Hoshizaki KM-320MAH, KM-320MWH User Manual

Hoshizaki

“A Superior Degree

of Reliability”

www.hoshizaki.com

Models
KM-320MAH
KM-320MWH

Modular Crescent Cuber

Hoshizaki America, Inc.

Number: 73132
Issued: 1-24-2006
Revised: 11-30-2006

SERVICE MANUAL

IMPORTANT

Only qualified service technicians should attempt to service or maintain this
icemaker. No such service or maintenance should be undertaken until the
technician has thoroughly read this Service Manual.

HOSHIZAKI provides this manual primarily to assist qualified 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 or write to the HOSHIZAKI Technical Support Department for
assistance.

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

Attn: HOSHIZAKI Technical Support Department

Phone: [phone] Technical Service
[phone]
Fax: [phone]
[phone]

Web Site: www.hoshizaki.com

NOTE: To expedite assistance, all correspondence/communication MUST include the

following information:

• Model Number

• Serial Number

• Complete and detailed explanation of the problem

2

Please review this manual. It should be read carefully before the icemaker is serviced or
maintenance operations are performed. Only qualified service technicians should service
and maintain the icemaker. This manual should be made available to the technician prior to
service or maintenance.

CONTENTS

I. Specifications ...................................................................................................................... 5

A. KM-320MAH (air-cooled) .............................................................................................. 5

B. KM-320MWH (water-cooled) ......................................................................................... 6

II. General Information ........................................................................................................... 7

A. Construction .................................................................................................................. 7

1. KM-320MAH (air-cooled) ......................................................................................... 7

2. KM-320MWH (water-cooled) ................................................................................... 8

B. Controller Board ............................................................................................................ 9

1. Solid-State Control .................................................................................................. 9

2. Controller Board ...................................................................................................... 9

3. Sequence .............................................................................................................. 13

4. Controls and Adjustments .................................................................................... 16

5. Checking the Controller Board .............................................................................. 19

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

A. Water Circuit and Refrigerant Circuit ........................................................................... 21

1. KM-320MAH .......................................................................................................... 21

2. KM-320MWH ......................................................................................................... 22

B. Wiring Diagram ............................................................................................................ 23

1. KM-320MAH, KM-320MWH .................................................................................. 23

C. Timing Chart .............................................................................................................. 24

D. Performance Data ....................................................................................................... 26

1. KM-320MAH .......................................................................................................... 26

2. KM-320MWH ......................................................................................................... 27

IV. Service Diagnosis ........................................................................................................... 28

A. No Ice Production........................................................................................................ 28

B. Evaporator is Frozen Up.............................................................................................. 31

C. Low Ice Production ..................................................................................................... 33

D. Abnormal Ice ............................................................................................................... 33

E. Other ........................................................................................................................... 33

V. Removal and Replacement of Components .................................................................... 34

A. Service for Refrigerant Lines ...................................................................................... 34

1. Refrigerant Recovery ............................................................................................. 34

2. Evacuation and Recharge (R-404A) ...................................................................... 34

B. Brazing ........................................................................................................................ 35

C. Removal and Replacement of Compressor ................................................................ 36

D. Removal and Replacement of Drier ............................................................................ 37

E. Removal and Replacement of Expansion Valve .......................................................... 37

F. Removal and Replacement of Hot Gas Valve and Line Valve ...................................... 38

G. Removal and Replacement of Evaporator .................................................................. 39

H. Removal and Replacement of Thermistor ................................................................... 40

I. Removal and Replacement of Fan Motor ..................................................................... 41

J. Removal and Replacement of Water Valve .................................................................. 41

3

K. Removal and Replacement of Pump Motor ................................................................ 42

L. Removal and Replacement of Spray Tubes ................................................................. 42

M. Removal and Replacement of Water Regulating Valve – Water-Cooled Model Only .

N. Adjustment Of Water Regulating Valve – Water-Cooled Model Only .......................... 44

VI. Cleaning and Maintenance Instructions ......................................................................... 45

A. Preparing the Icemaker for Long Storage ................................................................... 45

B. Cleaning and Sanitizing Instructions ........................................................................... 47

1. Cleaning Procedure ............................................................................................... 48

2. Sanitizing Procedure - Following Cleaning Procedure ..........................................

C. Maintenance ............................................................................................................... 50

