Hoshizaki American, Inc. KM-320MAH-E User manual



Hoshizaki

“A Superior Degree

of Reliability”

www.hoshizaki.com

Models

KM-320MAH-E

KM-515MAH-E

KM-650MAH-E

Modular Crescent Cuber

Hoshizaki America, Inc.

SERVICE MANUAL

™

Number: 73170

Issued: 11-13-2008

89/336

73/23



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 the appropriate

Hoshizaki Service Ofce:

UK/Ireland - Hoshizaki UK

TEL : +44 (0)845 456 0585

FAX: +44 (0)46 499080

Holland - Hoshizaki Europe

TEL : +3 (0)0 698499

FAX: +3 (0)0 698768

Belgium/Luxemburg - Hoshizaki Belgium

TEL : +3 (0) 73030

FAX: +3 (0) 7303

Germany/Switzerland/Austria - Hoshizaki Deutschland

TEL : +49 (0)54 980

FAX: +49 (0)54 988

France - Hoshizaki France

TEL : +33 (0) 48639380

FAX: +33 (0) 48639388

Other countries - Hoshizaki Europe

TEL: +3 (0)0 698499

FAX: +3 (0)0 698768

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

CONTENTS

I. Specications ..................................................................................................................... 5

A. KM-30MAH-E (self-contained air-cooled) ...................................................................

5

B. KM-55MAH-E (self-contained air-cooled) ................................................................... 6

C. KM-650MAH-E (self-contained air-cooled) ................................................................... 7

II. General Information ........................................................................................................... 8

A. Dimensions / Connections ............................................................................................ 8

. KM-30MAH-E (self-contained air-cooled) .............................................................. 8

. KM-55MAH-E (self-contained air-cooled) .............................................................. 9

3. KM-650MAH-E (self-contained air-cooled) ............................................................ 0

B. Construction ................................................................................................................ 

. KM-30MAH-E (self-contained air-cooled) ............................................................ 

. KM-55MAH-E (self-contained air-cooled) ............................................................ 

3. KM-650MAH-E (self-contained air-cooled) ............................................................ 3

C. Sequence of Operation ............................................................................................... 4

. One Minute Fill Cycle ............................................................................................ 4

. Initial Harvest Cycle .............................................................................................. 4

3. Freeze Cycle ........................................................................................................ 4

4. Pump-Out Cycle ................................................................................................... 4

5. Normal Harvest Cycle .......................................................................................... 5

D. Control Board ............................................................................................................. 7

. Control Board Layout ............................................................................................ 8

. Features ................................................................................................................ 9

a) Maximum Water Supply Period – 6 minutes ...................................................... 9

b) Harvest Backup Timer and Freeze Timer .......................................................... 9

c) High Temperature Safety ................................................................................... 9

d) Low Water Safety ............................................................................................... 9

e) High Voltage and Low Voltage Cut-outs ............................................................ 9

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

3. Controls and Adjustments ..................................................................................... 

a) Default Dip Switch Settings ................................................................................ 

b) Harvest Timer (S4 dip switch  & ) ................................................................... 

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

d) Pump-Out Frequency Control (S4 dip switch 5 & 6) .......................................... 3

e) Factory Use (S4 dip switch 7 & 8) ...................................................................... 3

f) Freeze Timer (S4 dip switch 9 & 0) ................................................................... 3

4. Control Board Check Procedure ........................................................................... 4

5. Control Board Replacement .................................................................................. 4

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.

4

E. Harvest Control – Thermistor ...................................................................................... 4

. Thermistor Check .................................................................................................. 4

F. Float Switch ................................................................................................................ 5

. Float Switch Check ................................................................................................ 5

. Float Switch Cleaning ............................................................................................ 6

G. Bin Control .................................................................................................................. 6

III. Technical Information ..................................................................................................... 7

A. Water Circuit and Refrigeration Circuit ....................................................................... 7

B. Wiring Diagram ........................................................................................................... 8

. KM-30MAH-E (self-contained air-cooled) ............................................................ 8

. KM-55MAH-E (self-contained air-cooled) ............................................................ 9

3. KM-650MAH-E (self-contained air-cooled) ............................................................ 30

C. Performance Data ...................................................................................................... 3

. KM-30MAH-E (self-contained air-cooled) ............................................................ 3

. KM-55MAH-E (self-contained air-cooled) ............................................................ 3

3. KM-650MAH-E (self-contained air-cooled) ............................................................ 33

IV. Service Diagnosis .......................................................................................................... 34

