Hoshizaki KML-631MWH, KML-631MAH, KML-451MWH, KML-451MAH, KML-351MWH User Manual

Service Manual

Modular Crescent Cuber with “G” Control Board

Model KMD-460MAH, MWH

KMD-530MAH, MWH, MRH KML-250MAH, MWH KML-351MAH, MWH KML-451MAH, MWH KML-631MAH, MWH, MRH

Number: 73205

hoshizakiamerica.com Issued: 5-7-2015

Revised: 10-27-2017

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.

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.

2

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..................................................................................................	5
I. Construction and Water/Refrigeration Circuit Diagram........................................................	7
A. Construction...................................................................................................................	7
1. Air-Cooled (MAH)......................................................................................................	7
2. Water-Cooled (MWH)...............................................................................................	8
3. Remote Air-Cooled (MRH).......................................................................................	9
B. Water/Refrigeration Circuit Diagram............................................................................	10
1. Air-Cooled Models (MAH).......................................................................................	10
2. Water-Cooled Models (MWH)..................................................................................	11
3. Remote Models (MRH)..........................................................................................	12
II. Sequence of Operation and Service Diagnosis................................................................	13
A. Sequence of Operation Flow Chart.............................................................................	13
1. "G" Control Board without Harvest Pump Timer Operation.....................................	13
2. "G" Control Board with Harvest Pump Timer Operation.........................................	14
3. Thermostatic and Mechanical Bin Control Shutdown Operation............................	15
B. Service Diagnosis........................................................................................................	16
1. "G" Control Board without Harvest Pump Timer Operation Diagnosis....................	17
2. "G" Control Board with Harvest Pump Timer Operation Diagnosis........................	23
C. Control Board Check....................................................................................................	30
D. Bin Control Check........................................................................................................	31
1. Thermostatic Bin Control Check ............................................................................	31
2. Mechanical Bin Control Check and Cleaning ........................................................	32
E. Float Switch Check and Cleaning................................................................................	34
1. Float Switch Check.................................................................................................	34
2. Float Switch Cleaning............................................................................................	35
F. Thermistor Check.........................................................................................................	36
G. Diagnostic Tables........................................................................................................	37
1. No Ice Production...................................................................................................	37
2. Freeze-Up..............................................................................................................	38
3. Low Ice Production.................................................................................................	39
III. Controls and Adjustments................................................................................................	41
A. Control Board Layout ..................................................................................................	42
B. LED Lights and Audible Alarm Safeties ......................................................................	43
C. Settings and Adjustments............................................................................................	44
1. Default Dip Switch Settings.....................................................................................	44
2. Harvest Timer (S4 dip switch 1 & 2).......................................................................	45
3. Pump-Out Timer (S4 dip switch 3 & 4)...................................................................	45
4. Pump-Out Frequency Control (S4 dip switch 5 & 6)...............................................	46
5. Harvest Pump Timer Operation (S4 dip switch 7)..................................................	46
6. Factory Use (S4 dip switch 8)................................................................................	46

3

7. Freeze Timer (S4 dip switch 9 & 10).......................................................................	47
8. Float Switch Selector (S5 dip switch 1)..................................................................	47
9. Refill Counter (S5 dip switch 2, 3, and 5), Program Selector (4)............................	47
D. Switches......................................................................................................................	48
1. Control Switch.........................................................................................................	48
2. Service Switch........................................................................................................	48
a) DRAIN..............................................................................................................	48
b) CIRCULATE.....................................................................................................	48
c) WASH...............................................................................................................	48
IV. Refrigeration Circuit and Component Service Information..............................................	49
A. Refrigeration Circuit Service Information.....................................................................	49
B. Component Service Information..................................................................................	52
C. Water Regulating Valve Adjustment (water-cooled model)...........................................	52
V. Maintenance.....................................................................................................................	53
VI. Preparing the Appliance for Periods of Non-Use.............................................................	54
VII. Disposal.........................................................................................................................	56
VIII. Technical Information....................................................................................................	57
A. Specification and Performance Data Sheets...............................................................	57
1. KMD-460MAH.........................................................................................................	57
2. KMD-460MWH.......................................................................................................	58
3. KMD-530MAH........................................................................................................	59
4. KMD-530MWH.......................................................................................................	60
5. KMD-530MRH........................................................................................................	61
6. KML-250MAH.........................................................................................................	62
7. KML-250MWH.........................................................................................................	63
8. KML-351MAH.........................................................................................................	64
9. KML-351MWH........................................................................................................	65
10. KML-451MAH.........................................................................................................	66
11. KML-451MWH........................................................................................................	67
12. KML-631MAH.........................................................................................................	68
13. KML-631MWH........................................................................................................	69
14. KML-631MRH........................................................................................................	70
B. Wiring Diagrams .........................................................................................................	71
1. Operation with Thermostatic Bin Control and without Harvest Pump Timer..........	71
a) KML-250M_H, KML-351MWH, KML-451M_H ..................................................	71
b) KML-631MAH, KML-631MWH...........................................................................	72
c) KML-631MRH....................................................................................................	73
2. Harvest Pump Timer Operation with Thermostatic or Mechanical Bin Control .......	74
a) KML-351MAH, KMD-460M_H, KMD-530M_H...................................................	74
b) KML-631MAH, KML-631MWH...........................................................................	75
c) KML-631MRH - C-1 to D-0 (No Crankcase Heater Relay)................................	76
d) KML-631MRH - D-1 and Later (Crankcase Heater Relay)................................	77

4

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 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 this appliance.

