Hoshizaki DKM-500BAH User Manual

Hoshizaki America, Inc.

Hoshizaki

Crescent Cube Icemaker / Dispenser

Model
DKM-500BAH

“A Superior Degree

of Reliability”

www.hoshizaki.com

Service Manual

™

Number: 73138
Issued: 9-20-200

6

IMPORTANT

Only qualified service technicians should attempt to service or maintain this
unit. 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 unit.

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 30269

Attn: HOSHIZAKI Technical Support Department

Phone: [phone] Technical Service
[phone]
Fax: [phone]
[phone]
E-mail: [e-mail]

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 unit is serviced or
maintenance operations are performed. Only qualified service technicians should service
and maintain the unit. This manual should be made available to the technician prior to
service or maintenance.

CONTENTS

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

II. General Information ........................................................................................................... 6

A. Construction .................................................................................................................. 6

B. Sequence of Operation ................................................................................................. 7

1. One Minute Fill Cycle .............................................................................................. 7

2. Initial Harvest Cycle ................................................................................................ 7

3. Freeze Cycle ........................................................................................................... 7

4. Pump-Out Cycle ..................................................................................................... 7

5. Normal Harvest Cycle ............................................................................................ 7

C. Control Board ................................................................................................................ 9

1. Control Board Layout ............................................................................................. 10

2. Features ................................................................................................................ 11

a) Maximum Water Supply Period – 6 minutes ...................................................... 11

b) Harvest Backup Timer and Freeze Timer .......................................................... 11

c) High Temperature Safety ................................................................................... 11

d) Low Water Safety .............................................................................................. 11

e) High Voltage and Low Voltage Cut-outs ............................................................ 11

f) LED Lights and Audible Alarm Safeties .............................................................. 12

3. Controls and Adjustments ..................................................................................... 13

a) Default Dip Switch Settings ............................................................................... 13

b) Harvest Control – Thermistor ............................................................................ 13

c) Harvest Timer (dip switch 1 & 2) ........................................................................ 14

d) Pump-Out Timer (dip switch 3 & 4) ................................................................... 14

e) Pump-Out Frequency Control (dip switch 5 & 6) ............................................... 15

f) Freeze Timer (dip switch 9 & 10) ........................................................................ 15

g) Bin Control ........................................................................................................ 15

4. Bin Control Troubleshooting ................................................................................... 16

a) Machine Will Not Start ....................................................................................... 16

b) Machine Will Not Shut Off ................................................................................. 16

5. Control Board Check Procedure ............................................................................ 16

6. Control Board Replacement .................................................................................. 17

D. Switches ...................................................................................................................... 17

1. Control Switch ....................................................................................................... 17

2. Service Switch ....................................................................................................... 17

a) DRAIN ............................................................................................................... 17

b) CIRCULATE ...................................................................................................... 18

c) WASH ................................................................................................................ 18

3

III. Technical Information ...................................................................................................... 19

A. Water Circuit and Refrigeration Circuit ........................................................................ 19

B. Wiring Diagram ............................................................................................................ 20

C. Timing Chart ............................................................................................................... 21

D. Performance Data ....................................................................................................... 23

IV. Service Diagnosis ........................................................................................................... 24

A. 10-Minute Diagnostic Procedure ................................................................................ 24

B. Diagnostic Charts ........................................................................................................ 25

1. Ice Making ............................................................................................................. 25

a) No Ice Production .............................................................................................. 25

b) Evaporator is Frozen Up .................................................................................... 28

c) Low Ice Production ............................................................................................ 29

d) Abnormal Ice ..................................................................................................... 29

e) Other ................................................................................................................. 30

2. Dispensing ............................................................................................................. 30

V. Removal and Replacement of Components .................................................................... 32

A. Service for Refrigerant Lines ...................................................................................... 32

1. Refrigerant Recovery ............................................................................................. 32

2. Evacuation and Recharge (R-404A) ...................................................................... 32

B. Brazing ........................................................................................................................ 33

C. Removal and Replacement of Compressor ................................................................ 33

D. Removal and Replacement of Drier ............................................................................ 34

E. Removal and Replacement of Expansion Valve .......................................................... 35

F. Removal and Replacement of Hot Gas Valve .............................................................. 35

G. Removal and Replacement of Evaporator .................................................................. 36

H. Removal and Replacement of Condenser .................................................................. 37

I. Removal and Replacement of Thermistor .................................................................... 38

J. Removal and Replacement of Fan Motor .................................................................... 38

K. Removal and Replacement of Inlet Water Valve ......................................................... 39

L. Removal and Replacement of Pump Motor ................................................................. 39

M. Removal and Replacement of Spray Tubes ................................................................ 40

N. Removal and Replacement of Gear Motor ................................................................ 40

O. Removal and Replacement of Dispense Switch ......................................................... 41

P. Removal and Replacement of Solenoid ...................................................................... 41

VI. Cleaning and Maintenance Instructions ......................................................................... 42

A. Cleaning Instructions .................................................................................................. 42

1. Cleaning Procedure – Icemaker ............................................................................ 42

2. Sanitizing Procedure – Icemaker ........................................................................... 43

3. Cleaning Procedure – Bin ...................................................................................... 44

4. Sanitizing Procedure – Bin .................................................................................... 44

B. Maintenance Instructions ............................................................................................ 45

1. Exterior Panels ...................................................................................................... 45

2. Air Filters ............................................................................................................... 45

3. Condenser ............................................................................................................. 45

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

4

AC SUPPLY VOLTAGE 115/60/1
AMPERAGE 13.3 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 *466 (211) 448 (203) 420 (191)
Reference without *marks 80 453 (205) 425 (193) 395 (179)

90 448 (203) *406 (184) 376 (170)

100 390 (177) 399 (181) *348 (158)
SHAPE OF ICE Crescent Cube
ICE PRODUCTION PER CYCLE 7.2 lbs. (3.2 kg) 360 pcs.
APPROXIMATE STORAGE CAPACITY 200 lbs (91 Kg)
APPROXIMATE ICE DISPENSING SPEED 13 lbs/min (6 kg/min)
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 1150 (6.8) 1049 (5.4)
WATER gal./24HR (gal./100 lbs.) 66 (16.3) 110 (23.6)
EXTERIOR DIMENSIONS (WxDxH) 30" x 28" x 77" With 6" Flanged Legs
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
INTERIOR FINISH Polyethylene 1 pc. Mol

d

INSULATION Polyurethane Foam
WEIGHT Net 385 lbs. ( 175 kg ), Shipping 410 lbs. (186 kg)
CONNECTIONS - ELECTRIC Cord Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT x 2
CUBE CONTROL SYSTEM Float Switch
HARVESTING CONTROL SYSTEM Hot Gas and Water, Thermistor and Timer
ICE MAKING WATER CONTROL Timer Controlled. Overflow
COOLING WATER CONTROL N/A
BIN CONTROL SYSTEM Proximity Switch with Delay
COMPRESSOR Hermetic, Model RS55C2E-CAA-219
CONDENSER Air-cooled, Fin and tube type
EVAPORATOR Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R-404A, 2lbs (907g)
DESIGN PRESSURE High 467 PSIG, Low 170 PSIG
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

OPERATING CONDITIONS VOLTAGE RANGE 104 - 127 V

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

I. Specifications

A. DKM-500BAH

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

notice.

5

II. General Information

A. Construction

1. DKM-500BAH

Bin Cover

Inlet Water Valve

Expansion
Valve

Water Pump

Float Switch

Mechanical Bin
Control

Circulating Valve

Hot Gas Valve

Spray Tubes

Drain Valve

Water Supply
Inlet

Ice Cube Guide

Bin

Front Panel

Dispense Switch

Condenser

Dispense Switch
Connector

Condenser
Fan Motor

Drain Pan

Control
Switches

Agitator

Shutter

Chain

Solenoid
Assembly

Spout
Extension

Gear Motor
Assembly

Drier

Compressor

Strainer

Control Box

6

B. Sequence of Operation

The steps in the sequence are as outlined below. When power is supplied, a 5 second
delay occurs at startup. Note that the order of the LEDs from the outer edge of the board
is 1, 4, 3, 2.

1. One Minute Fill Cycle

LED 4 is on. WV opens and the fill period begins. After 1 minute, the board checks for a
closed F/S. If F/S is closed, the harvest cycle begins. If not, the unit will not start without
adequate water in the sump. This serves as a low water safety to protect the water pump.
WV will remain energized through additional 1 minute cycles until water enters the sump
and F/S closes.