A. 0-Minute Diagnostic Procedure ............................................................................... 34

B. Diagnostic Charts ....................................................................................................... 36

. No Ice Production .................................................................................................. 36

. Evaporator is Frozen Up ....................................................................................... 39

3. Low Ice Production ................................................................................................ 40

4. Abnormal Ice ......................................................................................................... 4

5. Other ..................................................................................................................... 4

V. Removal and Replacement of Components ................................................................... 43

A. Service for Refrigerant Lines ...................................................................................... 43

. Refrigerant Recovery ............................................................................................ 43

. Brazing .................................................................................................................. 43

3. Evacuation and Recharge (R-404A) ..................................................................... 44

B. Removal and Replacement of Compressor ................................................................ 45

C. Removal and Replacement of Expansion Valve......................................................... 46

D. Removal and Replacement of Hot Gas Valve or Liquid Line Valve............................ 47

E. Removal and Replacement of Evaporator .................................................................. 48

F. Removal and Replacement of Condenser .................................................................. 49

G. Removal and Replacement of Thermistor .................................................................. 50

H. Removal and Replacement of Fan Motor ................................................................... 5

I. Removal and Replacement of Inlet Water Valve.......................................................... 5

J. Removal and Replacement of Pump Motor................................................................. 5

VI. Cleaning and Maintenance ........................................................................................... 53

A. Cleaning and Sanitizing Instructions ........................................................................... 53

. Cleaning Procedure ............................................................................................... 53

. Sanitizing Procedure - Following Cleaning Procedure .......................................... 54

B. Maintenance ............................................................................................................... 56

C. Preparing the Icemaker for Long Storage .................................................................. 56

5

I. Specications

A. KM-320MAH-E (self-contained air-cooled)

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

notice.

AC SUPPLY VOLTAGE 220-240/50/1

AMPERAGE 3.5 A ( 5 Min. Freeze AT 109°F / WT 59°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 *293 (133) 275 (125) 255 (116)

Reference without *marks 80 279 (127) 252 (114) 234 (106)

90 275 (125) *232 (105) 213 (97)

100 273 (124) 228 (103) 196 (89)

FOR THE EUROPEAN MARKET 10/10°C 20/15°C 30/25°C

ICE CAPACITY lbs./day (kg/day) 346 (157) 303 (137) 236 (107)

SHAPE OF ICE Crescent Cube

ICE PRODUCTION PER CYCLE 8 lbs. (3.6 kg) 360pcs.

APPROXIMATE STORAGE CAPACITY N/A

ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F

ELECTRIC W (kWH/100 lbs.) 710(7.3) 650(5.3)

WATER gal./24HR (gal./100 lbs.) 52(22.2) 117(40.1)

EXTERIOR DIMENSIONS (WxDxH) 22" x 27-3/8" x 30-5/16" (560 x 695 x 770 mm)

EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)

WEIGHT Net 153 lbs. (69 kg), Shipping 175 lbs. (79 kg)

CONNECTIONS - ELECTRIC Cord - Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

3/8" 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 Thermostat

COMPRESSOR Hermetic, Model ASE32C3E-CAZ-254

CONDENSER Air-Cooled , Fin and tube type

EVAPORATOR Vertical type, Stainless Steel and Copper

REFRIGERANT CONTROL Thermostatic Expansion Valve

REFRIGERANT CHARGE R404A, 1 lb. 4.3 oz. (575g)

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 Storage Bin

OPERATING CONDITIONS VOLTAGE RANGE 198 - 254 V

AMBIENT TEMP. 45 -100° F

WATER SUPPLY TEMP. 45 - 90° F

WATER SUPPLY PRESSURE 10 - 113 PSIG

6

B. KM-515MAH-E (self-contained air-cooled)

AC SUPPLY VOLTAGE 220-240/50/1

AMPERAGE 7.14 A ( 5 Min. Freeze AT 109°F / WT 59°F)

MINIMUM CIRCUIT AMPACITY 15A

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 *513 (233) 482 (219) 441 (200)

Reference without *marks 80 490 (222) 442 (200) 401 (182)

90 482 (219) *408 (185) 366 (166)

100 474 (215) 398 (181) 328 (149)

FOR THE EUROPEAN MARKET 10/10°C 21/15°C 30/25°C

ICE CAPACITY lbs./day ( kg/day ) 582 (264) 528 (239) 406 (184)

SHAPE OF ICE Crescent Cube

ICE PRODUCTION PER CYCLE 10.2 lbs. (4.6 kg) 480pcs.

