SUPPLY VOLTAGE 115-120/60/1 (3 wire with netrual for 115V) AMPERAGE 10.0 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR. Temp.(°F) 50 70 90 lbs./day ( kg/day ) 70 *457 (207) 436 (198) 398 (180) Reference without *marks 80 441 (200) 409 (186) 365 (165)

90 436 (198) *387 (176) 344 (156)

100 425 (193) 377 (171) 304 (138) SHAPE OF ICE Crescent Cube ICE PRODUCTION PER CYCLE 9.6 lbs. (4.3 kg) 432pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 880(5.48) 810(4.28) WATER gal./24HR (gal./100 lbs.) 73(18.9) 192(42.1) CEC/CEE TIER LEVEL 3 ENERGY STAR YES EXTERIOR DIMENSIONS (WxDxH) 30" x 24-1/4" x 22-1/8" (762 x 617 x 562 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 130 lbs. (59 kg), Shipping 170 lbs. (77 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 RST45C1E-CAA-202 CONDENSER Air-Cooled , Fin and tube type EVAPORATOR Vertical type, Stainless Steel and Copper REFRIGERANT CONTROL Thermostatic Expansion Valve REFRIGERANT CHARGE R404A, 1 lb. 5.2 oz. (600g) 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 104 - 127 V

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

WATER SUPPLY PRESSURE 10 - 113 PSIG

A. Icemaker

1. KMD-450MAH (air-cooled)

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

notice.

2. KMD-450MWH (water-cooled)

AC SUPPLY VOLTAGE 115-120/60/1 (3 wire with netrual for 115V) AMPERAGE 8.5A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR. Temp.(°F) 50 70 90 lbs./day ( kg/day ) 70 *460 (209) 447 (203) 415 (188) Reference without *marks 80 450 (204) 429 (195) 389 (177)

90 447 (203) *415 (188) 377 (171)

100 436 (198) 406 (184) 343 (156) SHAPE OF ICE Crescent Cube ICE PRODUCTION PER CYCLE 9.3 lbs. (4.2 kg) 432pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 790(4.55) 790(4.14) WATER gal./24HR (gal./100 lbs.) 74(17.8) 145(31.6) WATER COOLED CONDENSER 523(126) 315(68)

gal./24HR (gal./100 lbs.) CEC/CEE TIER LEVEL 3 ENERGY STAR N/A EXTERIOR DIMENSIONS (WxDxH) 30" x 24-1/4" x 22-1/8" (762 x 617 x 562 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 130 lbs. (59 kg), Shipping 170 lbs. (77 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 RST45C1E-CAA-202 CONDENSER Water-cooled, Tube in tube type EVAPORATOR Vertical type, Stainless Steel and Copper REFRIGERANT CONTROL Thermostatic Expansion Valve REFRIGERANT CHARGE R404A, 1 lb. 0.9 oz. (480g) 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 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.

II. General Information

A. Construction

1. KMD-450MAH (air-cooled)

Spray Tube

Inlet Water Valve

Water Tank

Water Guide

Spray Guide

Wash Valve

Water Supply Inlet

Expansion Valve

Junction Box

Hot Gas Valve

Condenser

Condenser Fan Motor

Control Switch

Service Switch

Drain Valve

Drier

Compressor

Pump Motor

Control Box

Float Switch

Bin Control

2. KMD-450MWH (water-cooled)

Water Guide

Spray Guide

Spray Tube

Wash Valve

Water Supply Inlet

Expansion Valve

Junction Box

Hot Gas Valve

Condenser

Inlet Water Valve

Drain Valve

Water Tank

Pump Motor

Water Regulator

Control Switch

Service Switch

Compressor

Drier

Control Box

Float Switch

Bin Control

B. Sequence of Operation

1. Sequence Cycles and Shutdown

The steps in the sequence are as outlined below. When power is supplied, CB "POWER OK" LED comes on. There is a 5-second delay before startup. Note that the order of the component LEDs from the outer edge of CB is 5, 6, 8, 9, 4, 7.