2. Initial Harvest Cycle

LEDs 1, 4, and 2 are on. WV remains open, Comp energizes, HGV opens, and harvest
begins. As the evaporator warms, the thermistor located on the suction line checks for a
48°F (9°C) temperature. When 48°F (9°C) is reached, a 3.9 kΩ signal turns the harvest
over to the adjustable harvest timer which is factory set for normal conditions. The timer
has settings of 60, 90, 120, and 180 seconds (dip switch 1 & 2). When the harvest timer
completes its count down, the harvest cycle is complete and the freeze cycle starts. The
minimum total time allowed by the board for a complete harvest cycle is 2 minutes.

3. Freeze Cycle

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

4. Pump-Out Cycle

LEDs 1, 3, and 2 are on. Comp continues to run, HGV opens, and FMS de-energizes.
PM stops for 2 seconds. SR energizes, restarting PM and taking water from the sump
and forcing it to go through DV and down the drain. When the pump-out timer stops
counting, the pump out is complete.
Pump out always occurs on the 2nd harvest after startup. Then, depending on the control
board setting, pump out occurs every cycle, or every 2nd, 5th or 10th cycle (dip switch
5 & 6).

5. Normal Harvest Cycle

LEDs 1, 4, and 2 are on. Comp continues to run, HGV remains open and WV opens.
As the evaporator warms, the thermistor reaches 48°F (9°C). The control board then
receives the thermistor's 3.9 kΩ signal and starts the harvest timer. The water valve is
open during harvest for a maximum of 6 minutes or the length of harvest, whichever is
shorter. When the harvest timer completes its count down, the harvest cycle is complete
and the next freeze cycle starts.

Note: The unit continues to cycle through 3, 4 and 5 sequence until the bin control is

activated (within first 5 minutes of freeze) and shuts the unit down.

Legend:
switch; HGV–hot gas valve; PM–pump motor; SR–Service Relay; WV–inlet water
valve

Comp–compressor; DV–Drain Valve; FMS–self-contained fan motor; F/S–float

7

Cycle

4. Pump-Out

PM stops for 2 sec., SR

energizes, starting PM &

Comp continues

DV for 10/20 sec. each 1,

2, 5, or 10 cycles.

HGV energized

FMS de-energized

3. Freeze Cycle

2. Harvest Cycle

• Minimum freeze time: 5 minutes

• Maximum freeze time: freeze timer setting

• Bin control can only shut down unit within

F/S in

control

5 minute timer

in control

first 5 minutes of freeze cycle

1 to 3 minute timer

in control

F/S closed

F/S Check

F/S

Freeze cycle

operation turned

over to

Comp continues

HGV de-energized

WV de-energized

PM energized

Thermistor temp

reaches 48°F (9°C)

(3.9 kΩ or less)

Harvest timer starts

FMS energized

F/S open

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

control

Thermistor in

• Maximum inlet water valve time: 6 minutes

• Maximum harvest time: 20 minutes

DKM-500BAH Sequence Flow Chart and Component Operation

Fill Cycle

1. One Minute

F/S closed

F/S Check

Comp energized

WV Energized

HGV energized

WV continues

F/S open

Cycle Steps

"E" board will have

Initial startup always

5 second delay

begins here

8

Comp–compressor; DV–drain valve; FMS–self-contained fan motor; F/S–float switch;

Legend:

HGV–hot gas valve; PM–pump motor; SR–service relay; WV–inlet water valve

C. Control Board

• A HOSHIZAKI exclusive solid-state control is employed in the DKM-500BAH Crescent
Cube Icemaker / Dispenser.

• All units are pretested and factory-adjusted.

CAUTION

1. Fragile, handle very carefully.

2. A 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 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, float switch and
mechanical bin control.

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

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

9

1. Control Board Layout

Control Products "E" Control Board

Alarm Reset Switch

Backup Freeze
Timer LED

Backup Harvest
Timer LED

Alarm Buzzer

Dip Switch

Output Test Switch
(used to test relays on board)

Connector K3
Harvest Control
(thermistor)

Connector K4
Mechanical Bin
Control

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

Relay LEDs (4)
(indicate which
relays are energized
as listed below)

LED 2
Hot Gas Valve (HGV)
Self-Contained Fan
Motor (FMS) (FMS
off when LED on)

LED 3
Pump Motor (PM)
(on at pump out only)

LED 4
Water Valve (WV)

LED 1
Compressor (Comp)

Transformer
Connector

Microprocessor
(board revision level
indicated by last 2
digits on label)

Connector K5
Float Switch

Part Number

Connector K1

Pins #1 through #10
#1, 9 Magnetic Contactor
#2 Hot Gas Valve
#3 Self-Contained Fan Motor (FMS)
#4 Pump Motor (icemaking)
#5 Pump Motor (drain)
#6 Water Valve
#7, 10 Power (line, bin control)
#8 Open

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

Control Board

Part Number 2A1410-01 (factory); 2A1410-02 (service)

Type HOS-001A (Control Products - 10 Pin)

10

2. Features

a) Maximum Water Supply Period – 6 minutes

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

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 20 minutes to complete. The control board will signal this problem
using 2 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 specified to complete. The control board will signal this
problem using 3 beeps every 3 seconds. The time is factory set using dip switches 9 &

10.
The 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 127 ± 7°F (53 ± 4°C), the thermistor operates the
safety. This shuts down the circuit and the icemaker automatically stops.
The control board will signal this problem using 1 beep every 3 seconds. The 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 float switch at the end of the initial one
minute water fill cycle and at the end of each harvest cycle.
If the float switch is in the up position (electrical circuit closed), the control board changes
to the ice making cycle. If the float switch is in the down position (electrical circuit open),
the control board changes to additional one minute water fill cycles until water enters
the sump and the float switch closes. When the float switch closes, the control board
changes to the ice making cycle. The unit will not start without adequate water in the
sump. This serves as a low water safety to protect the water pump.

e) High Voltage and Low Voltage Cut-outs

The maximum and minimum allowable supply voltages of this icemaker are limited by the
high voltage and low voltage cut-outs.
If miswiring (especially on single phase 3 wire models) causes excessive voltage
(147Vac ±5% or more) on the control board, the high voltage cut-out shuts down the
circuit in 3 seconds and the icemaker automatically stops. The control board will signal
this problem using 7 beeps every 3 seconds.
The icemaker also automatically stops in cases of insufficient voltage (92Vac ±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.

11

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 OFF.
The green LEDs 1 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 1, 4, 3, 2.
For more information, see "II.B. Sequence of Operation."

Sequence Step LED

1 Minute Fill Cycle
Harvest Cycle

Freeze Cycle

Pump Out 1, 3, and 2 Comp, HGV,

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

No. of Beeps

(every 3 sec.)

1 High Evaporator Temp.

2 Harvest Backup Timer

4 WV 60 seconds
1, 4, and 2 WV, HGV,

1 Comp, PM,

Type of Alarm

(temperature > 127°F)
(53°C)

(harvest > 20 min. for two
cycles in a row)

Energized

Components

Comp

FMS

PM, SR, DV

Min. Max. Avg.

2 minutes 20 minutes 3 to 5 minutes

5 minutes freeze timer

10 seconds 20 seconds factory setting

Check for harvest problem (stuck HGV or
relay), hot water entering unit, 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 On

setting

Notes

30 to 35 minutes

3 Freeze Timer

(freeze > specified setting
for two cycles in a row)
Timer is factory set using
dip switches 9 & 10

4 Short Circuit

(between the K4 connec­tion on the control board
and the bin control)

5 Open Circuit

(between the K4 connec­tion on the control board
and the bin control)

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

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.

Resistor wire harness shorted. Check
and replace wire harness if necessary.

Resistor wire harness circuit open or
control board open. Check and replace
component if necessary.

12

No. of Beeps

(every 3 sec.)

Type of Alarm

Notes

Legend:

6 Low Voltage

(92Vac ±5% or less)

7 High Voltage

(147Vac ±5% or more)

Comp–compressor; DV–Drain Valve; FMS–self-contained fan motor; F/S–float

Red LED will turn off if voltage protection
operates.
The control voltage safeties automatically
reset when voltage is corrected.

switch; HGV–hot gas valve; PM–pump motor; SR–Service Relay; TXV–
thermostatic expansion valve; WV–inlet water valve

3. Controls and Adjustments

a) Default Dip Switch Settings

The dip switch is factory-adjusted to the following positions:

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

DKM-500BAH ON OFF OFF OFF ON ON ON OFF OFF ON

Freeze Timer (9 & 10)

Normally in the OFF position.

