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
hoshizakiamerica.com
Number: 73205
Issued: 5-7-2015
Revised: 10-27-2017
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.
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.
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. Rell 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. Specication 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 re, follow basic
precautions including the following:
• Only qualied 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, re, or damage.
• The icemaker 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 fuses, damage to existing
wiring, or component failure. This could lead to heat generation or re.
• 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, re, 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 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.
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 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).
• 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
Spray Tubes
Drain Valve
Water Supply Inlet
Inlet Water Valve
Thermostatic
Bin Control
Pump Motor
Control Switch
Service Switch
Float Switch
Thermostatic Bin Control
Bracket & Bulb Holder
Compressor
Control Box
Model Shown: KML-351MAH
Liquid Line Valve
Hot Gas Valve
Condenser
Fan Motor
High-Pressure
Switch
Drier
Model Shown: KMD-460MAH
7
Mechanical Bin Control
and Bracket
2. Water-Cooled (MWH)
Cleaning Valve
Inlet Water Valve
Thermostatic
Bin Control
Pump Motor
Thermostatic
Expansion Valve
Drain Valve
Float Switch
Spray Tubes
Water Supply Inlet
Water Regulating
Valve
Condenser
High-Pressure
Switch
Control Box
Drier
Thermostatic Bin Control
Bracket & Bulb Holder
Compressor
Control Switch
Service Switch
Model Shown: KML-451MAH
Hot Gas Valve
Mechanical Bin Control
and Bracket
8
Model Shown: KMD-460MWH
3. Remote Air-Cooled (MRH)
Cleaning Valve
Inlet Water Valve
Cleaning Valve
Control Switch
Service Switch
Pump Motor
Drain Valve
Spray Tubes
Thermostatic
Expansion Valve
Water Supply Inlet
Hot Gas Valve
Control Box
High-Pressure
Switch
Reciever
Float Switch
Thermostatic Bin Control
Bracket & Bulb Holder
Thermostatic
Bin Control
Compressor
Model Shown: KML-631MRH
Crankcase Heater
Drier
Liquid Line Valve
Mechanical Bin Control
and Bracket
9
Model Shown: KMD-530MRH
B. Water/Refrigeration Circuit Diagram
1. Air-Cooled Models (MAH)
Spray Tubes
Drain
Water Pump
Water Supply Inlet
Inlet Water Valve
Cleaning Valve
Drain Valve
Thermistor
Float Switch
Condenser
Condenser
Fan Motor
Drier
Heat Exchanger
Compressor
High-Pressure
Switch
Hot Gas Valve
Strainer
10
Thermostatic Expansion Valve
2. Water-Cooled Models (MWH)
Water Regulating
Val ve
Spray Tubes
Drain
Water Pump
Condenser
Water Supply Inlet
Inlet Water Valve
Cleaning Valve
Drain Valve
Thermistor
Float Switch
Drier
Heat Exchanger
Compressor
High-Pressure
Switch
Hot Gas Valve
Strainer
11
Thermostatic Expansion Valve
3. Remote Models (MRH)
Condenser
Spray Tubes
Condenser
Fan Motor
Drain Valve
Water Pump
Headmaster
Water Supply Inlet
Inlet Water Valve
Cleaning Valve
Heat Exchanger
Thermistor
High-Pressure
Switch
Drier
Receiver
Liquid Line
Val ve
Hot Gas Valve
Drain
Float Switch
12
Compressor
Thermostatic Expansion Valve
Strainer
II. Sequence of Operation and Service Diagnosis
A. Sequence of Operation Flow Chart
1. "G" Control Board without Harvest Pump Timer Operation
cycles
(S4 dip switch 5 & 6)
2 sec., then energizes
for 10/20 sec.
• Pump motor stops for
(S4 dip switch 3 & 4)
Comp continues
FMR continues
HGV energized
PM de-energizes for 2 sec.,
then DV and PM energize
for 10/20 sec.