a) 1-Minute Fill Cycle

LED 8 is on. WV energizes and the 1-minute ll cycle begins. After 1 minute, CB checks for a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV remains energized through additional 1-minute ll cycles until water lls the tank and closes F/S. This serves as a low water safety to protect PM.

b) Initial Harvest Cycle

LEDs 5, 6, and 8 are on. WV remains energized, Comp, FMR, HGV energize. CB monitors the warming of the evaporator via the thermistor located on the suction line. When the thermistor reaches 48°F (9°C), CB reads a 3.9 kΩ signal from the thermistor and turns harvest termination over to the harvest timer (S1 dip switch 1 & ). The harvest timer has settings of 60, 90, 10, and 180 seconds. For details, see "II.C.3.b) Harvest Timer (S1 dip switch 1 & )." WV is energized during harvest for a maximum of 6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (harvest pump timer (S1 dip switch 7 & 8)), whichever is shorter. For details, see "II.C.3.e) Harvest Pump Timer (S1 dip switch 7 & 8)." LED 8 goes off when WV de-energizes. LED 7 comes on and PM energizes and runs for the last 0, 10, 30, or 50 seconds of harvest depending on the harvest pump timer setting. This circulates water over the evaporator for the last 0, 10, 30, or 50 seconds of harvest. When the harvest timer expires, the harvest cycle is complete. CB checks the position of F/S and proceeds to the freeze cycle if it is closed or calls for a 1-minute ll cycle if it is open. The minimum total time allowed by CB for a complete harvest cycle is  minutes.

c) Freeze Cycle

LEDs 5 & 7 are on. Comp and FMR remain energized, PM energizes or remains energized depending on the harvest pump timer (S1 dip switch 7 & 8) setting. FM and LLV energize, HGV and WV (may de-energize during harvest cycle) de-energize. CB monitors the cooling of the evaporator via the thermistor located on the suction line. When the thermistor drops to 36°F (°C), CB reads a 5.5 kΩ signal from the thermistor and starts a 5-minute short cycle protection timer. CB will not accept a signal from F/S until the 5-minute timer expires. After the 5-minute timer expires, F/S assumes control. As ice builds on the evaporator, the water level in the tank lowers. The freeze cycle continues until F/S opens and terminates the cycle. The oat switch selector (S dip switch ) and the rell counter (S dip switch 3 & 4) allow certain models to use a double F/S to rell the water tank during the freeze cycle. The KMD-450MAH and KMD-450MWH use a single F/S and do not rell. For details, see "II.C.3.h) Float Switch Selector (S dip switch )" and "II.C.3.i) Rell Counter (S dip switch 3 & 4)." CAUTION! Do not adjust S2 dip switch 2, 3, or 4 out of the factory

default position on this model. These dip switches must be left in the factory default position or this unit will not operate correctly.

The anti-slush control (S dip switch 6) helps prevent slushing during the freeze cycle on certain models. When activated, the control board monitors the cooling of the

evaporator via the thermistor located on the suction line. When the thermistor drops to 34°F (1°C), the control board reads a 5.8 kΩ signal from the thermistor and de-energizes PM for 10 seconds. The anti-slush control is deactivated on the KMD-450MAH and KMD-450MWH. CAUTION! Do not adjust S2 dip switch 6 out of the factory default

position on this model. This dip switch must be left in the factory default position or this unit will not operate correctly.

d) Pump-Out Cycle

LEDs 5, 6, 4, and 7 are on. Comp and FMR remain energized, HGV energizes, LLV and FM de-energize. DV energizes after a -second delay. PM de-energizes for  seconds and then re-energizes, or de-energizes and stays off depending on the pump-out/drain selector (S dip switch 1) setting. For details, see "II.C.3.g) Pump-Out/Drain Selector (S dip switch 1)." When the pump-out/drain selector is set to pump-out, PM takes water from the tank and forces it through DV and down the drain. When the pump-out/drain selector is set to drain, water drains by gravity through DV. CAUTION! Do not adjust

S2 dip switch 1 out of the factory default position on this model. This dip switch must be left in the factory default position or this unit will not operate correctly.