Mechanical Bin Control

Pump-Out Frequency Control (5 & 6)

Pump-Out Timer (3 & 4)

Harvest Timer (1 & 2)

b) Harvest Control – Thermistor

A thermistor (semiconductor) is used for a harvest control sensor. The resistance varies
depending on the suction line temperatures. The thermistor detects the temperature of
the evaporator outlet to start the harvest timer. No adjustment is required. If necessary,
check for resistance between thermistor leads, and visually check the thermistor
mounting, located on the suction line next to the evaporator outlet.

Temperature (°F) Temperature (°C) Resistance (kΩ)

0 -18 14.401
10 -12 10.613
32 0 6.000
50 10 3.871
70 21 2.474
90 32 1.633

13

Check a thermistor for resistance by using the following procedure:

1) Disconnect the connector K3 on the board.

2) Remove the thermistor. See "V.H. Removal and Replacement of Thermistor."

3) Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3
minutes.

4) Verify the temperature of the glass, then check for resistance between thermistor leads.
See the table above for temperature and resistance values. Normal reading is within

3.5 to 7 kΩ. Replace the thermistor if it exceeds the normal reading.

c) Harvest Timer (dip switch 1 & 2)

The harvest timer starts counting when the thermistor reads 48°F (9°C) at the
evaporator outlet.
No adjustment is required under normal use, as the harvest timer is adjusted to the
suitable position. However, a setting longer than the factory setting may be advised in
cases where the flush provided at harvest needs to be prolonged for extra cleaning.
Before changing this setting, call the HOSHIZAKI Technical Support Department at
1-800-233-1940 for recommendations. Keep in mind that setting the harvest timer to a
longer setting will decrease 24 hour production.

Dip Switch Setting Time

No. 1 No. 2

(seconds)

OFF OFF 60

ON OFF 90

OFF ON 120

ON ON 180

d) Pump-Out Timer (dip switch 3 & 4)

When a freeze cycle is completed, the pump motor stops, and the icemaker resumes
operation in 2 seconds. Then, during cycles when a pump out is called for, the pump
motor drains the water tank for the time determined by the pump-out timer. The pump­out timer also acts in place of the harvest timer during cycles with a pump out.
The pump-out timer is factory-adjusted, and no adjustment is required.

Dip Switch Setting

No. 3 No. 4

OFF OFF 10 150

ON OFF 10 180

OFF ON 10 120

ON ON 20 180

T1: Time to drain the water tank
T2: Harvest timer at pump out

Time (seconds)

T1

T2

Pump out always occurs on the 2nd harvest after startup. Then, depending on the pump­out frequency control setting (dip switch 5 & 6), pump out occurs every cycle, or every
2nd, 5th or 10th cycle.

14

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

The pump motor drains the water tank at the frequency set by the pump-out frequency
control.
The pump-out frequency control is factory-adjusted to drain the water tank every 10
cycles, and no adjustment is required. However, where water quality is bad and the
icemaker needs a pump drain more often, the pump-out frequency can be adjusted as
shown in the table below.

Dip Switch Setting

No. 5 No. 6

OFF OFF every cycle

ON OFF every 2 cycles

OFF ON every 5 cycles

ON ON every 10 cycles

f) Freeze Timer (dip switch 9 & 10)

Frequency

CAUTION

Adjust to proper specification, or the unit may not operate correctly.

The freeze timer setting determines the maximum allowed freeze time to prevent
possible freeze-up issues. Upon termination of freeze timer, machine initiates the harvest
cycle. After 2 consecutive timer terminations, machine will shut down, possibly indicating
a problem.
The freeze timer is factory adjusted and no adjustment is required.

Dip Switch Setting Time

No. 9 No. 10

OFF OFF 60

(minutes)

OFF ON 50

ON OFF 70
ON ON 60

g) Bin Control

CAUTION

Dip Switch No. 7 must be set to the ON position. If No. 7 is set to the OFF
position, the machine will run continuously, causing a freeze-up condition.

This machine uses a lever-actuated proximity switch (mechanical bin control) to control
the ice level in the storage bin. No adjustment is required. The bin control is factory­adjusted.

(1) Explanation of Operation

A resistor wire harness connects the bin control to the K4 connector on the control
board. When the bin control is calling for ice (proximity switch closed), a 7.9 KΩ reading
is sent to the control board to continue operation. When the bin control is activated in the
bin full position (proximity switch open), a 15.8 KΩ signal is sent to the control board to

15

shut down the unit. However, to prevent incomplete batches of ice from forming on the
evaporator, the control board will only shut down the machine within the first 5 minutes of
the freeze cycle. If ice pushes the lever in after the first five minutes of the freeze cycle,
the control board will allow the machine to complete the freeze cycle and the following
harvest cycle before shutting down the machine.
Dip switch number 7 must be in the ON position for the control board to receive input
from the bin control.

4. Bin Control Troubleshooting

a) Machine Will Not Start

1) Move dip switch no. 7 to the OFF position. If the machine starts up within a few
seconds, the bin control is the likely problem. If the machine does not start up, refer to
section "IV. Service Diagnosis" to verify that non-bin control related issues are resolved.

2) Check to make sure shipping tape has been removed and the wires are connected
properly.

3) Check to make sure no obstruction prevents the lever from moving to the bin empty
position.

4) Check proximity switch continuity to make sure it is not stuck open.

b) Machine Will Not Shut Off

1) Refer to Section "IV. Service Diagnosis" to verify that non-bin control related issues are
resolved.

2) Dip switch no. 7 should be in the ON position. If the switch is in the OFF position, the
control board will not receive input from the bin control.

3) Check to make sure no obstruction prevents the lever from moving to the bin full
position.

4) Push the lever in within the first 5 minutes of the freeze cycle. If the machine does not
shut off, check the resistance values of the resistor wire harness. You should read
approximately 15.8 K
the K4 connector on the control board when the lever is in the bin full position (proximity
switch open). If this reads approximately 7.9 KΩ, the resistors may be miswired or the
proximity switch may be stuck closed. Switch the black and white wires in the terminal
housing or order a replacement wire harness. If this does not resolve the problem,
replace the bin control assembly.

5. Control Board Check Procedure

Before replacing a control board that does not show a visible defect and that you suspect
is bad, always conduct the following check procedure. This procedure will help you verify
your diagnosis.

Ω between the black terminal and the red terminal that connect to

1) Check the dip switch settings to assure that #3, 4, 7, 8, 9, & 10 are in the factory default
position. Output test switch S3 should be OFF. Switches 1, 2, 5, & 6 are cleaning
adjustments and the settings are flexible.

2) Turn the control switch to ICE and check for proper control voltage. If the red LED is ON,
the control voltage is good. If the red LED is OFF, check the control transformer circuit.

16

3) Check the 115 volt input at the 10-pin connector. Check the brown wire at pin #10 to a
white neutral wire for 115 volts. (Always choose a white neutral wire to establish a good
neutral connection when checking voltages.) A jumper also feeds 115 volts into pin #7.
If no voltage is present, check the 115 volt supply circuit.

4) The output test switch S3 provides a relay sequence test. With the control switch in the
OFF position, place S3 ON and then move the control switch to the ICE position. The
correct lighting sequence should be none, 2, 3, 4, 1, and 4, normal sequence every 5
seconds. Components (e.g., the compressor) will cycle during the test. Note that the
order of the relays from the outer edge of the board is 1, 4, 3, 2.
Note: If the LEDs light in a different sequence or the 5–second interval does not occur,

the control board is bad and should be replaced.

5) After checking the sequence, place S3 back in the OFF position. The S3 switch must
remain in the OFF position during normal operation. This completes the output test and
the unit is now in the 1 minute fill cycle.

6. Control Board Replacement

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 to the factory default settings as outlined in this
manual. 8 must remain in the OFF position.

D. Switches

Two control switches are used to control operation. These switches are referred to as the
"control switch" and the "service switch" and are located on the control box.

1. Control Switch

The control switch has three positions: OFF for power off; ICE for icemaking, and
SERVICE to activate the service switch.

2. Service Switch

When the control switch is in the SERVICE position, the control switch supplies power
to the service switch and the machine is in service mode. The service switch has three
positions: DRAIN, CIRCULATE, and WASH. See the information below for details of each
function.

Note:

1. When the service switch is activated, power is supplied to the water pump in all
three positions.

2. When the control switch is in the OFF position or in the ICE position, the service
switch has no power and can be left in any position.

a) DRAIN

This model utilizes a pump-out drain system. When the service switch is active and
placed in the DRAIN position, power is supplied to the pump, service relay and drain
valve.