APPROXIMATE STORAGE CAPACITY N/A

ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F

ELECTRIC W (kWH/100 lbs.) 1200(7.1) 1080(5.1)

WATER gal./24HR (gal./100 lbs.) 108(26.5) 159(31.1)

EXTERIOR DIMENSIONS (WxDxH) 22" x 27-3/8" x 30-5/16" (560 x 695 x 770 mm)

EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)

WEIGHT Net 151 lbs. (68 kg), Shipping 175 lbs. (79 kg)

CONNECTIONS - ELECTRIC

Cord - Connection

- WATER SUPPLY

Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

3/8" 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 Thermostat

COMPRESSOR Hermetic, Model RST64C1E-CAZ-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. 2.5 oz. (525g)

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 Storage Bin

OPERATING CONDITIONS VOLTAGE RANGE 198 - 254 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.

7

C. KM-650MAH-E (self-contained air-cooled)

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

notice.

AC SUPPLY VOLTAGE 220-240/50/1

AMPERAGE 6.8 A ( 5 Min. Freeze AT 109°F / WT 59°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 *653 (296) 610 (277) 558 (253)

Reference without *marks 80 620 (281) 554 (251) 506 (229)

90 610 (277) *507 (230) 456 (207)

100 602 (273) 495 (225) 409 (186)

FOR THE EUROPEAN MARKET 10/10°C 20/15°C 30/25°C

ICE CAPACITY lbs./day (kg/day) 734 (333) 603 (274) 535 (243)

SHAPE OF ICE Crescent Cube

ICE PRODUCTION PER CYCLE 14 lbs. (6.4 kg) 720pcs.

APPROXIMATE STORAGE CAPACITY N/A

ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F

ELECTRIC W (kWH/100 lbs.) 1200(5.7) 1090(4.0)

WATER gal./24HR (gal./100 lbs.) 94(18.5) 162(24.8)

EXTERIOR DIMENSIONS (WxDxH) 22" x 27-3/8" x 37-7/16" (560 x 695 x 950 mm)

EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)

WEIGHT Net 169 lbs. (77 kg), Shipping 200 lbs. (91 kg)

CONNECTIONS - ELECTRIC

Cord - Connection

- WATER SUPPLY

Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

3/8" 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 Thermostat

COMPRESSOR Hermetic, Model RST64C1E-CAZ-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. 6.6 oz. (640g)

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 Storage Bin

OPERATING CONDITIONS VOLTAGE RANGE 198 - 254 V

AMBIENT TEMP. 45 -100° F

WATER SUPPLY TEMP. 45 - 90° F

WATER SUPPLY PRESSURE 10 - 113 PSIG

8

II. General Information

A. Dimensions / Connections

1. KM-320MAH-E (self-contained air-cooled)

Unit: inches (mm)

Back View Side View Front View

Bottom View

9

2. KM-515MAH-E (self-contained air-cooled)

Unit: inches (mm)

Back View Side View Front View

Bottom View

0

3. KM-650MAH-E (self-contained air-cooled)

Unit: mm (inches)

Back View

Side View

Front View

Bottom View



Bin Control Thermostat Bulb

(Thermostat Body is in Control Box)

Control Switch

Expansion Valve

Compressor

Float Switch

Water Pump

Control Box

Drier

Fan Motor

Hot Gas Valve

Condenser

Water Supply Pipe

Spray Tubes

Transformer

(30V→5V)

High Side

Access Valve

High Pressure

Switch

Strainer

Thermistor

Low Side

Access Valve

Evaporator

Inlet Water Valve

B. Construction

1. KM-320MAH-E (self-contained air-cooled)

Cord with

Fused Plug

(50V, 3A)



Cord with

Fused Plug

(50V, 3A)

Transformer

(30V→5V)

2. KM-515MAH-E (self-contained air-cooled)

Control Switch

Expansion Valve

Compressor

Float Switch

Water Pump

Control Box

Drier

Fan Motor

Hot Gas Valve

Condenser

Water Supply Pipe

Spray Tubes

High Side

Access Valve

High Pressure

Switch

Strainer

Thermistor

Low Side

Access Valve

Liquid Line Valve

Evaporator

Inlet Water Valve

Bin Control Thermostat Bulb

(Thermostat Body is in Control Box)

3

Transformer

(30V→5V)