•The appliance must be installed in accordance with applicable national, state, and local codes and regulations.

•Electrical connection must be hard-wired and must meet national, state, and local electrical code requirements. Failure to meet these code requirements could result in death, electric shock, serious injury, fire, or damage.

•The icemaker 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 fuses, damage to existing

wiring, or component failure. This could lead to heat generation or fire.

•THE ICEMAKER MUST BE GROUNDED. Failure to properly ground the icemaker could result in death or serious injury.

•Move the control switch to the "OFF" position and turn off the power supply before servicing. Lockout/Tagout to prevent the power supply from being turned back on inadvertently.

•To reduce the risk of electric shock, do not touch the control switch or service switch with damp hands.

•Do not make any alterations to the unit. Alterations could result in electric shock, injury, fire, or damage to the unit.

•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.

5

WARNING, continued

•Children should be properly supervised around this appliance.

•Do not climb, stand, or hang on the appliance or allow children or animals to do so.

Serious injury could occur or the appliance could be damaged.

•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.

Additional Warning for Remote Models

•THE REMOTE CONDENSER UNIT MUST BE GROUNDED. The power supply and ground connection to the remote condenser unit are supplied from the icemaker. Failure to properly ground the remote condenser unit could result in death or serious injury.

•Move the icemaker control switch to the "OFF" position and turn off the power supply to the icemaker before servicing the remote condenser unit.

Lockout/Tagout to prevent the power supply from being turned back on inadvertently.

NOTICE

•Follow the instructions in this manual 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).

•Do not leave the icemaker on during extended periods of non-use, extended absences, or in sub-freezing temperatures. To properly prepare the icemaker for these occasions, follow the instructions in "VI. Preparing the Appliance for Periods of Non-Use."

•Do not place objects on top of the appliance.

•The dispenser unit/ice storage bin is for ice use only. Do not store anything else in the dispenser unit/ice storage bin.

6

I. Construction and Water/Refrigeration Circuit Diagram

A.Construction

1.Air-Cooled (MAH)

	Thermostatic
	Expansion Valve
	Cleaning Valve Drain Valve	Water Supply Inlet
Spray Tubes
Inlet Water Valve			Hot Gas Valve
Thermostatic
Bin Control
			Condenser
Pump Motor
Control Switch			Fan Motor
Service Switch			High-Pressure
Float Switch			Switch
Thermostatic Bin Control	Compressor	Liquid Line Valve	Drier
Bracket & Bulb Holder
	Control Box

Model Shown: KML-351MAH

Mechanical Bin Control

and Bracket

Model Shown: KMD-460MAH

7

2. Water-Cooled (MWH)

	Thermostatic	Spray Tubes Water Supply Inlet
	Expansion Valve
	Drain Valve	Water Regulating
		Valve

Cleaning Valve

Inlet Water Valve

Condenser

Thermostatic

Bin Control

High-Pressure

Switch

Control Box

Pump Motor
Float Switch		Drier
	Compressor	Hot Gas Valve
Thermostatic Bin Control	Control Switch
	Service Switch
Bracket & Bulb Holder
	Model Shown: KML-451MAH

Mechanical Bin Control
and Bracket	Model Shown: KMD-460MWH

8

3. Remote Air-Cooled (MRH)

Spray Tubes	Thermostatic
	Expansion Valve
Drain Valve	Water Supply Inlet
Cleaning Valve	Hot Gas Valve
Inlet Water Valve

Cleaning Valve
		Control Box
Control Switch		High-Pressure
Service Switch		Switch
Pump Motor		Reciever
Float Switch		Drier
Thermostatic		Liquid Line Valve
Bin Control
Thermostatic Bin Control	Compressor	Crankcase Heater

Bracket & Bulb Holder

Model Shown: KML-631MRH

Mechanical Bin Control

and Bracket

Model Shown: KMD-530MRH

9

B.Water/Refrigeration Circuit Diagram

1.Air-Cooled Models (MAH)