17

b) CIRCULATE

When the service switch is active and placed in the CIRCULATE position, power is
supplied to the pump only. This operation can be used to circulate cleaner for extended
periods of time over the outside surface of the evaporator.

c) WASH

This model utilizes a solenoid operated cleaning (bypass) valve. When the service
switch is active and placed in the WASH position, power is supplied to the pump and the
cleaning valve. This cleans both the inside and outside of the evaporator plate assembly.

18

III. Technical Information

A. Water Circuit and Refrigeration Circuit

1. DKM-500BAH

19

B. Wiring Diagram

1. DKM-500BAH

(12V)

* Pressure Switch

Cut-out 412.5 PSIG

Cut-in 327±21.3 PSIG

*

(Service

Relay)

20

C. Timing Chart

*1 The icemaker does not complete a defrost cycle in the first 2 or 3 minutes. See "II.C.3.

Controls and Adjustments."

21

*1 The pump motor waits for 2 seconds before starting a drain cycle. See "II.C.3. Controls

and Adjustments."

*2 The icemaker does not complete a defrost cycle in the first 2 or 3 minutes. See "II.C.3.

Controls and Adjustments."

22

70/21 466 211 448 203 420 191
80/27 453 205 425 193 395 179

90/32 448 203 406 184 376 170

lbs./day kg./da

y

100/38 390 177 399 181 348 158

70/21

80/27

90/32

watts 100/38

70/21 110 0.42

97 0.37 88 0.33

80/27 100 0.38 80 0.30 75 0.29

90/32 97 0.37 66 0.25 59 0.22

gal./day m3/day

100/38 144 0.55 65 0.24 53 0.20

70/21
80/27

90/32

min. 100/38

70/21

80/27
90/32

min. 100/38

70/21 262 18.4

282 19.8 305 21.5

80/27 277 19.5 308 21.7 329 23.2

90/32 282 19.8 330 23.2 353 24.8

PSIG kg/cm2G

100/38 284 20.0 335 23.6 374 26.3

70/21 56 3.9 57 4.0 58 4.1

80/27 57 4.0 58 4.1 60 4.2
90/32 57 4.0 59 4.2 61 4.3

PSIG kg/cm2G

100/38 57 4.0 60 4.2 62 4.4

SUCTION PRESSURE

HARVEST CYCLE TIME

HEAD PRESSURE

2.0

3.9

2.6

3.3

2.6

2.0

3.5

19

19

19
21

WATER TEMP. (ºF/ºC)

AMBIENT TEMP.

(ºF/ºC)

50/10 70/21 90/32

APPROXIMATE ICE
PRODUCTION PER 24 HR.

APPROXIMATE ELECTRIC
CONSUMPTION

APPROXIMATE WATER
CONSUMPTION PER 24 HR.

FREEZING CYCLE TIME

1100

1078

1117

1150

1155

1049

1071

1078

2.0

2.0

1103

1133

1170

1189

21
23

24

26

3.3

22

19

23

22

3.1

2.7

TOTAL HEAT OF REJECTION 8098 BTU/h [AT 90ºF (32ºC) / WT 70ºF (21ºC)]

D. Performance Data

1. DKM-500BAH

Note:

1. Pressure data is recorded at 5 minutes into freezing cycle. The data not in bold

2. We reserve the right to make changes in specifications and design without prior

should be used for reference only.

notice.

23

IV. Service Diagnosis

A. 10-Minute Diagnostic Procedure

The 10 minute check out procedure is basically a sequence check which can be used
at unit start-up or for system diagnosis. Using this check out procedure will allow you
to diagnose electrical system and component failures in approximately 10 minutes
under normal operating conditions of 70°F or warmer air and 50°F or warmer water
temperatures. Before conducting a 10 minute checkout, check for correct installation,
proper voltage per unit nameplate and adequate water supply. As you go through the
procedure, check to assure the components energize and de-energize correctly. If not,
those components and controls are suspect. Check for voltage at the 10-pin connector.
Note that an activated bin control may have the machine off (bin control will only shut
down the machine within the first 5 minutes of the freeze cycle).

1) Turn power OFF and access the control box.

2) Turn power ON and place the control switch in ICE position. A 5 second delay occurs.

3) One Minute Fill Cycle – The inlet water valve is energized. After 1 minute, the control
board checks the float switch. If the float switch is closed, the unit cycles to harvest. If
closed, continue to step 4. If the float switch is open, the unit repeats the 1 minute fill
cycle until water enters and the float switch closes (low water safety protection during
initial start up and at the end of each harvest). Diagnosis: If the water valve does not
open, check for no supply voltage at water valve terminals, bad coil, or plugged screen
or external filter (no water flow). If unit fails to start harvest, check for open float switch
or bad 1 minute timer in board.

4) Initial Harvest Cycle – Inlet water valve remains energized, contactor coil energizes
to start the compressor, and the hot gas valve energizes. The evaporator warms and
the thermistor senses 48°F (9°C). The control board then receives the thermistor's

3.9 kΩ signal and turns operation of harvest over to the harvest timer. The timer
completes counting (1 to 3 minutes). The unit then cycles to freeze. Diagnosis: Check
if compressor is running, hot gas valve is open, water valve still open. Average harvest
cycle at factory setting is 2 to 3 minutes. How long does initial harvest last? 1.5 minutes
after initial harvest begins, touch the compressor discharge line. Is it hot? If not check
refrigerant pressures and compressor operation. If it is hot, touch the inlet line to the
evaporator. Is it hot? If it is hot and the freeze cycle is not starting, check the harvest
timer adjustment, the thermistor for open circuit, the discharge line temperature,
compressor efficiency, and if the hot gas valve is fully open.

5) Freeze Cycle – Compressor remains energized, pump motor and fan motor energize.
The inlet water valve and hot gas valve de-energize. The unit is held in freeze by a
5 minute short cycle protection timer. After 5 minutes, the freeze cycle operation is
transferred to the float switch for freeze termination. During the first 5 minutes of freeze,
confirm that the evaporator temperature drops. After 7 minutes in freeze, remove the
black float switch lead from the K5 connector. The unit should immediately switch to the
pump-out cycle. Diagnosis: If the evaporator is not cold, check to see if the hot gas
valve is still open or if the expansion valve is not opening properly, if the water valve
is continuing to fill the reservoir, if there are improper unit pressures, or an inoperative
compressor. If the unit remains in freeze with the float switch removed, replace the
board.
Note: Normal freeze cycle will last 20 to 40 minutes depending on model and

24

conditions. Cycle times and pressures should follow performance data provided
in this manual.

6) Pump-Out Cycle (10/20 second pump out) – the compressor remains energized,
the hot gas valve energizes, the fan motor de-energizes, the pump motor stops for
2 seconds. The service relay energizes, restarting the pump motor and taking water
from the sump and forcing it to go through the drain valve and down the drain for 10/20
seconds. This removes contaminants from the water reservoir. Check for clear tubing at
the drain valve housing and check the unit drain for water flow. Diagnosis: If the pump
motor does not run, check the circuit, service relay and capacitor. Check for proper
voltage. If water does not pump out, remove the drain valve and check/clean the valve
assembly.

7) Normal Harvest Cycle – same as the initial harvest cycle – Return to step 4.
Note: Unit continues to cycle until bin control is satisfied or power is switched OFF. (The

pump out cycle can be adjusted to occur every cycle, or every 2, 5, or 10 cycles.
The factory default is every 10 cycles.) The unit always restarts at the 1 minute fill
cycle.

B. Diagnostic Charts

1. Ice Making

a) No Ice Production

Problem Possible Cause Remedy

[1] The icemaker will not

start.

a) Power Supply 1. OFF position. 1. Move to ON position.

2. Loose connection. 2. Tighten.

3. Bad contacts. 3. Check for continuity and
replace.

4. Voltage too high. 4. Check and get
recommended voltage.

b) Fuse (Inside fused

disconnect, if any)

c) Control Switch 1. OFF position. 1. Move to ICE position.

d) Bin Control

See the information
to the right and also
see "II.C.4. Bin Control
Troubleshooting."

1. Blown. 1. Check for short circuit and
replace.

2. Bad contacts. 2. Check for continuity and
replace.

1. Tripped with bin filled

with ice.

2. Bad contacts (stuck

open).

3. Resistor wire harness. 3. Check resistance. Should

1. Remove ice.

2. Check for continuity and
replace.

be approximately 7.9 KΩ
when calling for ice
(proximity switch closed).

e) High Pressure Control 1. Bad contacts. 1. Check for continuity and

replace.