43

49

4

I. Specifications

SPECIFICATION NO. 05A013 ISSUED: 11/29/2005

ITEM: HOSHIZAKI MODULAR CRESCENT CUBER
MODEL: KM-320MAH

AC SUPPLY VOLTAGE 115/60/1
AMPERAGE 9.7 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 *325 (147) 311 (141) 287 (130)
Reference without *marks 80 315 (143) 293 (133) 265 (120)

90 311 (141) *278 (126) 251 (114)

100 304 (138) 272 (123) 226 (103)
SHAPE OF ICE Crescent Cube
ICE PRODUCTION PER CYCLE 7.2 lbs. (3.3 kg) 360 pcs.
APPROXIMATE STORAGE CAPACITY N/A
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 800(6.9) 750(5.5)
WATER gal./24HR (gal./100 lbs.) 51(18.4) 117(35.9)
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 123 lbs. (56 kg), Shipping 153 lbs. (70 kg)
CONNECTIONS - ELECTRIC Permanent - 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-CAA
CONDENSER Air-Cooled , Fin and tube type
EVAPORATOR Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R-404A, 1 lb. 4.3 oz. (575g)
DESIGN PRESSURE High 467PSIG, Low 210PSIG
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 104 - 127 V

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

WATER SUPPLY PRESSURE 10 - 113 PSIG

A. KM-320MAH (air-cooled)

Note: We reserve the right to make changes in specifications and design without prior

notice.

5

AC SUPPLY VOLTAGE 115/60/1
AMPERAGE 8.2 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 *352 (160) 348 (158) 324 (147)
Reference without *marks 80 349 (158) 342 (155) 309 (140)

90 348 (158) *337 (153) 308 (140)

100 337 (153) 330 (150) 281 (127)
SHAPE OF ICE Crescent Cube
ICE PRODUCTION PER CYCLE 7.2 lbs. (3.3 kg) 360 pcs.
APPROXIMATE STORAGE CAPACITY N/A
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 730(5.2) 730(5.0)
WATER gal./24HR (gal./100 lbs.) 57(16.8) 103(29.4)
WATER COOLED CONDENSER 528(157) 327(93)

gal./24HR (gal./100 lbs.)
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 123 lbs. (56 kg), Shipping 153 lbs. (70 kg)
CONNECTIONS - ELECTRIC Permanent - 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 Pressure Regulator
BIN CONTROL SYSTEM Thermostat
COMPRESSOR Hermetic, Model ASE32C3E-CAA
CONDENSER Water-cooled, Tube in tube type
EVAPORATOR Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R-404A, 1 lb. 0.8 oz. (486g)
DESIGN PRESSURE High 427PSIG, Low 210PSIG
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 104 - 127 V

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

B. KM-320MWH (water-cooled)

Note: We reserve the right to make changes in specifications and design without prior

notice.

6

II. General Information

A. Construction

1. KM-320MAH (air-cooled)

Evaporator

Cleaning Valve

Bin Control
Thermostat

Spray Tubes

Expansion Valve

Control Switch

Water Supply Inlet

Hot Gas Valve

Condenser

Fan Motor

Float Switch

Water Pump

Drier

Compressor

Control Box
(shown transparent to allow view
of other components)

7

2. KM-320MWH (water-cooled)

Evaporator

Cleaning Valve

Bin Control
Thermostat

Spray Tubes

Expansion Valve

Control Switch

Water Supply Inlet

Hot Gas Valve

Water Regulator

Condenser

Float Switch

Water Pump

Drier

Compressor

Control Box
(shown transparent to allow view
of other components)

8

B. Controller Board

1. Solid-State Control

• A HOSHIZAKI exclusive solid-state control is employed in KM-320MAH and
KM-320MWH Modular Crescent Cubers.

• A printed circuit board (hereafter called "controller board") includes a stable and high
quality control system.

• All models are pretested and factory-adjusted.