Spray Tubes	Condenser

Water Supply Inlet

Condenser

Inlet Water Valve Fan Motor High-Pressure

Switch

Drier

Cleaning Valve

Heat Exchanger

Drain Valve

Thermistor

Water Pump		Hot Gas Valve

Float Switch

Strainer

Compressor

Drain

Thermostatic Expansion Valve

10

2. Water-Cooled Models (MWH)

Water Regulating

Valve

Spray Tubes	Condenser

Water Supply Inlet

Inlet Water Valve

		Cleaning Valve	Drier			High-Pressure
						Switch
			Heat Exchanger
		Drain Valve
		Thermistor
						Hot Gas Valve
Water Pump
		Float Switch

Compressor Strainer

Drain

Thermostatic Expansion Valve

11

3. Remote Models (MRH)

Condenser

	Condenser	Headmaster
	Fan Motor

			High-Pressure
Spray Tubes			Switch
Water Supply Inlet
			Drier
Inlet Water Valve
Cleaning Valve	Receiver		Liquid Line
Heat Exchanger			Valve

Drain Valve

Thermistor

Hot Gas Valve

Water Pump

Float Switch

		Compressor	Strainer
Drain		Thermostatic Expansion Valve

12

"G" Control Board without Harvest Pump Timer Operation Flow Chart

Cycle

1. 1-Minute Fill

2. Harvest Cycle

3. Freeze Cycle

4. Pump-Out Cycle

Steps

Cycle

• Maximum inlet water valve time: 6 minutes

• Min. freeze time: 5 min.

• Every 1, 2, 5, or 10

• Max. freeze time: freeze timer

• Maximum harvest time: 20 minutes

cycles

setting

(S4 dip switch 5 & 6)

(S4 dip switch 9 & 10)

• Pump motor stops for

Thermistor in

1 to 3 min. harvest

5 min. minimum

2 sec., then energizes

FS in control

for 10/20 sec.

control

timer in control

freeze timer in

Startup

(S4 dip switch 1 & 2)

control

(S4 dip switch 3 & 4)

FS Check

FS closed

FS Check

FS closed

FS opens or

WV Energized

Comp energized

Thermistor temperature

Comp continues

freeze timer

Comp continues

terminates

FMR energized

reaches 48°F (9°C)

FMR continues

FMR continues

FS open

HGV energized

(3.9 kΩ or less) Harvest

FM energized

HGV energized

WV energized

timer starts (1 to 3 min.).

LLV energized

PM de-energizes for 2 sec.,

13

LLV de-energized

PM energized

then DV and PM energize

FS open

HGV de-energized

for 10/20 sec.

WV de-energized

FM de-energized

LLV de-energized

If FS is open, Comp stops and cycle returns to 1-min. fill.

Shutdown and Restart See "II.A.3. Thermostatic and Mechanical Bin Control Shutdown Operation"

Legend: Comp–compressor DV–drain valve

FM–fan motor FMR–fan motor-remote

FS–float switch HGV–hot gas valve LLV–liquid line valve

PM–pump motor WV–inlet water valve

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 motor and drain valve. This drains the water tank.
CIRCULATE	Power is supplied to the pump motor only. This can be used to circulate cleaner over the
	outside surface of the evaporator for extended periods of time.
WASH	Power is supplied to the pump motor and wash valve. This is used to circulate cleaner and
	sanitizer over both the inside and outside surfaces of the evaporator.

Operation Timer Pump Harvest without Board Control "G" 1.	Chart Flow Operation of Sequence .A	Diagnosis Service and Operation of Sequence .II

"G" Control Board with Harvest Pump Timer Operation Sequence Flow Chart

Cycle

1. 1-Minute

2. Harvest Cycle

3. Freeze Cycle

4. Pump-Out Cycle

Steps

Fill Cycle

• Max. inlet water valve time: 6 min. or the length of

• Min. freeze time: 5 min.

• Every 1, 2, 5, or 10

harvest minus 50 sec. (S4 dip switch 7), whichever is shorter.

• Max. freeze time: freeze timer setting

cycles

(S4 dip switch 9 & 10)

• Max. harvest time: 20 min.

(S4 dip switch 5 & 6)

Thermistor in

1 to 3-min. harvest timer in

• Pump motor stops for

2 sec., then energizes

control

control (S4 dip switch 1 & 2)

5-min. minimum

FS in control

for 10/20 sec.

Harvest Pump

freeze timer in

(S4 dip switch 3 & 4)

control

Timer

Startup

50 sec.

FS check

FS closed

FS check

FS closed

FS opens or

WV energized

Comp energized

PM energized

Comp continues

freeze timer

Comp continues

FMR continues

FMR energized

WV de-energized

FMR continues

terminates

HGV energized

HGV energized

Thermistor temperature reaches

FM energized

PM de-energizes for 2 sec.,

WV energized

LLV energized

FS open

48°F (9°C) (3.9 kΩ or less). Harvest

then DV and PM energize

PM energized

timer starts (1 to 3 min.).

for 10/20 sec.

HGV de-energized

FS open

FM de-energized

LLV de-energized

14

If FS is open, Comp stops and cycle returns to 1-min. fill.

