Hoshizaki KM300BAJ User Manual
Ser vice Manual
Self-Contained Crescent Cuber
Models
KM-230BAJ
KM-300BAJ, BWJ
hoshizakiamerica.com
Number: F111-1006
Issued: 03-15-2018
WARNING
Only qualied service technicians should install and service the appliance. To
obtain the name and phone number of your local Hoshizaki Certied Service
Representative, visit www.hoshizaki.com. No service should be undertaken until
the technician has thoroughly read this Service Manual. Failure to service and
maintain the appliance in accordance with this manual will adversely affect safety,
performance, component life, and warranty coverage and may result in costly water
damage. Proper installation is the responsibility of the installer. Product failure or
property damage due to improper installation is not covered under warranty.
Hoshizaki provides this manual primarily to assist qualied service technicians in the
maintenance and service of the product.
Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, send an e-mail message, or write to the Hoshizaki Technical
Support Department for assistance.
Phone: 1-800-233-1940; (770) 487-2331
Fax: 1-800-843-1056; (770) 487-3360
E-mail: techsupport@hoshizaki.com
618 Highway 74 South
Peachtree City, GA 30269
Attn: Hoshizaki Technical Support Department
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.
1
IMPORTANT
This manual should be read carefully before the appliance is serviced. Read the
warnings and guidelines contained in this manual carefully as they provide essential
information for the continued safe use, service, and maintenance of the appliance.
Retain this manual for any further reference that may be necessary.
Important Safety Information ..........................................................................................4
I. Construction and Water/Refrigeration Circuit Diagram ...............................................6
A. Construction ...........................................................................................................6
1. KM-230BAJ, KM-300BAJ .................................................................................6
2. KM-300BWJ .....................................................................................................7
3. Icemaking Compartment ..................................................................................8
B. Water/Refrigeration Circuit Diagram ......................................................................9
1. KM-230BAJ ......................................................................................................9
2. KM-300BAJ ....................................................................................................10
3. KM-300BWJ ................................................................................................... 11
II. Sequence of Operation and Service Diagnosis ........................................................12
A. Sequence of Operation ........................................................................................12
1. Flow Chart ......................................................................................................12
2. Timing Chart ...................................................................................................13
3. Details ............................................................................................................14
B. Service Diagnosis ................................................................................................16
C. Control Board Check ...........................................................................................18
D. Bin Control Check and Cleaning .........................................................................18
1. Bin Control Check ..........................................................................................19
2. Bin Control Cleaning ......................................................................................19
E. Float Switch Check and Cleaning ........................................................................21
1. Float Switch Check.........................................................................................21
2. Float Switch Cleaning ....................................................................................22
F. Thermistor Check .................................................................................................23
G. Diagnostic Tables ................................................................................................24
1. No Ice Production ...........................................................................................24
2. Freeze-Up ......................................................................................................27
3. Low Ice Production .........................................................................................28
4. Abnormal Ice ..................................................................................................28
5. Other ..............................................................................................................29
III. Controls and Adjustments........................................................................................30
A. Control Board Layout ...........................................................................................31
B. LED Lights and Audible Alarm Safeties ...............................................................32
C. Settings and Adjustments ....................................................................................33
1. Default Dip Switch Settings ............................................................................33
2. Harvest Timer .................................................................................................33
3. Pump-Out Timer .............................................................................................34
4. Pump-Out Frequency Control ........................................................................34
CONTENTS
2
5. Harvest Pump Timer.......................................................................................35
6. Freeze Timer ..................................................................................................35
7. Pump-Out/Drain Selector ...............................................................................36
8. Harvest Promotion Control .............................................................................36
9. Rell Counter .................................................................................................36
10. Harvest Completion Detection Control ...........................................................36
11. Overfreeze Detection Control .........................................................................37
12. Anti-Slush Control ...........................................................................................37
13. Control Board Replacement ...........................................................................38
D. Switches ..............................................................................................................38
1. Control Switch ................................................................................................38
2. Service Switch ................................................................................................38
IV. Refrigeration Circuit and Component Service Information ......................................40
A. Refrigeration Circuit Service Information ............................................................. 40
1. Refrigerant Recovery .....................................................................................41
2. Brazing ...........................................................................................................41
3. Evacuation and Recharge (R-404A) ..............................................................41
B. Component Service Information ..........................................................................42
C. Water Tank ...........................................................................................................43
D. Separator .............................................................................................................44
E. Door .....................................................................................................................45
F. Adjustment of Water Regulating Valve (Water-Cooled Model) .............................46
V. Maintenance .............................................................................................................47
A. Maintenance Schedule ........................................................................................47
VI. Preparing the Appliance for Periods of Non-Use ....................................................48
VII. Disposal .................................................................................................................49
VIII. Technical Information ............................................................................................50
A. Specication Data ................................................................................................50
1. KM-230BAJ ....................................................................................................50
2. KM-300BAJ ....................................................................................................51
3. KM-300BWJ ...................................................................................................52
B. Performance Data ................................................................................................53
1. KM-230BAJ ....................................................................................................53
2. KM-300BAJ ....................................................................................................54
3. KM-300BWJ ...................................................................................................55
C. Wiring Diagram ....................................................................................................56
3
Important Safety Information
Throughout this manual, notices appear to bring your attention to situations which could
result in death, serious injury, damage to the appliance, or damage to property.