2. Dirty air filter or
condenser.

3. Ambient temperature
too warm.

2. Clean.

3. Reduce temperature.

25

Problem Possible Cause Remedy

4. Refrigerant
overcharged.

5. Fan not operating. 5. See chart 1. a) [6]

4. Recharge.

[2] Water continues to

be supplied, and the
icemaker will not
start.

[3] Compressor will

not start or stops
operating.

6. Refrigerant line or
components plugged.

f) Transformer 1. Coil winding opened

or shorted.

g) Wiring to Control Board 1. Loose connections or

open.

h) Thermistor 1. Leads shorted or

opened and high
temperature or harvest
backup timer safety
operates. (1 beep or 2
beep alarm)

i) Hot Gas Valve 1. Continues to open

in freeze cycle and
freeze timer safety
operates. (3 beep
alarm)

j) Water Supply Line 1. Water supply off and

water supply cycle
does not finish.

k) Inlet Water Valve 1. Mesh filter or orifice

gets clogged and
water supply cycle
does not finish.

2. Coil winding opened. 2. Replace.

3. Wiring to water valve. 3. Check for loose

l) Control Board 1. Defective or in alarm. 1. See "II.C.5. Control Board

m)Control Switch 1. SERVICE position. 1. Move to ICE position.

2. Bad contacts. 2. Check and replace.

a) Float Switch 1. Connector

disconnected.

2. Leads opened or
defective switch.

3. Float does not move
freely.

b) Control Board 1. Defective. 1. See "II.C.5. Control Board

a) Magnetic Contactor 1. Bad contacts. 1. Check for continuity and

2. Coil winding opened. 2. Replace.

b) Start Capacitor or Run

Capacitor

1. Defective. 1. Replace.

6. Clean and replace drier.

1. Replace.

1. Check for continuity and
replace.

1. See "II.C.3. Controls and
Adjustments, b) Harvest
Control."

1. Check for hot gas valve
stuck open and replace.

1. Check and get
recommended pressure.

1. Clean.

connection or open, and
replace.

Check Procedure."

1. Place in position.

2. Check and replace.

3. Clean or replace.

Check Procedure."

replace.

26

Problem Possible Cause Remedy

[4] Water continues to

be supplied in freeze
cycle.

[5] No water comes from

spray tubes. Water
pump will not start, or
freeze cycle time is
too short.

c) Internal Overload

Protector Open (check
1 through 3 to the right
and d through f below)

d) Starter 1. Bad contacts. 1. Check and replace.

e) Compressor 1. Wiring to compressor. 1. Check for loose

f) Control Board 1. No power to contactor. 1. See "II.C.5. Control Board

a) Inlet Water Valve 1. Diaphragm does not

b) Control Board 1. Defective. 1. See "II.C.5. Control Board

a) Water Supply Line 1. Water pressure too

b) Inlet Water Valve 1. Dirty mesh filter or

c) Water System 1. Water leaks. 1. Check connections for

d) Pump Motor 1. Motor winding opened. 1. Replace.

1. Loose terminal. 1. Tighten or replace.

2. Voltage. 2. Check and correct.

3. Dirty condenser. 3. Clean.

2. Coil winding opened. 2. Replace.

connection or open, and
replace.

2. Defective. 2. Replace.

3. Protector tripped. 3. Reduce temperature.

Check Procedure."

1. Check for water leaks with

close.

low and water level in
water tank too low.

orifice and water level
in water tank too low.

2. Clogged. 2. Clean.

icemaker off.

Check Procedure."

1. Check and get
recommended pressure.

1. Clean.

water leaks, and replace.

[6] Fan motor will

not start, or is not
operating.

2. Bearing worn out. 2. Replace.

3. Wiring to pump motor. 3. Check for loose
connection or open, and
replace.

4. Defective capacitor. 4. Replace.

5. Defective or bound

impeller.

e) Control Board 1. Defective. 1. See "II.C.5. Control Board

a) Fan Motor 1. Motor winding opened. 1. Replace.

2. Bearing worn out. 2. Replace.

3. Wiring to fan motor. 3. Check for loose

4. Defective capacitor. 4. Replace.

5. Fan blade bound. 5. Check and replace.

5. Replace and clean.

Check Procedure."

connection or open, and
replace.

27

Problem Possible Cause Remedy

b) Control Board 1. Defective. 1. See "II.C.5. Control Board

Check Procedure."

[7] All components

run, but no ice is
produced.

a) Refrigerant 1. Undercharged. 1. Check for leaks and

recharge.

2. Air or moisture
trapped.

b) Compressor 1. Defective valve. 1. Replace.

c) Hot Gas Valve 1. Continues to open in

freeze cycle.

d) Inlet Water Valve 1. Water valve is wide

open during freeze.

2. Replace drier and
recharge.

1. Check and replace.

1. Check for water leaks with
icemaker off.

b) Evaporator is Frozen Up

Problem Possible Cause Remedy

[1]Freeze cycle time is

too long.

[2]All ice formed on

evaporator does not
fall into bin in harvest
cycle.

[3]Other a)Spray Tubes 1. Clogged. 1. Clean

a)Float Switch 1. Leads short-circuit or

defective switch.

2. Float does not move
freely.

b)Inlet Water Valve 1. Diaphragm does not

close.

c) Control Board 1. Defective. 1. See "II.C.5. Control Board

a)Evaporator 1. Scaled up. 1. Clean.

b)Water Supply Line 1. Water pressure too

low.

c) Water Filter System 1. Dirty/Restricted 1. Replace filter.

d)Inlet Water Valve 1. Dirty mesh filter or

orifice.

2. Diaphragm does not
close.

e) Ambient and/or water

temperature.

f) Thermistor 1. Out of position or

g)Control Board 1. Harvest timer is set

b)Water System 1. Dirty. 1. Clean.

c) Refrigerant 1. Undercharged. 1. Check for leaks and

1. Too cool. 1. Increase temperature.

loose attachment.

too short.

2. Defective. 2. See "II.C.5. Control Board

2. Out of position. 2. Place in position.

1. Check and replace.

2. Clean or replace.

1. Check for water leaks with
icemaker off.

Check Procedure."

1. Check and get
recommended pressure.

1. Clean.

2. Check for water leaks with
icemaker off.

1. See "V.H. Removal
and Replacement of
Thermistor."

1. Adjust longer, referring
to "II.C.3. Controls and
Adjustments, c) Harvest
Timer."

Check Procedure."

recharge.

28

Problem Possible Cause Remedy

d)Expansion Valve 1. Bulb out of position or

loose attachment.

2. Defective. 2. Replace.

e)Hot Gas Valve 1. Coil winding opened. 1. Replace.

2. Plunger does not
move.

3. Wiring to hot gas
valve.

f) Ice Cube Guide 1. Out of position and ice

trapped.

1. Place in position.

2. Replace.

3. Check for loose
connection or open, and
replace.

1. Place in position.

g)Water Supply Line 1. Too small; requires

3/8" OD line dedicated
per machine.

h)Water Filter 1. Flow rate too small. 1. Replace with filter that has

1. Increase water line size.

larger flow rate.

c) Low Ice Production

Problem Possible Cause Remedy

[1] Freeze cycle time is

long.

[2] Harvest cycle time is

long.

a) See chart 1. a) [3] and check dirty air filter or condenser, ambient or water

temperature, water pressure, and refrigerant charge.

b) See chart 1. b) [1] and check float switch, inlet water valve and control board.

c) Check pump, hot gas valve, expansion valve, refrigeration check valve, and

compressor.

a) See chart 1. b) [2] and check control board, thermistor, evaporator, ambient

and/or water temperature, water supply line, inlet water valve, and hot gas
valve.

d) Abnormal Ice

Problem Possible Cause Remedy

[1] Small cubes. a) Ice Cube Guide 1. Out of position.

Circulated water falls
into bin.

b) See chart 1. a) [5] and check water supply line, inlet water valve, water system,

pump motor, and control board.

c) Drain Valve 1. Dirty. 1. Clean.

1. Place in position.

[2] Cloudy or irregular

cubes.

a) See chart 1. b) [1] and 1. b) [3], and check float switch, inlet water valve, control

board, spray tubes, water system, refrigerant charge, and expansion valve.

b) Spray Guide 1. Dirty. 1. Clean.

c) Water Quality 1. High hardness or

contains impurities.

1. Install a water softener or
filter.

29

e) Other

Problem Possible Cause Remedy

[1] Icemaker will not stop

when bin is filled with
ice.