Pump-out lasts 10 or 0 seconds depending on the pump-out timer (S1 dip switch 3 & 4) setting. When the pump-out timer expires, the pump-out is complete. For details, see "II. C.3.c) Pump-Out Timer (S1 dip switch 3 & 4)." The rst pump-out occurs after the 1st freeze cycle, then every 10th cycle thereafter. The pump-out frequency is factory set, and generally no adjustment is required. However, if the icemaker needs a pump-out more often due to local water conditions, the pump-out frequency can be adjusted. The pump-out frequency control (S1 dip switch 5 & 6) can be set to have a pump-out occur every cycle, or every , 5, or 10 cycles. For details, see "II.C.3.d) Pump-Out Frequency Control (S1 dip switch 5 & 6)."

e) Normal Harvest Cycle

Same as the initial harvest cycle. See "II.B.1.b) Initial Harvest Cycle."

Note: Unit continues to cycle until BC is satised or power is turned off. The unit always

restarts at the 1-minute ll cycle.

f) Shutdown

When BC is activated (BC open), the "POWER OK" LED ashes. There is a delay before the shutdown sequence begins. The delay varies depending on the cycle the icemaker is in at the time of activation. For details, see the table below.

Cycle at Bin Control Activation Delay Before Shutdown Sequence Begins

Fill Cycle 15 seconds

Harvest Cycle 15 seconds after the next freeze cycle starts

Freeze Cycle 15 seconds if BC is activated between the beginning of freeze and

termination of the 5-minute short cycle protection timer (timer starts when the thermistor temperature drops to 36°F (°C) (5.5 kΩ or more)). After this time, the unit will not shut down until the next harvest cycle is complete.

After the delay, all components de-energize. DV energizes after  seconds. PM energizes after  seconds or stays off depending on the pump-out/drain selector (S dip switch 1) setting. For details, see "II.C.3.g) Pump-Out/Drain Selector (S dip

1

switch 1)." When the pump-out/drain selector is set to pump-out, PM takes water from the tank and forces it through DV and down the drain. When the pump-out/drain selector is set to drain, water drains by gravity through DV. CAUTION! Do not adjust S2 dip

switch 1 out of the factory default position on this model. This dip switch must be left in the factory default position or this unit will not operate correctly. The water

tank drains for a maximum of 5 minutes or until F/S opens. DV and PM (if applicable) then de-energize. When BC closes again calling for ice, the unit starts at the 1-minute ll cycle. There is a 90-second minimum off time before the icemaker can restart.

Legend: BC–bin control; CB–control board; Comp–compressor; DV–drain valve; FM –fan

motor; FMR–fan motor-remote; F/S–oat switch; HGV–hot gas valve; LLV–liquid line valve; PM–pump motor; WV–inlet water valve

2. Sequence Flow Chart

 seconds (S dip

switch 1), then

10th cycle (S1 dip

switch 5 & 6)

• Factory set for every

4. Pump-Out Cycle

(S1 dip switch 9 & 10)

• Minimum freeze time: 5 minutes

• Maximum freeze time: freeze timer setting

3. Freeze Cycle

runs for 10/0 sec.

• PM stops for

(S1 dip switch 3 & 4)

F/S in

control

5-minute

timer in

control

Thermistor

in control

Comp continues

F/S open or

freeze timer

expires

F/S closed

Comp continues

FMR continues

HGV energized

DV & PM de-energized for  sec.,

then energized for

10/0 sec.

FM de-energized

LLV de-energized

Thermistor temperature

drops to 36°F (°C)

(5.5 kΩ or more).

5-minute short cycle

protection timer starts.

FMR continues

PM continues

FM energized

LLV energized

HGV de-energized

To 1 above

No ice pressing

against BC

actuator.

Icemaker starts at

"1. 1-Minute Fill

4. Ice Level Lowered

Minimum off time:

90 seconds

3. Icemaker Off

Until F/S Opens

Maximum drain

2. Water Tank Drains

Cycle."

time: 5 minutes

BC closed

"POWER OK" LED on

(not ashing)

F/S open

DV de-energized

PM de-energized

All components

de-energized.