3. KM-650MAH-E (self-contained air-cooled)

Control Switch

Expansion Valve

Compressor

Float Switch

Water Pump

Control Box

Drier

Fan Motor

Hot Gas Valve

Condenser

Water Supply Pipe

Spray Tubes

High Side

Access Valve

High Pressure

Switch

Strainer

Thermistor

Low Side

Access Valve

Evaporator

Inlet Water Valve

Cord with

Fused Plug

(50V, 3A)

Bin Control Thermostat Bulb

(Thermostat Body is in Control Box)

4

C. Sequence of Operation

The steps in the sequence are as outlined below. When power is supplied, the red

"POWER OK" LED on the control board comes on. A 5-second delay occurs at startup.

Note that the order of the LEDs from the outer edge of the control board is , 4, 3, .

1. One Minute Fill Cycle

LED 4 is on. WV opens and the ll period begins. After  minute, the control board

checks for a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV will remain

energized through additional  minute cycles until water enters the sump and F/S closes.

This serves as a low water safety to protect PM.

2. Initial Harvest Cycle

LEDs , 4, and  are on. WV remains open, Comp and 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 (S4 dip

switch  & ) which is factory set for normal conditions. The harvest timer has settings

of 60, 90, 0, and 80 seconds. For details, see "II.D.3.b) Harvest Timer (S4 dip switch

 & )." When the harvest timer completes its countdown, the harvest cycle is complete

and the freeze cycle starts. The minimum total time allowed by the control board for a

complete harvest cycle is  minutes. WV is energized during harvest for a maximum of

6 minutes or the length of harvest, whichever is shorter. 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 -minute ll if it is open.

3. Freeze Cycle

LED  is on. Comp continues to run, PM and FMS energize, LLV opens, HGV and

WV close, 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 , 3, and  are on. Comp continues to run, HGV opens, LLV closes, and FMS

de-energizes. PM stops for 5 seconds and reverses, taking water from the bottom of

the sump and forcing pressure against the check valve seat allowing water to go through

the check valve and down the drain. At the same time, water ows through the small

tube to power ush F/S. When the pump-out timer (S4 dip switch 3 & 4) stops counting,

the pump out is complete. The st pump out occurs after the st freeze cycle. The pump-

out frequency control (S4 dip switch 5 & 6) determines the frequency of subsequent

pump outs. For details, see "II.D.3.d) Pump-Out Frequency Control (S4 dip switch 5 &

6)."

5

5. Normal Harvest Cycle

LEDs , 4, and  are on. Comp and HGV remain energized. PM stops and WV

energizes. 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 (S4 dip switch  & ) on cycles with a pump-out and to the

pump-out timer's harvest timer on cycles with a pump out. For details, see "II.D.3.b)

Harvest Timer (S4 Dip Switch  & )" and "II.D.3.c) Pump-Out 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 control board for a complete harvest cycle is

 minutes. WV is energized during harvest for a maximum of 6 minutes or the length

of harvest, whichever is shorter. 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 -minute ll if

it is open.

Legend: Comp–compressor; FMS–self-contained fan motor; F/S–oat switch;

HGV–hot gas valve; LLV–liquid line valve; PM–pump motor; WV–inlet water

valve

6

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. The cleaner and sanitizer ow over the outside of

the evaporator plate assembly.

Legend:

Comp-compressor

FMS-self-contained fan motor

F/S-oat switch

HGV-hot gas valve

LLV-liquid line valve

PM-pump motor

WV-inlet water valve

KM-320MAH-E, KM-515MAH-E, KM-650MAH-E Sequence Flow Chart and Component Operation

1. One Minute

Fill Cycle

2. Harvest Cycle 3. Freeze Cycle

4. Pump-Out

Cycle

WV energized

F/S open

F/S closed

WV continues (or

energized)

Comp energized

HGV energized

Thermistor temp

reaches 48°F (9°C)

(3.9 kΩ or less)

Harvest timer starts

F/S open

Comp continues

FMS energized

LLV energized

PM energized

HGV de-energized

WV de-energized

F/S closed

Freeze cycle

operation turned

over to F/S

PM de-energized for

5 sec., then energized

in reverse for 0/0 sec.

each , , 5, or 0 cycles.

Comp continues

HGV energized

WV energized (dependent

on pump-out timer setting)

FMS de-energized

LLV de-energized

F/S check

• Maximum inlet water valve time: 6 minutes

• Maximum harvest time: 0 minutes

Thermistor in

control

 to 3 minute timer

in control

• Minimum freeze time: 5 minutes

• Maximum freeze time: freeze timer setting

5 minute timer

in control

F/S in

control

Initial startup always

begins here. There

is a 5 second delay

from power on.