[2] Abnormal noise. a) Pump Motor 1. Bearings worn out. 1. Replace

[3] Ice in storage bin

often melts.

a) Bin Control See "II.C.4. Bin Control Troubleshooting."

b) Control Board 1. Defective. 1. See "II.C.5. Control Board

Check Procedure."

b) Fan Motor 1. Bearings worn out. 1. Replace

2. Fan blade deformed. 2. Replace fan blade.

3. Fan blade does not
move freely.

c) Compressor 1. Bearings worn out or

cylinder valve broken.

2. Mounting pad out of
position.

d) Refrigerant Lines 1. Rub or touch other

lines or surfaces.

a) Drain Line(s) 1. Plugged. 1. Clean.

b) Icemaker and Bin 1. Drains not run

separately.

c) Ice Cube Guide 1. Out of position.

Circulated water falls
into bin.

3. Replace.

1. Replace.

2. Reinstall.

1. Replace.

1. Separate the drain lines.

1. Place in position.

2. Dispensing

Problem Possible Cause Remedy

[1] No ice dispensed. a) Power Supply 1. OFF position. 1. Move to ON position.

2. Loose connection. 2. Tighten.

3. Bad contacts. 3. Check for continuity and
replace.

4. Voltage too high. 4. Check and get
recommended voltage.

b) Fuse (Inside Fused

Disconnect, if any)

c) Dispense Switch 1. Connector from front

d) Gear Motor 1. Thermal protector is

1. Blown. 1. Check for short circuit
and replace.

1. Connect.
panel not connected
to control box.

2. Bad contacts. 2. Check for continuity and
replace.

3. Loose connection. 3. Tighten.

1. Allow to cool.

tripped.

2. Gear motor winding

opened.

3. Bearing worn out. 3. Replace.

2. Replace.

30

Problem Possible Cause Remedy

4. Wiring to gear motor. 4. Check for loose
connection or open
circuit, and replace wiring
as needed.

5. Defective capacitor. 5. Replace.

6. Agitator rotates in

reverse direction.

e) Solenoid 1. Solenoid winding

open.

2. Wiring to solenoid. 2. Check for loose

3. Overload due to

loosening screws.

f) Mechanism 1. Chain out of position

or loose.

2. Corrosion. 2. Apply oil.

3. Key of sprocket is not

in position.

4. Bad alignment of

sprocket.

6. Check leads and reverse
the connections.

1. Replace

connection or open
circuit, and replace wiring
as needed.

3. After tightening, apply
thread sealant to the
parts.

1. Place in position or
tighten.

3. Place in position.

4. Readjust.

g) Ice Storage 1. No ice or little ice in

[2] Abnormal noise. a) Gear Motor or Gear

Head

b) Mechanism 1. Bad setting. 1. Apply oil and readjust.

c) Solenoid 1. Overload due to

5. Foreign matter
interrupting agitator.

storage bin.

2. Ice bridge or block
formed.

1. Bearing worn out. 1. Replace.

2. Grease leaks. 2. Supply grease and

2. Bad alignment of
sprocket.

3. Foreign matter
interrupting agitator.

loosening screws.

2. Foreign matter on
plunger.

5. Remove foreign matter.

1. Make ice.

2. Break with a poker.

replace O-ring.

2. Readjust.

3. Remove foreign matter.

1. After tightening, apply
thread sealant to the
parts.

2. Clean.

31

V. Removal and Replacement of Components

IMPORTANT

Ensure all components, fasteners and thumbscrews are securely in place after
the equipment is serviced.

IMPORTANT

1. The Polyol Ester (POE) oils used in R-404A units can absorb moisture
quickly. Therefore it is important to prevent moisture from entering the system
when replacing or servicing parts.

2. Always install a new filter drier every time the sealed refrigeration system is
opened.

3. Do not leave the system open for longer than 15 minutes when replacing or
servicing parts.

A. Service for Refrigerant Lines

1. Refrigerant Recovery

The icemaker unit is provided with two refrigerant access valves–one on the low-side
and one on the high-side line. Using proper refrigerant practices recover the refrigerant
from the access valves and store it in an approved container. Do not discharge the
refrigerant into the atmosphere.

2. Evacuation and Recharge (R-404A)

1) Attach charging hoses, a service manifold and a vacuum pump to the system. Be sure
to connect charging hoses to both high and low-side access valves.

IMPORTANT

The vacuum level and vacuum pump may be the same as those for current
refrigerants. However, the rubber hose and gauge manifold to be used for
evacuation and refrigerant charge should be exclusively for POE oils.

2) Turn on the vacuum pump. Never allow the oil in the vacuum pump to flow backward.

3) Allow the vacuum pump to pull down to a 29.9" Hg vacuum. Evacuating period depends
on pump capacity.

4) Close the low-side valve and high-side valve on the service manifold.

5) Disconnect the vacuum pump, and attach a refrigerant service cylinder to the high­side line. Remember to loosen the connection, and purge the air from the hose. See
the nameplate for the required refrigerant charge. Hoshizaki recommends only virgin
refrigerant or reclaimed refrigerant which meets ARI Standard No. 700-88 be used.

6) A liquid charge is recommended for charging an R-404A system. Invert the service
cylinder. Open the high-side, service manifold valve.

7) Allow the system to charge with liquid until the pressures balance.

32

8) If necessary, add any remaining charge to the system through the low-side. Use a
throttling valve or liquid dispensing device to add the remaining liquid charge through
the low-side access port with the unit running.

9) Close the two refrigerant access valves, and disconnect the hoses and service
manifold.

10) Cap the access valves to prevent a possible leak.

B. Brazing

DANGER

1. Refrigerant R-404A itself is not flammable at atmospheric pressure and
temperatures up to 176°F (80°C).

2. Refrigerant R-404A itself is not explosive or poisonous. However, when
exposed to high temperatures (open flames), R-404A can be decomposed to
form hydrofluoric acid and carbonyl fluoride both of which are hazardous.

3. Always recover the refrigerant and store it in an approved container. Do not
discharge the refrigerant into the atmosphere.

4. Do not use silver alloy or copper alloy containing arsenic.

5. Do not use R-404A as a mixture with pressurized air for leak testing.
Refrigerant leaks can be detected by charging the unit with a little refrigerant,
raising the pressure with nitrogen and using an electronic leak detector.

Note: Because the pipes in the evaporator case are specially coated to resist corrosion,

it is important to make connections outside the evaporator case when possible. If
it is necessary to braze inside the evaporator case, use sandpaper to remove the
coating from the brazing connections before unbrazing the components.

C. Removal and Replacement of Compressor

IMPORTANT

Always install a new drier every time the sealed refrigeration system is opened.

Note: When replacing a compressor with a defective winding, be sure to install the

new start capacitor and start relay supplied with the replacement compressor.
Due to the ability of the POE oil in the compressor to absorb moisture quickly,
the compressor must not be opened more than 15 minutes for replacement or
service. Do not mix lubricants of different compressors even if both are charged
with R-404A, except when they use the same lubricant.

1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

3) Recover the refrigerant and store it in an approved container.

33

4) Remove the terminal cover on the compressor, and disconnect the compressor wiring.

5) Remove the discharge and suction pipes using brazing equipment.

6) Remove the hold-down bolts, washers and rubber grommets.

7) Remove the compressor. Unpack the new compressor package.

8) Attach the rubber grommets of the prior compressor.

9) Place the compressor in position, and secure it using the bolts and washers.

10) Remove the drier, then place the new drier in position.

11) Remove plugs from the suction, discharge and process pipes.

12) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.

13) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.

14) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.

15) Connect the terminals, and replace the terminal cover in its correct position.

16) Replace the panels in their correct positions.

17) Turn on the power supply.

D. Removal and Replacement of Drier

IMPORTANT

Always install a new drier every time the sealed refrigeration system is opened.
Do not replace the drier until after all other repair or replacement has been
made.

1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

3) Recover the refrigerant and store it in an approved container.

4) Remove the drier.

5) Install the new drier with the arrow on the drier in the direction of the refrigerant flow.
Use nitrogen gas at a pressure of 3 to 4 PSIG when brazing the tubings.

6) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.

7) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.

8) Replace the panels in their correct positions.

9) Turn on the power supply.

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E. Removal and Replacement of Expansion Valve

IMPORTANT

Sometimes moisture in the refrigeration circuit exceeds the drier capacity and
freezes up at the expansion valve. Always install a new drier every time the
sealed refrigeration system is opened. Do not replace the drier until after all
other repair or replacement has been made.

1) Turn off the power.

2) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

3) Recover the refrigerant and store it in an approved container.