FM de-energized
LLV de-energized
• Every 1, 2, 5, or 10
4. Pump-Out Cycle
• Min. freeze time: 5 min.
• Max. freeze time: freeze timer
FS in control
5 min. minimum
(S4 dip switch 9 & 10)
freeze timer in
1 to 3 min. harvest
timer in control
setting
FS opens or
freeze timer
control
FS closed
FS Check
(S4 dip switch 1 & 2)
terminates
Comp continues
FMR continues
Thermistor temperature
reaches 48°F (9°C)
FM energized
LLV energized
(3.9kΩ or less) Harvest
timer starts (1 to 3 min.).
PM energized
HGV de-energized
WV de-energized
FS open
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.
Power is supplied to the pump motor and drain valve. This drains the water tank.
Power is supplied to the pump motor only. This can be used to circulate cleaner over the
DRAIN
CIRCULATE
outside surface of the evaporator for extended periods of time.
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.
WASH
Thermistor in
• Maximum inlet water valve time: 6 minutes
• Maximum harvest time: 20 minutes
2. Harvest Cycle 3. Freeze Cycle
"G" Control Board without Harvest Pump Timer Operation Flow Chart
Cycle
1. 1-Minute Fill
Cycle
Steps
control
FS closed
Comp energized
FMR energized
HGV energized
WV energized
LLV de-energized
WV Energized
FS open
If FS is open, Comp stops and cycle returns to 1-min. ll.
Legend:
Comp–compressor
DV–drain valve
FM–fan motor
FMR–fan motor-remote
FS–oat switch
HGV–hot gas valve
LLV –liquid line valve
PM–pump motor
WV–inlet water valve
Shutdown and Restart See "II.A.3. Thermostatic and Mechanical Bin Control Shutdown Operation"
FS Check
Startup
13
2. "G" Control Board with Harvest Pump Timer Operation
cycles
(S4 dip switch 5 & 6)
2 sec., then energizes
for 10/20 sec.
4. Pump-Out Cycle
3. Freeze Cycle
• Every 1, 2, 5, or 10
• Min. freeze time: 5 min.
• Max. freeze time: freeze timer setting
(S4 dip switch 9 & 10)
• Pump motor stops for
(S4 dip switch 3 & 4)
FS in control
5-min. minimum
freeze timer in
control
Comp continues
FS opens or
FS closed
FMR continues
HGV energized
freeze timer
terminates
Comp continues
FMR continues
FM energized
PM de-energizes for 2 sec.,
LLV energized
then DV and PM energize
for 10/20 sec.
PM energized
HGV de-energized
FM de-energized
LLV de-energized
FS check
50 sec.
Harvest Pump
Timer
PM energized
WV de-energized
1 to 3-min. harvest timer in
control (S4 dip switch 1 & 2)
Thermistor temperature reaches
Thermistor in
control
• Max. inlet water valve time: 6 min. or the length of
harvest minus 50 sec. (S4 dip switch 7), whichever is shorter.
"G" Control Board with Harvest Pump Timer Operation Sequence Flow Chart
2. Harvest Cycle
1. 1-Minute
• Max. harvest time: 20 min.
Fill Cycle
FS closed
FS check
WV energized
Comp energized
FMR energized
HGV energized
48°F (9°C) (3.9 kΩ or less). Harvest
WV energized
FS open
FS open
timer starts (1 to 3 min.).
Power is supplied to the pump motor and drain valve. This drains the water tank.
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.
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.
DRAIN
CIRCULATE
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.
If FS is open, Comp stops and cycle returns to 1-min. ll.
WASH
Cycle
Steps
Startup
14
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–oat switch
HGV–hot gas valve
LLV–liquid line valve
PM–pump motor
WV–inlet water valve
3. Thermostatic and Mechanical Bin Control Shutdown Operation
Icemaker starts at
"1. 1-Minute Fill Cycle."