2. Controller Board

CAUTION

1. Fragile, handle very carefully.

2. A controller 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 when 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 and float switch. K4 is
not connected.

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

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

Controller Board

Part Number Type

2A1410-01

Features of Control Products "E" Controller Board

a) Maximum Water Supply Period - 6 minutes

Water solenoid valve opening, in the defrost (harvest) cycle, is limited by the defrost
timer. The water valve cannot remain open longer than the maximum period. The water
valve can close in less than six minutes if the defrost cycle is completed.

b) Defrost Timer

The defrost cycle starts when the float switch opens and completes the freeze cycle.
But the defrost timer does not start counting until the thermistor senses 48°F (9°C) at
the evaporator outlet. The period from the end of the freeze cycle up to the point of the
thermistor’s sensing varies depending on the ambient and water temperatures.

HOS-001A (Control Products - 10 Pin)

9

c) High Temperature Safety - 127 ± 7°F (53 ± 4°C)

The temperature of the suction line in the refrigerant circuit is limited by the high
temperature safety.
During the defrost cycle the evaporator temperature rises. The thermistor senses
48°F (9°C) and starts the defrost timer. After the defrost timer counts down to zero,
the normal freeze cycle begins. If the evaporator temperature continues to rise, the
thermistor will sense the rise in temperature and at 127 ± 7°F (53 ± 4°C) the thermistor
operates the high temperature safety.
This high temperature safety shuts down the circuit and the icemaker automatically
stops.
This high temperature safety protects the unit from excessive temperature. The control
board will beep every 3 seconds. The white reset button on the control board must be
pressed with power on to reset the safety.

d) Low Water Safety

If the pump motor is operated without water, the mechanical seal can fail. To prevent
this type of failure, the controller board checks the position of the float switch at the end
of the initial one minute water fill cycle and at the end of each defrost cycle.
If the float switch is in the up position (electrical circuit closed), the controller board
changes to the ice making cycle. If the float switch is in the down position (electrical
circuit open), the controller board changes to a one minute water fill cycle before
starting the ice making cycle. This method allows for a low water safety shut down to
protect the water pump from mechanical seal failure.
For water-cooled model, if the water is shut off, the unit is protected by the high
pressure switch.

e) High Voltage Cut-out

The maximum allowable supply voltage of this icemaker is limited by the high voltage
cut-out.
If miswiring (especially on single phase 3 wire models) causes excessive voltage on
the controller board, the high voltage cut-out shuts down the circuit in 3 seconds and
the icemaker automatically stops. When the proper supply voltage is resumed, the
icemaker automatically starts running again. The control board will signal this problem
using 7 beeps every 3 seconds.

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 short beep occurs when the power switch is turned ON or
OFF.

10

The green LEDs 1-4 represent the corresponding relays and energize and sequence
5 seconds from initial startup as follows:

Sequence Step LED

Min. Max. Avg.

1 Minute Fill Cycle 4 60 seconds

Harvest Cycle 1, 4, and 2 2 minutes 20 minutes 3 to 5 minutes
Freeze Cycle 1 5 minutes 60 minutes 30 to 35 minutes

Reverse Pump Out 1, 3, and 2 10 seconds 20 seconds factory setting

{LED 1 – Comp; LED 2 - HGV/CFM; LED 3 – PM; LED 4 - WV}

The built in safeties shut down the unit and have alarms as follows:

No. of Beeps

(every 3 sec.)

1 High Evaporator Temp.

2 Defrost Backup Timer

Type of Alarm Notes

Check for defrost problem (stuck HGV
(temperature > 127°F)
(53°C)

(defrost > 20 min.)

or relay), hot water entering unit, stuck

headmaster, or shorted thermistor.

Orange LED marked H TIMER lights up.

Check for open thermistor, HGV not

opening, TXV leaking by, low charge, or

inefficient compressor.

Time LEDs are Lit

3 Freeze Backup Timer

(freeze > 60 min.)

To manually reset the above safeties, press the white alarm reset button with the
power supply on.