Shutdown and Restart See "II.A.3. Thermostatic and Mechanical Bin Control Shutdown Operation"

Legend: Comp–compressor DV–drain valve

FM–fan motor FMR–fan motor-remote

FS–float switch HGV–hot gas valve LLV–liquid line valve

PM–pump motor WV–inlet water valve

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 motor and drain valve. This drains the water tank.
CIRCULATE	Power is supplied to the pump motor only. This can be used to circulate cleaner over the
	outside surface of the evaporator for extended periods of time.
WASH	Power is supplied to the pump motor and wash valve. This is used to circulate cleaner and
	sanitizer over both the inside and outside surfaces of the evaporator.

Operation Timer Pump Harvest with Board Control "G" .2

Shutdown Operation

Thermostatic Bin Control Shutdown Sequence Flow Chart

Shutdown						1. Bin Full		2. Icemaker Off		3. Ice Level Lowered
										No ice touching
and Restart						Within 10 sec.		All components
						after ice contacts		de-energized.		TBC bulb.
										Icemaker starts at
						TBC bulb, icemaker
										"1. 1-Minute Fill Cycle."
						shuts down.
TBC Operation											To 1. 1-Minute Fill Cycle
Ice contacts TBC bulb							TBC open		TBC closed
							All components		NOTE: "G" control board green "BC CLOSED" LED
							de-energized		on continuously when the K4 jumper is in place.

15

Mechanical Bin Control Shutdown Sequence Flow Chart

Shutdown

and Restart

MBC Operation

1.Bin Full Shutdown Delay:

•Fill Cycle–15 sec. after activation.

•Harvest Cycle–At the end of the harvest cycle, or up to 15 sec. into the

freeze cycle if activated at the end of the harvest cycle.

• Freeze Cycle–15 sec. after activation if activated at least 15 sec. before the 5-min. short cycle protection timer terminates. Otherwise, at the end of the next harvest cycle.

2. Icemaker Off	3. Ice Level Lowered
All components	Icemaker starts at
de-energized.	"1. 1-Minute Fill Cycle."

To 1. 1-Minute Fill Cycle

MBC open (MBC actuator paddle engaged)

Green "BC CLOSED" LED off

Yellow "BC OPEN" LED on

Legend:

MBC–mechanical bin control

TBC–themostatic bin control

Yellow "BC OPEN" LED continues. All components de energized.

MBC closed

(MBC actuator paddle disengaged) Green "BC CLOSED" LED on Yellow "BC OPEN" LED off

Operation Shutdown Control Bin Mechanical and Thermostatic .3

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 extreme 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 turn off the power supply.

•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 dispenser unit/ice storage bin.

•Make sure all food zones in the appliance and dispenser unit/ice storage bin are clean after service.

The diagnostic procedure is a sequence check that allows you to diagnose the electrical system and components. Before proceeding, check for correct installation, proper voltage per nameplate, and adequate water supply. Check CB using the steps in "II.C. Control Board Check." Check dip switch settings to assure that S4 dip switch 3, 4, 7, 8, 9, 10 and S5 dip switch 1 through 5 are in the factory default position. S4 dip switch 1, 2, 5, 6 are cleaning adjustments and the settings are flexible. For factory default settings, see "III.C.1. Default Dip Switch Settings."

Note: • When checking high voltage (115VAC), always choose a white (W) neutral wire to establish a good neutral connection.

•When checking voltage from the CB K1 connector (10 pin connector), pull CB K1 connector out slightly to allow room for multimeter test leads contact.

1)Turn off the power supply, then access the control box. Move the control switch to the

"OFF" position. Clear any ice from BC.

2)Check that the 115VAC 10A fuse is good.

16

1."G" Control Board without Harvest Pump Timer Operation Diagnosis

3)Power On: Turn on the power supply, then move the control switch to the "ICE" position.

A 5 sec. delay occurs. CB red "POWER OK" LED and green "BC CLOSED" LED turn on. If yellow "BC OPEN" LED is on (indicating a missing or loose jumper (4A4883G01)), check that the jumper is securely in place. Move ice away from TBC bulb. If yellow "BC OPEN" LED stays on, see "II.D.1. Thermostatic Bin Control (TBC) Check."

NOTICE! Do not adjust S4 dip switch 7 out of the factory default position. This dip

switch must be left in the factory default position or the appliance will not operate correctly.

Note: CB red "POWER" LED remains on unless the 10.5VAC power supply is interrupted (K2 connector).

a)Power On Diagnosis: If CB red "POWER OK" LED is off, confirm 10A fuse is good.