WARNING Indicates a hazardous situation which could result in death or
serious injury.
NOTICE Indicates a situation which could result in damage to the
appliance or property.
IMPORTANT Indicates important information about the installation, use,
and care of the appliance.
WARNING
The appliance should be destined only to the use for which it has been expressly
conceived. Any other use should be considered improper and therefore dangerous.
The manufacturer cannot be held responsible for injury or damage resulting from
improper, incorrect, and unreasonable use. Failure to service and maintain the
appliance in accordance with this manual will adversely affect safety, performance,
component life, and warranty coverage and may result in costly water damage.
To reduce the risk of death, electric shock, serious injury, or re, follow basic
precautions including the following:
• Only qualied service technicians should install and service the appliance.
• The appliance must be installed in accordance with applicable national, state, and
local codes and regulations.
• The appliance requires an independent power supply of proper capacity. See
the nameplate for electrical specications. Failure to use an independent power
supply of proper capacity can result in a tripped breaker, blown fuse, damage to
existing wiring, or component failure. This could lead to heat generation or re.
• THE APPLIANCE MUST BE GROUNDED: The appliance is equipped with a
NEMA 5-15 three-prong grounding plug to reduce the risk of potential shock
hazards. It must be plugged into a properly grounded, independent 3-prong wall
outlet. If the outlet is a 2-prong outlet, it is your personal responsibility to have a
qualied electrician replace it with a properly grounded, independent 3-prong wall
outlet. Do not remove the ground prong from the plug and do not use an adapter
plug. Failure to properly ground the appliance could result in death or serious
injury.
• Do not use an extension cord.
• To reduce the risk of electric shock, do not touch the control switch, service switch,
or plug with damp hands. Make sure the control switch is in the "OFF" position
before plugging in or unplugging the appliance.
• Do not use an appliance with a damaged power cord. The power cord should not
be altered, jerked, bundled, weighed down, pinched, or tangled. Such actions
could result in electric shock or re. To unplug the appliance, be sure to pull the
plug, not the cord, and do not jerk the cord.
• Do not make any alterations to the appliance. Alterations could result in electric
shock, injury, re, or damage to the appliance.
4
WARNING, continued
• The appliance is not intended for use by persons (including children) with reduced
physical, sensory, or mental capabilities, or lack of experience and knowledge,
unless they have been given supervision or instruction concerning use of the
appliance by a person responsible for their safety.
• Young children should be properly supervised around the appliance.
• Do not climb, stand, or hang on the appliance or appliance door or allow children
or animals to do so. Serious injury could occur or the appliance could be
damaged.
• Be careful not to pinch ngers when opening and closing the door. Be careful
when opening and closing the door when children are in the area.
• Do not use combustible spray or place volatile or ammable substances near the
appliance. They might catch re.
• Keep the area around the appliance clean. Dirt, dust, or insects in the appliance
could cause harm to individuals or damage to the appliance.
NOTICE
• Protect the oor when moving the appliance to prevent damage to the oor.
• Follow the water supply, drain connection, and maintenance instructions carefully
to reduce the risk of costly water damage.
• In areas where water damage is a concern, install in a contained area with a oor
drain.
• Install the appliance in a location that stays above freezing. Normal operating
ambient temperature must be within 45°F to 100°F (7°C to 38°C).
• If water collects in the bin and will not drain, turn off the appliance and close the
water supply line shut-off valve. Locate and resolve the issue.
• Do not leave the appliance on during extended periods of non-use, extended
absences, or in sub-freezing temperatures. To properly prepare the appliance for
these occasions, follow the instructions in "VI. Preparing the Appliance for Periods
of Non-Use."
• Keep ventilation openings, in the appliance enclosure or in the built-in structure,
clear of obstruction.