DV energized after  sec.

PM energized after  sec.

F/S check

PM energized

0, 10, 30, or 50 sec.

(S1 dip switch 7 & 8)

Harvest Pump Timer

1 to 3-min. timer in control

KMD-450MAH, KMD-450MWH

(S1 dip switch 1 & )

WV de-energized

Thermistor temperature

reaches 48°F (9°C)

F/S open

(3.9 kΩ or less).

Harvest timer starts.

"H" Control Board Sequence Flow Chart

Thermistor in

• Maximum harvest time: 0 min.

control

F/S closed

F/S check

WV continues

Comp energized

FMR energized

HGV energized

F/S open

WV energized

If F/S is open, compressor stops and cycle returns to 1-Minute Fill Cycle

10, 30, or 50 sec. (S1 dip switch 7 & 8), whichever

is shorter.

• WV time: 6 min. or the length of harvest minus 0,

2. Harvest Cycle

Cycle

1. 1-Minute Fill

termination of 5-minute short cycle protection timer (timer starts when thermistor

temperature drops to 36°F (°C) (5.5 kΩ or more)). After this time, unit will not

Delay After Bin Control is Activated:

• Fill Cycle–15 seconds.

• Harvest Cycle–15 seconds after freeze cycle starts.

1. Bin Full

shut down until next harvest cycle is complete.

• Freeze Cycle–15 seconds if BC is activated between beginning of freeze and

BC open

"POWER OK" LED ashing

the evaporator for extended periods of time.

the inside and outside surfaces of the evaporator.

DRAIN Power is supplied to the pump motor and drain valve. This drains the water tank.

CIRCULATE Power is supplied to the pump motor only. This can be used to circulate cleaner over the outside surface of

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

When in the "SERVICE" position, the control switch supplies power to the service switch and the icemaker is in service mode. The

service switch has three positions: "DRAIN," "CIRCULATE," and "WASH." See the information below for details of each function.

WASH Power is supplied to the pump motor and wash valve. This is used to circulate cleaner and sanitizer over both

Cycle Steps

Initial startup

begins here

after 5-sec.

delay

Bin Control

Shutdown

and Restart

BC Operation

Legend:

BC–bin control

Comp–compressor

DV–drain valve

FM–fan motor

FMR–fan motor-remote

F/S–oat switch

HGV–hot gas valve

LLV–liquid line valve

PM–pump motor

WV–inlet water valve

C. Control Board

• A Hoshizaki exclusive solid-state control board is employed in KMD-450MAH and KMD-450MWH Modular Crescent Cubers.

• All models are pretested and factory set.

• For a control board check procedure, see "IV.B. Control Board Check."

CAUTION

1. The control board is 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 control board.

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

4. Do not change wiring and connections.

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

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

1. Control Board Layout

• Relay LEDs (6) (indicate which relays are energized as listed below)

• LED 5 (X1 Relay) Compressor (Comp) Fan Motor-Remote (FMR)

• LED 6 (X2 Relay) Hot Gas Valve (HGV) Fan Motor (FM) Liquid Line Valve (LLV) (FM and LLV off when LED on)

• LED 8 (X4 Relay) Inlet Water Valve (WV) (WV1) on units with  inlet water valves

• LED 9 (X5 Relay) Inlet Water Valve  (WV) on units with  inlet water valves

• LED 4 (X6 Relay) Drain Valve (DV)

• LED 7 (X3 Relay) Pump Motor (PM)

"H" Control Board

• K7 Connector Transformer

• K3 Connector Magnetic Contactor

• "POWER OK" LED (Lights when power is supplied to the board. Flashes when bin control is activated.)