4) Remove the insulation and the expansion valve bulb on the suction line.

5) Remove the expansion valve cover, and disconnect the expansion valve using brazing
equipment.

6) Braze the new expansion valve with nitrogen gas flowing at the pressure of 3 to 4 PSIG.

WARNING

Always protect the valve body by using a damp cloth to prevent the valve from
overheating. Do not braze with the valve body exceeding 250°F (121°C).

7) Install the new drier.

8) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.

9) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.

10) Attach the expansion valve bulb to the suction line in the same location as the previous
bulb. The bulb should be at the 12 o'clock position on the tube. Be sure to secure the
bulb with the clamp and holder and to insulate it.

11) Place the new set of expansion valve covers in position.

12) Replace the panels in their correct positions.

13) Turn on the power supply.

F. Removal and Replacement of Hot Gas Valve

IMPORTANT

1. Always use a copper tube of the same diameter and length when replacing
the hot gas lines; otherwise the performance may be reduced.

2. Always install a new drier every time the sealed refrigeration system is

opened. Do not replace the drier until after all other repair or replacement
has been made.

3. Always replace the strainer when replacing the hot gas valve.

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1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

3) Recover the refrigerant and store it in an approved container.

4) Remove the screw and the solenoid.

5) Disconnect the hot gas valve using brazing equipment.

6) Install the new valve.

CAUTION

Always protect the valve body by using a damp cloth to prevent the valve from
overheating. Do not braze with the valve body exceeding 250°F (121°C).

7) Install the new drier.

8) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.

9) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.

10) Cut the leads of the solenoid allowing enough lead length to reconnect using closed
end connectors.

11) Connect the new solenoid leads.

12) Attach the solenoid to the valve body, and secure it with a screw.

13) Replace the panels in their correct positions.

14) Turn on the power supply.

G. Removal and Replacement of Evaporator

IMPORTANT

1. Always install a new drier every time the sealed refrigeration system is
opened. Do not replace the drier until after all other repairs or replacement
have been made.

2. Because the pipes in the evaporator section are specially coated to resist
corrosion, it is important to make the new evaporator inlet and outlet piping
connections outside the evaporator section as described below.

1) Turn off the power supply.

2) Remove the outer panels and the evaporator insulation panels. Be sure to disconnect
the dispense switch connector from the control box when removing the front panel.

3) Recover the refrigerant and store it in an approved container.

4) Remove the spray tubes and the insulations at the "U" shaped notch where the
refrigeration tubings go through the molded chassis.

5) Remove the insulation tube, and disconnect the evaporator inlet piping at the tee before
the expansion valve. Disconnect the evaporator outlet piping before the heat exchanger.

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6) Remove the pop rivets securing the evaporator, then lift out the evaporator.

7) Install the new evaporator.

8) Install the new drier.

9) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.

10) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.

11) Replace the removed parts in the reverse order of which they were removed.

12) Replace the evaporator insulation panels and the outer panels in their correct positions.

13) Turn on the power supply.

H. Removal and Replacement of Condenser

1) Turn off the power supply.

2) Remove the panels, including the rear panel next to the condenser. Be sure to
disconnect the dispense switch connector from the control box when removing the front
panel.

3) Recover the refrigerant and store it in an approved container.

4) Disconnect the fan motor wiring harness from the back of the control box. Remove the
four bolts securing the fan motor assembly to the floor of the machine, then remove the
assembly.

5) Disconnect the condenser inlet and outlet piping.

6) Remove the screws securing the condenser assembly, then remove the assembly.

7) Remove the shroud from the old condenser and attach it to the new condenser.

8) Install the new condenser.

9) Install the new drier.

10) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.

11) Evacuate the system, and charge it with refrigerant. See the nameplate for the required
refrigerant charge.

12) Replace the removed parts in the reverse order of which they were removed.

13) Replace the panels in their correct positions.

14) Turn on the power supply.

37

I. Removal and Replacement of Thermistor

IMPORTANT

1. Fragile, handle very carefully.

2. Always use a recommended sealant (High Thermal Conductive Type), Model
KE4560RTV manufactured by SHINETSU SILICONE, Part Code 60Y000-11,
or Part Code 4A0683-01 or equivalent.

3. Always use a recommended foam insulation (non-absorbent type) or
equivalent.

4. Do not shorten or cut the thermistor leads when installing it.

1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect
the dispense switch connector from the
control box when removing the front panel.

3) Remove the control box cover.

4) Disconnect the thermistor leads from the
K3 connector on the control board.

Thermistor Lead Cable Tie

5) Remove the plastic cable ties, foam
insulation, thermistor holder and thermistor.

6) Scrape away the old sealant on the
thermistor holder and the suction pipe.

7) Wipe off moisture or condensation on the
suction pipe.

8) Smoothly apply recommended sealant (KE4560RTV, Part Code 60Y000-11 or
4A0683-01) to the thermistor holder concave.

9) Attach the new thermistor to the suction pipe in the same position as the previous
thermistor. Be very careful to prevent damage to the leads. Secure it using the
thermistor holder and recommended foam insulation.

10) Secure the insulation using the plastic cable ties.

11) Connect the thermistor leads through the bushing of the control box to the K3
connector on the control board.
Note: Do not cut the leads of the thermistor while installing it.

12) Replace the control box cover and the panels in their correct positions.

13) Turn on the power supply.

Foam Insulation Thermistor Holder

J. Removal and Replacement of Fan Motor

Note: When replacing a fan motor with defective winding, it is recommended that a new

capacitor be installed.

1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

38

3) Disconnect the fan motor wiring harness from the back of the control box. Remove the
four bolts securing the fan motor assembly to the floor of the machine, then remove the
assembly.

4) Remove the fan motor from the fan motor bracket.

5) Remove the fan blade from the old fan motor and attach it to the new fan motor.

6) Install the new fan motor, and replace the removed parts in the reverse order of which
they were removed.

7) Replace the panels in their correct positions.

8) Turn on the power supply.

K. Removal and Replacement of Inlet Water Valve

1) Turn off the power supply.

2) Close the water supply line shut-off valve.

3) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

4) Loosen the fitting nut. Be careful not to lose the washer.

5) Remove the screws securing the valve to the bracket.

6) Remove the screws attaching the bracket to the machine wall, then remove the bracket
from the unit.

7) Remove the valve outlet tubing by releasing the clamp.

8) Disconnect the terminals from the water valve.

9) Install the new water valve, and replace the removed parts in the reverse order of which
they were removed. Make sure the washer is in place in the fitting nut.

10) Open the water supply line shut-off valve.

11) Turn on the power supply.

12) Check for leaks.

13) Replace the panels in their correct positions.

L. Removal and Replacement of Pump Motor

1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

3) Remove the three screws securing the float switch assembly, then remove the
assembly.

4) Remove the two screws securing the barrier directly over the pump, then remove the
barrier.

5) Remove the wiring connectors from the pump motor leads.

6) Remove the four screws securing the pump motor, disconnect the hoses, then remove
the pump motor.

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7) Install the new pump, and replace the removed parts in the reverse order of which they
were removed.

8) Turn on the power supply, and check for leaks.

9) Replace the panels in their correct positions.

M. Removal and Replacement of Spray Tubes

1) Turn off the power supply.

2) Remove the outer panels and the evaporator insulation panels. Be sure to disconnect
the dispense switch connector from the control box when removing the front panel.

3) Remove the rubber hoses from the spray tubes (water supply pipe).

4) Release the clamps, and disconnect the rubber hoses.

5) Remove the spray tubes.

6) Install the new spray tubes, and replace the removed parts in the reverse order of which
they were removed.

7) Replace the evaporator insulation panels and the outer panels in their correct positions.

8) Turn on the power supply.

N. Removal and Replacement of Gear Motor

1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect

the dispense switch connector from the
control box when removing the front panel.

3) Disconnect the gear motor wiring harness
from the back of the control box.

4) Loosen the adjustment bolt, then loosen
the four bolts securing Gear Motor Bracket
(B).

5) Slide Gear Motor Bracket (B) up to its
highest position and retighten.

6) Remove the chain.

7) Loosen the socket set screw securing the
sprocket, then use a gear puller to remove
the sprocket.

8) Remove the bushing from the barrier and
slide the gear motor wires free of the
barrier. Release the wires from the wire tie
on the barrier.

9) While supporting the gear motor and
barrier, remove the four bolts securing
them to Gear Motor Bracket (B). Carefully
remove the motor and barrier.

Lower sprocket
takes a 2.5 mm
allen wrench.