• Do not place more than 33 lb. (15 kg) on the top panel.
• The storage bin is for ice use only. Do not store anything else in the storage bin.
5
I. Construction and Water/Refrigeration Circuit Diagram
A. Construction
1. KM-230BAJ, KM-300BAJ
Top Panel
Side Panel (L)
Front Cover
Rear Panel
Door
Air Filter
Louver
Leg
Side Panel (R) Power Supply Cord
Top Cover Hot Gas Valve Thermistor
Drain Valve
Evaporator Condenser
Fan Motor Cleaning Valve
Separator Compressor
Water Tank Water Valve
Expansion Float Switch
Valve
Overow Pipe Drier
Pump Motor
Control Switch
Service Switch
Control Box
Front View Rear View
Bin Control Switch
With Tank Removed
6
2. KM-300BWJ
Top Panel
Side Panel (L) Front Cover
Rear Panel
Door
Side Panel (R)
Louver Power Supply Cord
Leg
Top Cover Drain Valve Hot Gas Valve Thermistor
Cleaning Valve
Water Regulating
Evaporator Valve
Condenser
Separator
Water Tank
Compressor
Expansion
Valve Water Valve
Overow Pipe
Drier
Control Switch Float Switch
Service Switch
Control Box
Front View Rear View
Bin Control Switch
With Tank Removed
7
3. Icemaking Compartment
Spray Tube
Evaporator
Water Supply Pipe
Separator
Cube Guide
Water Tank
Overow Pipe
Drain Valve
Cleaning Valve Separator
Water Valve
Pump Motor
Float Switch
8
High Pressure
B. Water/Refrigeration Circuit Diagram
1. KM-230BAJ
Hot Gas
Strainer
Switch
Suction
Line
Valve
Discharge Line
Condenser
Water
Supply
Water Valve
Fan
Drier
Insulation Tube
Cleaning
Valve
Drain
Valve
Compressor
Thermistor
Drain
Float
Switch
Pump
Motor
Water Tank
ccess Valve
Refrigerant Circuit
Expansion Valve
Water Circuit
Spray Tube
Evaporator
9
Cube Guide
2. KM-300BAJ
High Pressure
Switch
Suction
Line
Hot Gas
Strainer
Valve
Discharge Line
Condenser
Water
Supply
Water Valve
Fan
Drier
Insulation Tube
Cleaning
Valve
Drain
Valve
Compressor
Thermistor
Drain
Float
Switch
Pump
Motor
Water Tank
Access Valve
Refrigerant Circuit
Expansion Valve
Water Circuit
Spray Tube
Evaporator
Cube Guide
10
3. KM-300BWJ
High Pressure
Switch
Drain
Suction
Line
Hot Gas
Strainer
Valve
Discharge Line
Water Regulating
Valve
Water Condenser
Water
Supply
Water
Supply
Water Valve
Drier
Compressor
Access Valve
Expansion Valve
Insulation Tube
Drain
Cleaning
Valve
Valve
Thermistor
Drain
Float
Switch
Refrigerant Circuit
Water Circuit
Pump
Water Tank
Motor
Spray Tube
Evaporator
Cube Guide
11
II. Sequence of Operation and Service Diagnosis
A. Sequence of Operation
1. Flow Chart
12
extended periods of time over the outside surface of the evaporator.
DRAIN Power is supplied to the pump and drain valve. This drains the water tank.
Components Energized when the Control Switch is in the “SERVICE” Position
When in the “SERVICE” position, the control switch supplies power to the service switch and the machine
is in service mode. The service switch has three positions: “DRAIN”, “CIRCULATE”, and “WASH”. See the
CIRCULATE Power is supplied to the pump only. This operation can be used to circulate cleaner for
information below for details of each function.
and sanitizer over both the insde and outside surfaces of the evaporator.