6 Low Voltage

(92Vac or less)

7 High Voltage

(control voltage
> 147Vac ±5%)

The output test switch "S3" provides a relay sequence test. With power OFF, place S3
ON and switch power to ICE. The correct lighting sequence should be none, 2, 3, 4, 1, &
4, normal sequence every 5 seconds. S3 should remain in the "OFF" position for normal
operation.

Yellow LED marked F TIMER lights up.

Check for F/S stuck closed (up), WV

leaking by, HGV leaking by, TXV not

feeding properly, low charge, or inefficient

compressor.

Red LED will turn off if voltage protection

operates.

The voltage safety automatically resets

when voltage is corrected.

11

The application switch located between relay X3 & X4 must be set to match the original
board application. Place this switch in the ALP position if there is no white wire supplied to
the K1 connector. If there is a white wire, place the switch in the C position. If this switch is
placed in the wrong position either the compressor contactor will remain energized with the
control switch OFF or the unit will not start.

The dip switches should be adjusted per the adjustment chart published in the Tech Specs
book. 7 & 8 must remain in the OFF position.

(Control Products HOS-001A Board)

12

3. Sequence

1st Cycle

1. Unit energized and control switch to "ICE"
position. Water supply cycle starts.

2. After 1 minute, defrost
cycle starts.

Water Valve

3. Thermistor reads 48°F (9°C).
Defrost timer starts counting.

Water Valve

Hot Gas Valve

Defrost
Cycle

Freeze
Cycle

Pump, Fan &
Line Valve

5. After the first 5 minutes in freeze cycle.
Ready to complete freeze cycle when float
switch circuit opens.

IMPORTANT

Board never accepts freeze completion signal
within the first 5 minutes in freeze cycle.

Defrost Timer

IMPORTANT

Water valve opening is
limited to 6 minutes.

4. Defrost timer stops counting.
Defrost cycle is completed and
freeze cycle starts.

IMPORTANT

1. Board never accepts defrost completion signal
within the first 2 minutes in defrost cycle.

2. Defrost cycle time is limited to 20 minutes even
if defrost timer does not stop counting.

13

2nd Cycle and after with pump drain

IMPORTANT

Freeze cycle time is limited by the freeze timer
factory setting even if the float switch does not
open.

1. Float switch opens and signals to complete
freeze cycle. Drain timer starts counting.

Drain Pump

Hot Gas Valve

2. Drain timer stops counting.
Pump drain is completed.

Defrost
Cycle

Water Valve

3. Thermistor reads 48°F (9°C).
Defrost timer starts counting.

Freeze
Cycle

Pump, Fan &
Line Valve

5. After the first 5 minutes in freeze cycle.
Ready to complete freeze cycle when float
switch circuit opens.

IMPORTANT

Board never accepts freeze completion signal
within the first 5 minutes in freeze cycle.

IMPORTANT

Water valve opening is

Defrost Timer

limited to 6 minutes.

4. Defrost timer stops counting.
Defrost cycle is completed and
freeze cycle starts.

IMPORTANT

1. Board never accepts defrost completion signal
within the first 2 minutes in defrost cycle.

2. Defrost cycle time is limited to 20 minutes even
if defrost timer does not stop counting.

14

2nd Cycle and after with no pump drain

IMPORTANT

Freeze cycle time is limited by the freeze timer
factory setting even if the float switch does not
open.

1. Float switch opens and signals to complete
freeze cycle.

Water Valve

Hot Gas Valve

Defrost
Cycle

Freeze
Cycle

2. Thermistor reads 48°F (9°C).
Defrost timer starts counting.

Defrost Timer

Pump, Fan &
Line Valve

4. After the first 5 minutes in freeze cycle.
Ready to complete freeze cycle when float
switch circuit opens.

IMPORTANT

Board never accepts freeze completion signal
within the first 5 minutes in freeze cycle.

IMPORTANT

Water valve opening is
limited to 6 minutes.

3. Defrost timer stops counting.
Defrost cycle is completed and
freeze cycle starts.

IMPORTANT

1. Board never accepts defrost completion signal
within the first 2 minutes in defrost cycle.

2. Defrost cycle time is limited to 20 minutes even
if defrost timer does not stop counting.

15