• K5 Connector Pins #1 Fan Motor (FM) Liquid Line Valve (LLV) # Hot Gas Valve #3 Pump Motor #4 Inlet Water Valve #5 Open #6 Drain Valve

• K6 Connector Open

• K1 Connector Pins #1, 3 Float Switch # Open #4, 5 Bin Control #6, 7 Thermistor #8, 9 Open

• S1 Dip Switch

• S2 Dip Switch

"H" Control Board

Part Number P00013-0

• Alarm Buzzer

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

• "ALARM RESET" Button

2. Features

a) Maximum Water Supply Period - 6 minutes

The inlet water valve is open during harvest for 6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (harvest pump timer (S1 dip switch 7 & 8)), whichever is shorter. For details, see "II.C.3.e) Harvest Pump Timer (S1 dip switch 7 & 8)."

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 signals 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 signals this problem using 3 beeps every 3 seconds. The time is factory set using S1 dip switch 9 & 10. For details, see "II.C.3.f) Freeze Timer (S1 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 reaches 17°F±7°F (53°C±4°C), the control board reads a .8 kΩ signal from the thermistor and shuts down the icemaker. 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 1-minute 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 next cycle. If the oat switch is in the down position (electrical circuit open), the control board changes to additional 1-minute ll cycles until water lls the tank and closes the oat switch. When the oat switch closes, the control board changes to the next cycle. The unit will not start without adequate water in the tank. This serves as a low water safety to protect the water pump. For water-cooled model, if the condenser water supply 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), 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 signals this problem using 6 beeps every 3 seconds. When the proper supply voltage is resumed, the icemaker automatically starts running again.

f) LED Lights and Audible Alarm Safeties

At startup, a 5-second delay occurs to stabilize the circuit. The "POWER OK" LED indicates proper control voltage and remains on unless a control voltage problem occurs. The "POWER OK" LED ashes continuously when the bin is full and PM and DV energize for a maximum of 5 minutes to drain the water tank. LEDs 4 through 9 energize and sequence from initial startup as listed in the table below. Note that the order of the LEDs from the outer edge of the control board is 5, 6, 8, 9, 4, 7. For details, see "II.B. Sequence of Operation."

Sequence Step LED

1-Minute Fill Cycle 8 WV 1 minute Harvest Cycle 5, 6, 8 Comp, FMR, HGV, WV  minutes 0 minutes 3 to 5 minutes Harvest Pump Timer 5, 6, 7 Comp, FMR, HGV, PM 0 seconds 50 seconds harvest pump

Freeze Cycle 5, 7 Comp, FM/FMR, PM,

Pump-Out Cycle 5, 6, 4, 7* Comp, FMR, HGV, DV,

Energized

Components

LLV

PM*

Min. Max. Avg.

5 minutes freeze timer

10 seconds 0 seconds *pump-out/drain

Time LEDs are On

timer setting 30 to 35 minutes

setting

selector setting

The built-in safeties shut down the unit and have alarms as listed below.

No. of Beeps

(every 3 sec.)

1 High Evaporator Temp.

(temperature > 17°F) (53°C)

 Harvest Backup Timer

(harvest > 0 min. for two cycles in a row)

3 Freeze Timer

(freeze > freeze timer setting for two cycles in a row)

To reset the above safeties, press the "ALARM RESET" button with the power supply on.

6 Low Voltage

(9Vac±5% or less)

7 High Voltage

(147Vac±5% or more)

Type of Alarm Notes

Check for harvest problem (stuck HGV or relay), hot water entering unit, stuck HM, or shorted thermistor.

Check for open thermistor, HGV not opening, TXV or LLV leaking by, low charge, inefcient Comp, or WRV leaking by.

Check for F/S stuck closed (up), WV leaking by, HGV leaking by, PM not pumping, TXV not feeding properly, LLV not opening, low charge, HM not bypassing, or inefcient Comp.

"POWER OK" LED turns off if voltage protection operates. The control voltage safeties automatically reset when voltage is corrected.