WASH Power is supplied to the pump and cleaning valve. This operation is used to circulate cleaner
n
2. Timing Chart
60sec
HARVEST CYCLE
Thermistor senses 9°C
after 6 min to 8 min 30 sec
in harvest cycle
HARVEST CYCLE
Thermistor senses 9°C after more
than 8 min 30 sec in harvest cycle
FREEZE CYCLE
HARVEST CYCLE
(AFTER BIN FULL)
BIN FULLPART NAME
FREEZE CYCLE HARVEST CYCLE
6min
10 or 30sec
3min
Max 6 min Max 6 mi
6min
10℃
10℃
10 sec OFF, 50 sec ON
Max 6 min
90 sec
10 sec
Max 6 min
15 sec
HARVEST CYCLE
(INCLUDING DRAIN)
FREEZE CYCLE HARVEST CYCLE FREEZE CYCLE
(INITIAL)
HARVEST CYCLE
10 sec
Max 6 min Max 6 min
10℃ 10℃
ON
9°C
OFF
POWER SWITCH
ON
1°C
THERMISTOR
10 sec OFF, 50 sec ON 10 sec OFF, 50 sec ON 10 sec OFF, 50 sec ON
Max 6 min
10 or 30sec 10 or 30sec 10 or 30sec 30 or 50sec 10 or 30sec
5 sec
ON
ON
ON
ON
ON
FAN MOTOR
OFF
*KM-230BAJ, 300BAJ
OFF
KM-230BAJ] 30sec
PUMP MOTOR
[
OFF
COMPRESSOR
ON
ON
ON
ON
OFF
OFF
OFF
OFF
DRAIN VALVE
WATER VALVE
HOT GAS VALVE
[KM-300BAJ/BWJ] 10sec
CLEANING VALVE
ON
OFF
OFF
SWITCH
BIN CONTROL
FLOAT SWITCH
ON
OFF
OFF
(COMP)
(HV/FM)
RELAY: X2
RELAY: X1
ON
ON
OFF
(PM)
RELAY: X3
OFF
OFF
(DV)
(WV)
RELAY: X6
RELAY: X4
CONTROLLER BOARD
13
3. Details
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 5, 6, 8, 4, 7.
a) One Minute Fill Cycle
LED 8 is on. WV opens and the ll period begins. After 1 minute, the board checks for
a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV will remain energized
through additional 1 minute cycles until water enters the sump and F/S closes. This
serves as a low water safety to protect the pump motor.
b) Initial Harvest Cycle
LEDs 5, 6, and 8 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 (S1 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. WV is open during harvest for a maximum of 6 minutes or the length of harvest
minus 0, 10, 30, or 50 seconds (adjustable by S1 dip switch 7 & 8), whichever is shorter.
LED 8 goes off when WV closes. PM energizes and runs for the last 0, 10, 30, or 50
seconds of harvest depending on S1 dip switch 7 & 8 setting. LED 7 comes on when
PM energizes. At the end of harvest, the control board checks the position of F/S and
proceeds to the freeze cycle if it is closed or calls for a 1-minute ll if it is open.
c) Freeze Cycle
LEDs 5 & 7 are on. Comp continues to run, PM and FMS energize, HGV closes and the
freeze cycle starts. For the rst 5 minutes after the thermistor temperature reaches 36°F
(2°C), the control board will not accept a signal from F/S. This minimum freeze period
acts as a short cycle protection. At the end of this period, F/S assumes control. As the
evaporator cools, the thermistor located on the suction line checks the temperature and
PM stops (see “II. A. 2. Timing Chart” for details). This is to prevent slushing. As ice
builds on the evaporator the water level in the sump lowers. The freeze continues until
F/S opens and terminates ice production.
d) Pump-Out Cycle
LEDs 4, 5, 6, and 7 are on. Comp continues to run, HGV opens, FMS de-energizes. PM
stops for 2 seconds, DV energizes, then PM restarts to take water from the sump and
force it through DV and down the drain. When the drain timer stops counting, the drain
is complete. The drain timer has settings of 10 and 20 seconds (S1 dip switch 3 & 4).
Pump-out cycle always occurs on the 2nd harvest after startup. Then, depending on
14
the control board setting, pump-out cycle occurs every cycle, or every 2nd, 5th, or 10th
cycle (S1 dip switch 5 & 6).
e) Normal Harvest Cycle
LEDs 5, 6, and 8 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. WV is open during
harvest for a maximum of 6 minutes or the length of harvest minus 0, 10, 30, or 50
seconds (adjustable by S1 dip switch 7 & 8), whichever is shorter. LED 8 goes off when
WV closes. PM energizes and runs for the last 0, 10, 30, or 50 seconds of harvest
depending on S1 dip switch 7 & 8 setting. LED 7 comes on when PM energizes. At the
end of harvest, the control board checks the position of F/S and proceeds to the freeze
cycle if it is closed or calls for a 1-minute ll if it is open.
The unit continues to cycle through c, d, and e sequence until the bin control is activated
and shuts the unit down. When the bin control is activated, the “POWER OK” LED
ashes.
f) Shutdown
When BC is activated (BC open), the “POWER OK” LED flashes. There is a delay
before the shutdown sequence begins. The delay varies depending on the cycle the
icemaker is in at the time of activation. For details, see the table below.