Check for 115VAC at control switch #2 (BR) to neutral (W) then at control switch

#3 (P) to neutral (W). If 115VAC is present on #2 (BR) and not on #3 (P), replace control switch. If 115VAC is present on control switch #3 (P), check for 115VAC at

HPS (P) to neutral (W) then HPS (BK) to neutral (W). If 115VAC is present at HPS (P) and not at HPS (BK), HPS is open. See HPS Diagnosis below. If 115VAC is present at HPS (BK), check for 10.5VAC at CB K2 #1 (R) to CB K2 #2 (R). If 10.5VAC is not present, check CT continuity. If open replace CT.

b)HPS Diagnosis: Check that the condenser coil is not clogged or restricted. Let refrigeration circuit pressures equalize. If HPS does not reset and pressures are equalized, replace HPS. If pressures are not equalized, reclaim refrigerant and diagnose refrigeration circuit restriction. Check that there are no restrictions in the refrigeration circuit.

Harvest Cycle: HGV, strainer, or check valve.

Freeze Cycle: FM, FMR, TXV, WRV, HM, LLV, strainer, check valve, drier, and damaged line set or fitting. On water-cooled models, confirm WRV opens in freeze cycle.

Confirm that the location meets installation requirements:

•The appliance is not intended for outdoor use. Normal operating ambient temperature should be within 45°F to 100°F (7°C to 38°C).

•Allow 6" (15 cm) clearance at rear, sides, and top for proper air circulation and ease of maintenance and/or service should they be required.

•The appliance should not be located in a corrosive environment.

17

4)1-Minute Fill Cycle – LED 4 is on. WV energizes. After 1 min., CB checks for a closed FS. If FS is closed, harvest cycle begins. If harvest cycle begins (Comp, HGV, and FMR energize), continue to step 5. If FS is open, WV remains energized through additional

1 min. fill cycles until water enters the water tank and FS closes (low water safety

protection during initial start up and at the end of each harvest).

Diagnosis: Check that water enters the water tank. If not, check that the water supply line shut off valve is open and screens or external filters are clear. Check for 115VAC at CB K1 #6 (O) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present, and WV does not energize, check for 115VAC at WV. If 115VAC is present,

check coil continuity. If open, replace WV. If the water tank fills, but the appliance fails to start harvest (Comp energized), check for open FS. See "II.E. Float Switch Check and Cleaning." If FS is closed and CB fails to start the harvest cycle after 1 min., replace

CB.

5)Initial Harvest Cycle – LEDs 1, 4, and 2 are on. WV continues. Comp, FMR, and HGV energize. CB monitors the warming of the evaporator via the thermistor located on the suction line. When the thermistor reaches 48°F (9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination over to the harvest timer (S4 dip switch 1 & 2). The harvest timer has settings of 60, 90, 120, and 180 sec. The pump out timer (S4 dip switch 3 & 4) acts in place of the harvest timer during cycles with a pump out (S4 dip switch 5 & 6). WV remains energized during harvest for a maximum of 6 min. or the length of harvest, whichever is shorter.

a)Comp Diagnosis: Check that evaporator is warming. If not, confirm that Comp energizes. If not, check for 115VAC at CB K1 #1 or #9 (V) to neutral (W). If 115VAC is not present, check for 115VAC at CB K1 #7 or #10 (BR) to neutral (W). If 115VAC is present at #7 or #10 (BR) and not at #1 or #9 (V), replace CB. If 115VAC is present, check for 115VAC at CR or MC solenoid. If 115VAC is present, confirm contacts are closed. If not, replace CR or MC. If CR or MC contacts are closed, check Comp external protector, Comp start and run capacitors, Comp start relay, and Comp motor winding.

b)HGV Diagnosis: If Comp is energized and evaporator is not warming, check that

HGV energizes and opens. Check for 115VAC at CB K1 #2 (P) to neutral (W).

If 115VAC is not present, replace CB. If 115VAC is present, check for 115VAC at HGV coil and check HGV coil continuity. Replace as needed.

c)LLV Diagnosis: Confirm that LLV is de-energized and closed (not bypassing).

If energized, replace CB. If de-energized and bypassing, replace LLV.

d)WRV Diagnosis: Confirm WRV is not leaking by.

18

e)Initial Harvest Cycle Termination Diagnosis: When the thermistor reaches

48°F (9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination over to the harvest timer (S4 dip switch 1 & 2). Check discharge line temperature. For a thermistor check, see "II.F. Thermistor Check." If 1-min. fill cycle starts after harvest

timer terminates, check that FS is clean and operating properly, see "II.E. Float Switch Check and Cleaning." If FS is closed, CB proceeds to the next cycle. If not, replace CB.

Note: The minimum total time allowed by CB for a complete harvest cycle is 2 min.

Maximum harvest time allowed is 20 min.

NOTICE! On models without harvest pump timer relays, S4 dip switch 7 must remain off. Otherwise, WV de-energizes the last 50 seconds of harvest.

6)Freeze Cycle – LED 1 is on. Comp and FMR continue. PM, FM, and LLV energize.