Bushing

Sprocket

40

Adjustment Bolt

Bolts

Chain

Bolts

Gear Motor
Bracket (B)

Sprocket

Gear Motor

Barrier

Gear Motor
Bracket (B)

Bolt

10) Install the new gear motor, assembling the removed parts in the reverse order of the
above procedure.
Note:

• When weight (2.2 Ib) is applied to the chain at the center, the displacement must be

0.31 to 0.51".

• Lubricant (Class SAE 20) must be applied to the chain using a cloth.

11) Replace the panels in their correct positions.

12) Turn on the power supply.

O. Removal and Replacement of Dispense Switch

1) Turn off the power supply.

2) Remove the front panel. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

3) Remove the dispense switch assembly.

4) Install a new dispense switch.

5) Replace the front panel in its correct position.

6) Turn on the power supply.

P. Removal and Replacement of Solenoid

1) Turn off the power supply.

2) Remove the panels. Be sure to disconnect the dispense switch connector from the
control box when removing the front panel.

3) Disconnect the connectors from the solenoid leads.

4) Remove the solenoid, and install a new solenoid.

5) Connect the connectors to the solenoid leads.

6) Replace the panels in their correct positions.

7) Turn on the power supply.

41

VI. Cleaning and Maintenance Instructions

IMPORTANT

Ensure all components, fasteners and thumbscrews are securely in place after
any maintenance or cleaning is done to the equipment.

A. Cleaning Instructions

To clean the machine, perform the cleaning and sanitizing procedures for the icemaker
and bin in the order in which they appear below.

WARNING

1. Hoshizaki recommends cleaning this unit at least once a year. More frequent
cleaning, however, may be required in some existing water conditions.

2. To prevent injury to individuals and damage to the icemaker, do not use
ammonia type cleaners.

3. Always wear liquid-proof gloves to prevent the cleaning and sanitizing
solutions from coming into contact with skin.

1. Cleaning Procedure – Icemaker

1) Dilute approximately 10.5 fl. oz. of recommended cleaner Hoshizaki "Scale Away" or
"LIME-A-WAY," (Economics Laboratory, Inc.) with 2 gallons of warm water.

2) Remove all ice from the evaporator and the bin.
Note: To remove cubes on the evaporator, turn off the power supply and turn it on

after 3 minutes. The defrost cycle starts and the cubes will be removed from the
evaporator.

3) Turn off the power supply.

4) Remove the front panel and disconnect the connector from the control box.

5) Move the control switch on the control box

Bin Control
Connector

to the SERVICE position. Then move the
service switch to the DRAIN position.

Thumbscrew

6) Replace the front panel in its correct position.

7) Turn on the power supply for 2 minutes.

8) Turn off the power supply.

Bin Cover

9) Remove the front panel.

10) Disconnect the bin control connector.
Remove the three thumbscrews securing
the bin cover, and remove the bin cover

Connector

with the bin control attached.

11) Pour the cleaning solution into the water tank.

Control
Box

12) Move the service switch to the WASH position.

13) Replace the front panel in its correct position.

Front
Panel

14) Turn on the power supply, and start the
washing process.

42

Bin

15) Turn off the power supply after 30 minutes.

16) Remove the front panel.

17) Move the service switch to the DRAIN position.

18) Replace the front panel in its correct position.

19) Turn on the power supply for 2 minutes.

20) Turn off the power supply.

21) Remove the front panel.

22) Move the control switch to the ICE position.

23) Replace the front panel in its correct position.

24) Turn on the power supply to fill the water tank with water.

25) Turn off the power supply after 3 minutes.

26) Remove the front panel.

27) Move the control switch to the SERVICE position. Then move the service switch to the
WASH position.

28) Replace the front panel in its correct position.

29) Turn on the power supply to rinse off the cleaning solution.

30) Turn off the power supply after 5 minutes.

31) Remove the front panel.

32) Move the service switch to the DRAIN position.

33) Replace the front panel in its correct position.

34) Turn on the power supply for 2 minutes.

35) Turn off the power supply.

36) Remove the front panel.

37) Repeat the above steps 22 through 36 three more times to rinse thoroughly, then
proceed to "2. Sanitizing Procedure – Icemaker".

2. Sanitizing Procedure – Icemaker

1) Dilute approximately 1.0 fl. oz. of a 5.25% sodium hypochlorite solution (chlorine
bleach) with 2 gallons of warm water.

2) Pour the sanitizing solution into the water tank.

3) Move the service switch to the WASH position.

4) Replace the front panel in its correct position.

5) Turn on the power supply, and start the sanitizing process.

6) Turn off the power supply after 15 minutes.

7) Remove the front panel.

8) Move the service switch to the DRAIN position.

9) Replace the front panel in its correct position.

43

10) Turn on the power supply for 2 minutes.

11) Turn off the power supply.

12) Remove the front panel.

13) Repeat steps 22 through 36 in "Cleaning Procedure – Icemaker" two times to rinse
thoroughly.

14) Move the control switch to the ICE position, then proceed to "3. Cleaning Procedure
– Bin".

3. Cleaning Procedure – Bin

1) Dilute approximately 5 fl. oz. of recommended cleaner Hoshizaki "Scale Away" or
"LIME-A-WAY," (Economics Laboratory, Inc.) with 1 gallon of warm water.

2) Make sure that the power supply is off.

3) Remove the grill and chute from the front panel.

4) Remove the shutter and spout extension as follows:

a. Remove the snap pin fitted to the shutter shaft. Shift the shaft to the left, pull out the

right side and slide out.

b. Remove the four thumbscrews securing the spout extension and remove the spout

extension.

5) Remove the two thumbscrews securing the bin control assembly to the bin cover. Note
the orientation of the stainless steel bracket, then remove the bin control and bracket
from the bin cover. Carefully remove the bin control paddle from the bin control body.

6) Scrub the inside of the bin, the agitator, the bin spout, the spout extension, the shutter,
the front panel spout, the grill, the chute, the bin cover, and the bin control assembly
using a nylon scouring pad, brushes and cleaning solution.

7) Rinse all parts thoroughly with clean water, then proceed to "4. Sanitizing Procedure
– Bin".

4. Sanitizing Procedure – Bin

Bin Control
Connector

Thumbscrew

Bin

1) Dilute approximately .5 fl. oz. of
a 5.25% sodium hypochlorite
solution (chlorine bleach) with
1 gallon of warm water.

2) Wash all parts from step 6 of
"Cleaning Procedure – Bin"
with the sanitizing solution.

3) Rinse all parts thoroughly
with clean water.

Bin Cover

Chute

Snap Pin

Connector

Agitator

Shutter

4) Reassemble all parts in the
reverse order of the removal
procedure.

5) Turn on the power supply.

6) Check for proper operation.

44

Front
Panel
Spout

Grill

Control
Box

Thumbscrew

Bin Spout

Spout
Extension

B. Maintenance Instructions

1. Exterior Panels

To keep the exterior clean, wipe occasionally with a clean and soft cloth. Use a damp
cloth containing a neutral cleaner to wipe off oil or dirt buildup.

2. Air Filters

The plastic mesh air filters (located behind the louvers on either side of the unit)
remove dirt and dust from the air, and keep the condenser from getting clogged. As
the filters get clogged, the icemaker's performance will be reduced. Check the filters at
least twice a month. When they are clogged, use warm water and a neutral cleaner to
wash the filters.

3. Condenser

Check the condenser once a year and clean if required by using a brush or vacuum
cleaner. More frequent cleaning may be required depending on the location of the
icemaker.

C. Preparing the Icemaker for Long Storage

IMPORTANT

When shutting off the icemaker for an extended time, drain the water tank
and remove the ice from the bin. The bin should be cleaned and dried. Drain
the icemaker to prevent damage to the water supply line at sub-freezing
temperatures, using a foot or hand pump. Shut off the icemaker until proper air
temperature is resumed.

1) Turn off the power supply.

2) Remove the front panel and disconnect the connector from the control box.

3) Move the control switch on the control box to the SERVICE position. Then move the
service switch to the DRAIN position.

4) Replace the front panel in its correct position.

5) Turn on the power supply for 2 minutes to allow the machine to drain.

6) Turn off the power supply.

7) Remove the front panel.

8) Move the control switch to the OFF position.

9) Close the water supply line shut-off valve.

10) Remove ice from the bin, then clean and dry the bin.

11) Reconnect the connector from the front panel to the control box and replace the front
panel in its correct position.

IMPORTANT

When the icemaker is not used for two or three days, move only the control
switch to the OFF position.

45