Cycle at Bin Control Activation Delay Before Shutdown Sequence Begins
Fill Cycle 15 seconds
Harvest Cycle 15 seconds after the next freeze cycle starts
Freeze Cycle 15 seconds if BC is activated between the beginning of
freeze and termination of the 5-minute short cycle protection
timer (timer starts when the thermistor temperature drops to
36°F (2°C) (5.5 kΩ or more)). After this time, the unit will not
shut down until the next harvest cycle is complete.
After the delay, all components de-energize. DV energizes after 2 seconds. PM
energizes after 2 seconds. PM takes water from the tank and forces it through DV and
down the drain. The water tank drains for a maximum of 5 minutes or until F/S opens.
DV and PM then de-energize. When BC closes again calling for ice, the unit starts at
the 1-minute ll cycle. There is a 90-second minimum off time before the icemaker can
restart.
Legend: BC–bin control; Comp–compressor; DV–drain valve; FMS–self-contained fan
motor; F/S–oat switch; HGV–hot gas valve; PM–pump motor; WV–inlet water
valve
15
B. Service Diagnosis
WARNING
• The appliance should be diagnosed and repaired only by qualied service
personnel to reduce the risk of death, electric shock, serious injury, or re.
• Risk of electric shock. Control switch in "OFF" position does not de-energize all
loads. Use extereme caution and exercise safe electrical practices.
• Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
• Before servicing the appliance, move the control switch to the “OFF“ position and
unplug the appliance.
• CHOKING HAZARD: Ensure all components, fasteners, and thumbscrews are
securely in place after the appliance is serviced. Make sure that none have fallen
into the ice storage bin.
• Make sure all food zones in the appliance and ice storage bin are clean after
service.
The diagnostic procedure is basically a sequence check which can be used at unit startup 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 (21°C) or warmer air and 50°F (10°C) 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.
1) Remove the louver. Move the control switch to the “OFF“ position, then unplug the
appliance. Access the control box. Clear any ice from the bin control actuator located
in the bin.
2) Plug in the appliance, then place the control switch in the “ICE” position. A 5 second
delay occurs. The “POWER OK” LED on the control board comes on. If the “POWER
OK” LED is ashing (indicating a full bin), check the bin control. See “II. D. 1 Bin
Control Check”.
3) One Minute Fill Cycle – The inlet water valve is energized. After 1 minute, the control
board checks the oat switch. If the oat switch is closed, the unit cycles to harvest.
If closed, continue to step 4. If the oat switch is open, the unit repeats the 1 minute
ll cycle until water enters and the oat 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 lter (no water ow). If unit fails to start harvest, check for
open oat switch or bad 1 minute timer in board.
16
4) Initial Harvest Cycle – The inlet water valve remains energized, contactor coil
energizes to start the compressor (and fan motor on a remote condenser unit),
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 efciency, and if the hot gas valve is fully open.
5) Freeze Cycle – The compressor remains energized, pump motor, (line valve if
applicable), and fan motor energize. The inlet water valve and hot gas valve deenergize. The unit is held in freeze by a 5 minute short cycle protection timer which
starts after the thermistor temperature reaches 36°F (2°C). After this period, the
freeze cycle operation is transferred to the oat switch for freeze termination. During
the rst 5 minutes of freeze, conrm that the evaporator temperature drops. After the
minimum freeze period, disconnect the oat switch at the 2-pin connector attached to
the red wires. 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 ll the
reservoir, if there are improper unit pressures or an inoperative compressor. If the
unit remains in freeze with the oat switch removed, replace the board.
Note: Normal freeze cycle will last 20 to 40 minutes depending on model and
conditions. Cycle times and pressures should follow performance data provided
in this manual.
6) Pump-Out Cycle – The compressor remains energized, the hot gas valve energizes,
the fan motor de-energizes. The drain valve and pump motor energize, allowing
water to drain from the tank for 10 seconds. This removes contaminants from the
water tank. Diagnosis: If the drain valve does not open, check the circuit. Check for
proper voltage. If water does not drain out, check and clean the tubing at the drain
valve and then check and clean the valve assembly.
7) Normal Harvest Cycle – same as the initial harvest cycle – Return to step 4.
8) Shutdown – See “II. D. 1 Bin Control Check”. Note that after a bin-control initiated
shutdown, there is a 90 second minimum off time.
Note: Unit continues to cycle until bin control is satised or power is turned 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
ll cycle.
17
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