WV and HGV de energize. Appliance is held in freeze by a 5-min. short cycle protection timer. After 5-min. timer terminates and FS opens, freeze cycle terminates.

a)Freeze Cycle Diagnosis: Confirm Comp and FMR continue. Confirm that PM, FM, and LLV energize. Confirm WRV opens. Next, confirm WV and HGV de energize. During the first 5 min. of freeze, confirm evaporator is cooling. If not, confirm

WV de-energized (not leaking by), HGV de-energized (not bypassing), LLV and FM energize, TXV and HM operate correctly, WRV opens, Comp is efficient, and refrigerant charge is correct. See "VIII.A. Specification and Performance Data

Sheets."

b)Comp and FMR Diagnosis: If Comp and FMR de-energize once freeze begins, check that appliance has not shut off on HPS ("POWER OK" LED off). If so, check "3)b) HPS Diagnosis." If "POWER OK" LED is on, check for 115VAC at CB K1 #1 (V) or #9 (V) to neutral (W). If 115VAC is not present and LED 1 is on, replace CB.

If 115VAC is present, check for 115VAC at CR or MC coil. If 115VAC is present, check CR or MC coil and contact continuity. Replace as needed. If CR or MC is ok, check

Comp external overload, start relay, and start and run capacitors. Next, check Comp motor winding continuity. If Comp is energized but evaporator is not cooling, check for an inefficient Comp. See "VIII.A. Specification and Performance Data Sheets."

If Comp is energized but FMR is not, check for 115VAC at the FMR junction box. If 115VAC is not present, check icemaker wiring connections. If 115VAC is present, check for voltage at condenser unit. If 115VAC is not present, check field wiring connections. If 115VAC is present, check FMR capacitor, motor winding, and fan blade for binding.

c)WV and HGV Diagnosis: If WV is energized, check for 115VAC at CB K1 #6 (O) to neutral (W). If 115VAC is present after PM energizes, replace CB. If 115VAC is not present, replace WV (bypassing). If HGV did not de-energize, check for 115VAC at CB K1 #2 (P) to neutral (W). If 115VAC is present after PM energizes, replace CB. If 115VAC is not present, replace HGV (bypassing).

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d)PM Diagnosis: Confirm water is flowing over evaporator from PM and not WV. If PM de-energizes once freeze begins, check for 115VAC at CB K1 #4 (R) to neutral (W).

If 115VAC is not present, replace CB. If 115VAC is present and PM is de-energized, check for 115VAC at control switch #5 (Y) to neutral (W). If 115VAC is present at CB K1 #4 (R) and not at control switch #5 (Y), check control switch continuity between #5 (Y) and #6 (R). Replace as needed. If 115VAC is present at control switch #5 (Y) to neutral (W), check PM capacitor and motor winding continuity.

e)FM and LLV Diagnosis: If FM or LLV does not energize, check for 115VAC at CB

K1 #3 (BK) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present: For FM, check capacitor, motor winding, and blade for binding.

For LLV, check coil voltage and continuity.

f)Refrigerant Pressures, HM, and TXV Diagnosis: If evaporator is still not cooling, check refrigerant pressures. See "VIII.A. Specification and Performance Data

Sheets." Next, check HM operation. If refrigeration pressures are above HM setpoint and HM is bypassing, replace HM. Check TXV for proper operation. Remove TXV bulb and hold it in your hand, refrigerant low-side pressure should rise, place

TXV bulb in ice water, refrigerant low-side pressure should drop. A 10 to 15 pound pressure swing between warm and cold conditions indicate a good TXV. If a 10 to 15 pound swing is not present, replace TXV.

g)WRV Diagnosis: WRV is factory set and generally no adjustment is required.

If WRV fails to open in freeze, check for proper refrigerant pressures. See "VIII.A. Specification and Performance Data Sheets." If refrigerant pressures are correct and

WRV does not open, adjust or replace as needed. See "IV.C. Water Regulating Valve Adjustment (water cooled model)."

h)Freeze Termination Diagnosis: After 5 min. in freeze, disconnect CB K5 FS connector. 15 sec. later appliance should switch out of the freeze cycle (15 second delay after FS opens before terminating the freeze cycle). If appliance remains in freeze longer than 15 sec. after FS removed, replace CB. If appliance switches with FS removed but would previously not switch out of freeze with FS connected (long freeze - 3 beep alarm), see "II.E. Float Switch Check and Cleaning."

Note: Normal freeze cycle will last 20 to 40 min. depending on model and conditions.

Cycle times and pressures should follow performance data provided in this manual. See "VIII.A. Specification and Performance Data Sheets."

i)Short Freeze Cycle Diagnosis: Confirm water tank fills and overflows during 1 min. fill and harvest cycles. If not, check water supply filters, shut-off valve, WV screen. If water tank empties before 5 min. timer terminates and freeze cycle is short, check

that DV is not leaking by or energized (water flowing down the potable drain). If DV is leaking by, clean DV, replace as needed. If DV is energized during the freeze cycle, replace CB. If water tank is full, see "II.E. Float Switch Check and Cleaning" for erratic operating FS.

