Hoshizaki KM300BAJ User Manual

Service Manual

Self-Contained Crescent Cuber

Models

KM-230BAJ

KM-300BAJ, BWJ

					hoshizakiamerica.com	Number: F111-1006
						Issued: 03-15-2018

WARNING

Only qualified service technicians should install and service the appliance. To obtain the name and phone number of your local Hoshizaki Certified 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 qualified 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: [phone]

Fax: [phone]

E-mail: [e-mail]

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.

	CONTENTS
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

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5.	Harvest Pump Timer.......................................................................................	35
6.	Freeze Timer...................................................................................................	35
7.	Pump-Out/Drain Selector................................................................................	36
8.	Harvest Promotion Control..............................................................................	36
9.	Refill 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. Specification 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 fire, follow basic precautions including the following:

•Only qualified 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 specifications. 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 fire.

•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 qualified 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 fire. 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, fire, 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 fingers 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 flammable substances near the appliance. They might catch fire.

•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 floor when moving the appliance to prevent damage to the floor.

•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 floor 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)
Rear	Front Cover
	Door
	Air Filter
	Louver
	Leg
	Side Panel (R)		Power Supply Cord
	Top Cover	Hot Gas Valve	Thermistor
	Evaporator	Drain Valve	Condenser
Fan Motor	Cleaning Valve
	Separator		Compressor
	Water Tank		Water Valve
	Expansion		Float Switch
Overflow Pipe	Valve		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

Overflow 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

Overflow Pipe

Drain Valve
Cleaning Valve	Separator

Water Valve

Pump Motor

Float Switch

8

Condenser

Water Valve

Spray Tube

		Fan

	Evaporator

Insulation Tube

Cleaning

Valve

Drain

Valve

9

Cube Guide

Water Tank

Drain

Refrigerant Circuit

Water Circuit

	High Pressure	.B
	Switch
		Water/Refrigeration 230BAJ-KM .1
Suction		Circuit
Line		Diagram
	Strainer

Discharge Line

			Water Valve
		Spray Tube	Water
			Supply
	Evaporator
			Cleaning
			Valve
			Drain
10			Valve
	Cube Guide

Water Tank
Pump	Float	Drain	Thermistor
Motor	Switch

Refrigerant Circuit

Water Circuit

	Condenser	High Pressure
		Switch

300BAJ-KM .2

Fan

Drier

Insulation Tube

Suction

Line

Strainer

Hot Gas

Valve

Discharge Line

Compressor

Access Valve

Expansion Valve

11

Water

Supply

Water Valve

Spray Tube

Water

Supply

Evaporator

Cleaning

Valve

Drain

Valve

Cube Guide

	Water Tank
	Pump	Float	Drain	Thermistor
	Motor	Switch

Refrigerant Circuit

Water Circuit

Water Regulating Drain

Valve

Water Condenser					High Pressure
					Switch

Drier

Insulation Tube

Suction

Line

Strainer

Hot Gas

Valve

Discharge Line

Compressor

Access Valve

Expansion Valve

300BWJ-KM .3

12

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 information below for details of each function.

DRAIN	Power is supplied to the pump and drain valve. This drains the water tank.
CIRCULATE	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.
WASH	Power is supplied to the pump and cleaning valve. This operation is used to circulate cleaner
	and sanitizer over both the insde and outside surfaces of the evaporator.

Chart Flow .1	Sequence .A	Sequence .II
	Operation of	Operation of
		Diagnosis Service and

PART NAME

HARVEST CYCLE

FREEZE CYCLE

HARVEST CYCLE

FREEZE CYCLE

HARVEST CYCLE

FREEZE CYCLE

HARVEST CYCLE

BIN FULL

HARVEST CYCLE

FREEZE CYCLE

HARVEST CYCLE

Thermistor senses 9°C after more

(INITIAL)

(INCLUDING DRAIN)

(AFTER BIN FULL)

than 8 min 30 sec in harvest cycle

POWER SWITCH

ON

OFF

10

10

10

10

9°C

THERMISTOR

1°C

COMPRESSOR

ON

OFF

FAN MOTOR

ON

*KM-230BAJ, 300BAJ

OFF

PUMP MOTOR

10 or 30sec

10 sec OFF,

50 sec ON

10 or 30sec

10 sec OFF,

50 sec ON

10 or 30sec

10 sec OFF,

50 sec ON

30 or 50sec

10 or 30sec

10 sec OFF,

50 sec ON

6min

ON

[KM-230BAJ] 30sec

OFF

[KM-300BAJ/BWJ] 10sec

3min

10 or 30sec

HOT GAS VALVE

ON

OFF

ON

Max 6 min

Max 6 min

Max 6 min

Max 6 min

Max 6 min

Max 6 min

WATER VALVE

13

OFF

5 sec

DRAIN VALVE

ON

10 sec

10 sec

OFF

CLEANING VALVE

ON

OFF

FLOAT SWITCH

ON

OFF

BIN CONTROL

ON

15 sec

90 sec

SWITCH

OFF

RELAY: X1

ON

(COMP)

OFF

BOARD

RELAY: X2

ON

(HV/FM)

OFF

CONTROLLER

RELAY: X3

ON

(PM)

OFF

RELAY: X4

ON

(WV)

OFF

RELAY: X6

ON

(DV)

OFF

HARVEST CYCLE

Thermistor senses 9°C after 6 min to 8 min 30 sec in harvest cycle

6min

60sec

Max 6 min

Chart Timing .2

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 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, 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 fill 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 first 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

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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 fill 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 flashes.

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 fill 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–float 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 qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire.

•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 flashing (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 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.

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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 efficiency, 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 float switch for freeze termination. During the first 5 minutes of freeze, confirm that the evaporator temperature drops. After the minimum freeze period, disconnect the float 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 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 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 satisfied 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 fill cycle.

17