Legend: Comp–compressor; DV–drain valve; FM–fan motor; FMR–fan motor-remote;

F/S–oat switch; HGV–hot gas valve; HM–headmaster (C.P.R.); LLV–liquid line valve; PM–pump motor; TXV–thermostatic expansion valve; WRV–water regulating valve; WV–inlet water valve

3. Controls and Adjustments

CAUTION

Dip switches are factory set. Failure to maintain factory settings may adversely affect performance and warranty coverage. For more information, contact Hoshizaki Technical Support at 1-800-33-1940.

a) Default Dip Switch Settings

The dip switches are factory set to the following positions:

S1 Dip Switch

Dip Switch No. 1 2 3 4 5 6 7 8 9 10

KMD-450MAH OFF OFF ON ON ON ON ON ON OFF ON

KMD-450MWH OFF OFF ON ON ON ON ON ON OFF OFF

S2 Dip Switch (Do Not Adjust)

Dip Switch No.

KMD-450MAH ON OFF OFF OFF OFF ON

KMD-450MWH ON OFF OFF OFF OFF ON

1 2 3 4 5 6

S1 Dip Switch S2 Dip Switch

Freeze Timer (9 & 10)

Anti-Slush Control (6)

Harvest Pump Timer (7 & 8)

Pump-Out Frequency Control (5 & 6)

Factory Use (5)

Rell Counter (3 & 4)

Float Switch Selector ()

Pump-Out Timer (3 & 4)

Harvest Timer (1 & )

Pump-Out/Drain Selector (1)

b) Harvest Timer (S1 dip switch 1 & 2)

The harvest timer starts when the thermistor reaches 48°F (9°C) at the evaporator outlet and the control board reads the thermistor's 3.9 kΩ signal. The harvest timer is factory set, and generally no adjustment is required. However, a setting longer than the factory setting may be advised in cases where the ush provided at harvest needs to be prolonged for extra cleaning. Before changing this setting, contact Hoshizaki Technical Support at 1-800-33-1940 for recommendations. Keep in mind that setting the harvest timer to a longer setting decreases 4-hour production. Note that the pump-out timer (S1 dip switch 3 & 4) acts in place of the harvest timer during cycles with a pump-out. For details, see "II.C.3.c) Pump-Out Timer (S1 dip switch 3 & 4)."

S1 Dip Switch Setting

No. 1 No. 2

OFF OFF 60

ON OFF 90

OFF ON 10

ON ON 180

Time

(seconds)

c) Pump-Out Timer (S1 dip switch 3 & 4)

When a pump-out is called for, the pump motor de-energizes after the preceding freeze cycle.  seconds later, the pump motor and drain valve energize. The pump motor takes water from the tank and forces it through the drain valve and down the drain. The pump motor drains the water tank for the time determined by the pump-out timer. The pump-out timer also acts in place of the harvest timer during cycles with a pump-out. The pump-out timer is factory set, and generally no adjustment is required. However, if the default is 10 seconds and the icemaker needs a longer pump-out due to local water conditions, the pump-out timer can be adjusted to 0 seconds.

S1 Dip Switch Setting Time (seconds)

No. 3 No. 4 T1 T2

OFF OFF 10 10

ON OFF 10 180

OFF ON 0 10

ON ON 0 180

T1: Time to drain the water tank T: Harvest timer at pump-out

0

d) Pump-Out Frequency Control (S1 dip switch 5 & 6)

The pump-out frequency control is factory set to drain the water tank every 10 cycles, and generally no adjustment is required. However, if the icemaker needs a pump-out more often due to local water conditions, 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. After startup, the rst pump-out occurs after the 1st freeze cycle.

S1 Dip Switch Setting

No. 5 No. 6

OFF OFF Every cycle

ON OFF Every  cycles

OFF ON Every 5 cycles

ON ON Every 10 cycles

Frequency

e) Harvest Pump Timer (S1 dip switch 7 & 8)

CAUTION

Factory set for proper operation. Do not adjust. Adjustment outside of the factory default setting may result in damage to the icemaker.

Depending on the harvest pump timer setting, the pump motor energizes and runs for the last 0, 10, 30, or 50 seconds of harvest. When the pump motor is on, water circulates over the evaporator. The water valve is energized during harvest for a maximum of 6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (determined by the harvest pump timer setting), whichever is shorter.

S1 Dip Switch Setting

No. 7 No. 8

OFF OFF 0

ON OFF 10

OFF ON 30

ON ON 50

Time

(seconds)

1

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