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7)Pump-Out Cycle – LEDs 1, 3, and 2 are on (10/20 second pump-out). Timing of the first pump-out is dependent on CB. The first pump-out is determined by S4 dip switch

5 & 6. See the table below.

	"G" Control Board Settings			1st Pump-Out
	S4 Dip Switch Setting		Pump-Out	"G" Control Board
	No. 5	No. 6	Frequency
	OFF	OFF	Every cycle	After 2nd freeze cycle
	ON	OFF	Every 2 cycles	After 3rd freeze cycle
	OFF	ON	Every 5 cycles	After 6th freeze cycle
	ON	ON	Every 10 cycles	After 11th freeze cycle

Comp and FMR continue, HGV energizes, LLV and FM de-energize. If S4 dip switch 3 & 4 are set to 3 off and 4 on, LED 4 turns on and WV energizes. PM stops for 2 sec., then PM and DV energize for 10/20 sec. depending on pump out timer (S4 dip switch 3 & 4) setting. When the pump out timer terminates, pump out is complete. The pumpout frequency control (S4 dip switch 5 & 6) is factory set, and generally no adjustment is required. However, the pump out frequency control can be set to have a pump out occur every cycle, or every 2, 5, or

10 cycles. For details, see "III.C.4. Pump Out Frequency Control (S4 dip switch 5 & 6)."

Pump-Out Diagnosis: In the freeze cycle before pump-out (see table above),

after 5 min. of freeze disconnect CB black K5 connector (FS connector) . Check that

PM stops and re-starts and that DV energizes and water is flowing down the drain through DV. If PM does not stop and re-start and DV does not energize, check that CB

LEDs 1, 3, and 2 are on. If not, replace CB. If LEDs 1, 3, and 2 are on and PM and DV do not energize, check for 115VAC at CB K1 #5 (DBU) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present, check for 115VAC at X10 relay #8 (DBU) to neutral (W). If 115VAC is present at X10 relay #8 (DBU) to neutral (W):

PM: Check for 115VAC at X10 relay #6 (BR) and X10 relay #4 (Y) to neutral (W).

If 115VAC is present at X10 relay #6 (BR) and not at X10 relay #4 (Y), replace X10 relay. If 115VAC is present at X10 relay #4 (Y), check PM capacitor, motor winding, and impeller for binding.

DV: Check for 115VAC from X10 relay #5 (DBU) and X10 relay #3 (GY) to neutral (W).

If 115VAC is present at X10 relay #5 (DBU) and not at X10 relay #3 (GY), replace

X10 relay. If 115VAC is present at X10 relay #3 (GY), check DV solenoid, replace as needed. Next, confirm that the drain line is not clogged.

Confirm FM and LLV de-energize. If FM or LLV are energized with LEDs 1, 3, and 2 on, replace CB.

8)Normal Harvest Cycle – Same as the initial harvest cycle. Return to step 5 above. Note: Appliance continues to cycle until TBC is satisfied or power is turned off. The

appliance always restarts at the 1-min. fill cycle.

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9) Shutdown

a) Thermostatic Bin Control (TBC):

When the appliance is running, hold ice in contact with the thermostatic bulb. BC switch opens within 10 sec., shutting down the appliance. TBC is factory set, and generally no adjustment is required. However, adjustment may be needed in some conditions, particularly at higher altitude locations.

Diagnosis: See "II.D.1. Thermostatic Bin Control Check." CB red K4 connector must have the jumper in place. When the jumper is in place, the green "BC CLOSED"

LED remains on. If the jumper is not in place, yellow "BC OPEN" LED turns on and the icemaker turns off and remains off until the jumper is replaced in its original position. IMPORTANT! CB red K4 connector jumper (4A4883G01) must be in place.

Legend: BC–bin control; CB–control board; Comp–compressor; CR–compressor relay; DV–drain valve; FM–fan motor; FMR–fan motor-remote; FS–float switch;

HGV–hot gas valve; HM–headmaster (C.P.R.); HPS–high-pressure switch;

LLV–liquid line valve; MC–magnetic contactor; PM–pump motor; TBC–thermostatic bin control; TXV–thermostatic expansion valve; WRV–water regulating valve; WV–inlet water valve

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2."G" Control Board with Harvest Pump Timer Operation Diagnosis

3)Power On: Turn on the power supply, then move the control switch to the "ICE" position.

A 5 sec. delay occurs. CB red "POWER OK" LED and green "BC CLOSED" LED turn on. If yellow "BC OPEN" LED is on (indicating a full bin):

KML-351MAH, KML-631M_H: If yellow "BC OPEN" LED is on (indicating a missing or loose jumper (4A4883G01)), check that the jumper is securely in place. Move ice away from TBC bulb. If yellow "BC OPEN" LED stays on, see "II.D.1. Thermostatic Bin Control

(TBC) Check."