If F/S is open, compressor stops and cycle returns to  minute ll

7

D. Control Board

• A Hoshizaki exclusive solid-state control board is employed in KM-30MAH-E,

KM-55MAH-E, and KM-650MAH-E Modular Crescent Cubers.

• 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 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. Do not misconnect K3, K4, and K5,

because the same connector is used for the thermistor and oat switch. K4

is not connected.

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

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

8

Control Board

Part Number A40-0 (factory); 2A1410-02 (service)

Type HOS-00A (Control Products - 0 Pin)

Control Products "E" Control Board

1. Control Board Layout

"OUTPUT TEST" Switch

(used to test relays on board)

Connector K3

Harvest Control

(thermistor)

Connector K4

Open

(not connected)

Microprocessor

(board revision level

indicated by last

 digits on label)

Connector K5

Float Switch

Part Number

Connector K

Pins # through #0

#, 9 Magnetic Contactor

# Hot Gas Valve

#3 Liquid Line Valve

Self-Contained Fan Motor

#4 Pump Motor (icemaking)

#5 Pump Motor (pump out)

#6 Inlet Water Valve

#7, 0 Power Supply

#8 Open

Switch for "C" board

and "ALPINE" board

(service board only)

Set to "ALP" for units

covered in this manual.

"ALARM RESET" Switch

Backup Freeze

Timer LED

S4 Dip Switch

Backup Harvest

Timer LED

Alarm Buzzer

Power LED

(lights when

power is supplied

to the board)

Relay LEDs (4)

(indicate which

relays are energized

as listed below)

LED 

Hot Gas Valve (HGV)

Liquid Line Valve

(LLV) & Self-

Contained Fan Motor

(FMS) (LLV & FMS

off when LED on)

LED 3

Pump Motor (PM)

(on at pump out only)

LED 4

Inlet Water Valve (WV)

LED 

Compressor (Comp)

Control Transformer Connector

9

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

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 & 0. For details, see "II.D.3.f) Freeze Timer (S4 dip switch 9 & 0)."

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 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  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  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  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 pump motor from mechanical

seal failure.

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

(47Vac ±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.

0

f) LED Lights and Audible Alarm Safeties

The red LED indicates proper control voltage and will remain on unless a control voltage

problem occurs. At startup, a 5 second delay occurs while the board conducts an

internal timer check. A beep occurs when the power is turned off.

The green LEDs  through 4 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 board is , 4, 3,

. For more information, see "II.C. Sequence of Operation."

Sequence Step LED

Energized

Components

Time LEDs are On

Min. Max. Avg.

 Minute Fill Cycle

4 WV 60 seconds

Harvest Cycle , 4, and  WV, HGV,

Comp

 minutes 0 minutes 3 to 5 minutes

Freeze Cycle  Comp, PM,

FMS, LLV

5 minutes freeze timer

setting

30 to 35 minutes

Pump-Out Cycle , 4*, 3, and



Comp, HGV,

PM, WV*

0 seconds 0 seconds *pump-out timer

setting

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

No. of Beeps

(every 3 sec.)

Type of Alarm Notes

 High Evaporator Temp.

(temperature > 7°F)

(53°C)

Check for harvest problem (stuck HGV or

relay), hot water entering unit, or shorted

thermistor.

 Harvest Backup Timer

(harvest > 0 min. for two

cycles in a row)

Orange LED marked H TIMER lights up.

Check for open thermistor, HGV not opening,

TXV or LLV leaking by, low charge, or

inefcient Comp.

3 Freeze Timer

(freeze > specied setting

for two cycles in a row)

Timer is factory set using

S4 dip switch 9 & 0

Yellow LED marked F TIMER lights up. 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, or

inefcient Comp.

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

6 Low Voltage

(9Vac ±5% or less)

Red LED will turn off if voltage protection

operates.

The control voltage safeties automatically reset

when voltage is corrected.

7 High Voltage

(47Vac ±5% or more)

Legend: Comp–compressor; FMS–self-contained fan motor; F/S–oat switch;

HGV–hot gas valve; LLV–liquid line valve; PM–pump motor; TXV–thermostatic

expansion valve; WV–inlet water valve

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Hoshizaki American, Inc. KM-320MAH-E User manual

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