KMD-460M_H, KMD-530M_H: Check MBC. Move ice away from MBC actuator paddle. If yellow "BC OPEN" LED stays on, see "II.D.2. Mechanical Bin Control (MBC) Check and Cleaning."

NOTICE! Do not adjust S4 dip switch 7 out of the factory default position. This dip switch must be left in the factory default position or the appliance will not operate correctly.

Note: CB red "POWER OK" LED remains on unless the 10.5VAC power supply is interrupted (K2 connector).

a)Power On Diagnosis: If CB red "POWER OK" LED is off, confirm 10A fuse is good. Check for 115VAC at control switch #2 (BR or BK) to neutral (W) then at control switch #3 (P) to neutral (W). If 115VAC is present on #2 (BR or BK) and not on

#3 (P), replace control switch. If 115VAC is present on control switch #3 (P), check for 115VAC at HPS (P) to neutral (W) then HPS (BK) to neutral (W). If 115VAC is present at HPS (P) and not at HPS (BK), HPS is open. See HPS Diagnosis below. If 115VAC is present at HPS (BK), check for 10.5VAC at CB K2 #1 (R) to CB K2 #2 (R).

If 10.5VAC is not present, check CT continuity. If open, replace CT.

b)HPS Diagnosis: Check that the condenser coil is not clogged or restricted. Let refrigeration circuit pressures equalize. If HPS does not reset and pressures are equalized, replace HPS. If pressures are not equalized, reclaim refrigerant and diagnose refrigeration circuit restriction. Check that there are no restrictions in the refrigeration circuit.

Harvest Cycle: HGV, strainer, or check valve.

Freeze Cycle: FM, FMR, TXV, WRV, HM, LLV, strainer, check valve, drier, and damaged line set or fitting. On water-cooled models, confirm WRV opens in freeze cycle.

Confirm that the location meets installation requirements:

•The appliance is not intended for outdoor use. Normal operating ambient temperature should be within 45°F to 100°F (7°C to 38°C).

•Allow 6" (15 cm) clearance at rear, sides, and top. KMD-460/530MAH require

12" (30 cm) clearance at right side.

• The appliance should not be located in a corrosive environment.

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4)1-Min. Fill Cycle – LED 4 is on. WV and X11 relay energize. After 1 min., CB checks for a closed FS. If FS is closed, the harvest cycle begins (X10, Comp, HGV,

FMR energize), Continue to step 5a. If FS is open, WV remains energized through additional 1-min. fill cycles until water enters the water tank and FS closes (low water

safety protection during initial start up and at the end of each harvest). Diagnosis: Check that water enters the water tank. If not, check that the water supply line shut-off valve is open and screens or external filters are clear. Check for 115VAC at CB K1 #6

(O) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present, and WV does not energize, check for 115VAC at WV. If 115VAC is present, check coil continuity. If open, replace WV. If the water tank fills, but the appliance fails to start harvest (Comp energized), check for open FS. See "II.E. Float Switch Check and Cleaning." If FS is closed and CB fails to start the harvest cycle after 1 min., replace CB.

5a) Initial Harvest Cycle – LEDs 1, 4, and 2 are on. WV and X11 relay continue. Comp,

FMR, HGV, and X10 relay energize. CB monitors the warming of the evaporator via the thermistor located on the suction line. When the thermistor reaches 48°F (9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination over to the harvest timer

(S4 dip switch 1 & 2). The harvest timer has settings of 60, 90, 120, and 180 sec. The pump out timer (S4 dip switch 3 & 4) acts in place of the harvest timer during cycles with a pump-out (S4 dip switch 5 & 6). WV and X11 relay are energized during harvest for a maximum of 6 min. or the length of harvest minus 50 sec., whichever is shorter. 50 sec. before harvest terminates, PM energizes. See step 5b below.

a)Comp Diagnosis: Check that evaporator is warming. If not, confirm that Comp energizes. If not, check for 115VAC at CB K1 #1 or #9 (V) to neutral (W). If 115VAC is not present, check for 115VAC at CB K1 #7 or #10 (BR or BK) to neutral (W).

If 115VAC is present at #7 or #10 (BR or BK) and not at #1 or #9 (V), replace CB.

If 115VAC is present, check for 115VAC at CR solenoid. If 115VAC is present, confirm contacts are closed. If not, replace CR. If CR contacts are closed, check Comp external overload, Comp start and run capacitors, Comp start relay, and Comp motor winding.

b)HGV Diagnosis: If Comp is energized and evaporator is not warming, check that

HGV energizes and opens. Check for 115VAC at CB K1 #2 (P) to neutral (W).

If 115VAC is not present, replace CB. If 115VAC is present, check for 115VAC at HGV coil and check HGV coil continuity. Replace as needed.

c)LLV Diagnosis: Confirm that LLV is de-energized and closed (not bypassing).

If energized, replace CB. If de-energized and bypassing, replace LLV.

d)WRV Diagnosis: Confirm WRV is not leaking by.

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