3. Ice Level Lowered
2. Icemaker Off
All components
de-energized.
To 1. 1-Minute Fill Cycle
MBC closed
(MBC actuator paddle disengaged)
Green "BC CLOSED" LED on
Yellow "BC OPEN" LED off
Shutdown Operation
To 1. 1-Minute Fill Cycle
Yellow "BC OPEN" LED continues. All
components de-energized.
3. Ice Level Lowered
No ice touching
TBC bulb.
Icemaker starts at
"1. 1-Minute Fill Cycle."
TBC closed
NOTE: "G" control board green "BC CLOSED" LED
on continuously when the K4 jumper is in place.
2. Icemaker Off
All components
de-energized.
Thermostatic Bin Control Shutdown Sequence Flow Chart
1. Bin Full
Within 10 sec.
after ice contacts
TBC bulb, icemaker
shuts down.
TBC open
All components
de-energized
Mechanical Bin Control Shutdown Sequence Flow Chart
freeze cycle if activated at the end of the harvest cycle.
the 5-min. short cycle protection timer terminates.
• Harvest Cycle–At the end of the harvest cycle, or up to 15 sec. into the
• Freeze Cycle–15 sec. after activation if activated at least 15 sec. before
Otherwise, at the end of the next harvest cycle.
MBC open (MBC actuator paddle engaged)
Green "BC CLOSED" LED off
Yellow "BC OPEN" LED on
1. Bin Full
Shutdown Delay:
• Fill Cycle–15 sec. after activation.
Shutdown
Ice contacts TBC bulb
Shutdown
and Restart
TBC Operation
and Restart
Legend:
MBC–mechanical bin control
MBC Operation
TBC–themostatic bin control
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 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 exible. 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
CBK1connector 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" LEDturn
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, conrm 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). If115VAC 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. Ifopen 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 tting. On water-cooled models, conrm WRV opens in freeze
cycle.
Conrm 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. ll 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 lters 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. Ifopen, replace WV. If the water tank lls, 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 180sec. Thepump-out timer (S4dip
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 6min. or the
length of harvest, whichever is shorter.
a) Comp Diagnosis: Check that evaporator is warming. Ifnot, conrm 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). If115VAC 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, conrm 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).
If115VAC 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: Conrm that LLV is de-energized and closed (not bypassing).
Ifenergized, replace CB. If de-energized and bypassing, replace LLV.
d) WRV Diagnosis: Conrm WRV is not leaking by.
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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. ll 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. Ifnot,
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, S4dip switch 7 must
remain off. Otherwise, WV de-energizes the last 50seconds of harvest.
6) Freeze Cycle – LED 1 is on. Comp and FMR continue. PM, FM, and LLVenergize.
WV and HGV de-energize. Appliance is held in freeze by a 5-min. short cycle protection
timer. After 5-min. timer terminates and FSopens, freeze cycle terminates.
a) Freeze Cycle Diagnosis: Conrm Comp and FMR continue. Conrm that PM, FM,
and LLV energize. Conrm WRV opens. Next, conrm WV and HGV de-energize.
During the rst 5 min. of freeze, conrm evaporator is cooling. If not, conrm
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. Specication 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.
If115VAC 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. Specication and Performance Data Sheets."
If Comp is energized but FMR is not, check for 115VAC at the FMR junction box.
If115VAC is not present, check icemaker wiring connections. If 115VAC is present,
check for voltage at condenser unit. If115VAC is not present, check eld 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.
If115VAC is not present, replace HGV (bypassing).
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d) PM Diagnosis: Conrm water is owing 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. Specication and Performance Data
Sheets." Next, check HM operation. If refrigeration pressures are above HM setpoint
and HMis 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
15pound swing is not present, replace TXV.
g) WRV Diagnosis: WRV is factory set and generally no adjustment is required.
IfWRV fails to open in freeze, check for proper refrigerant pressures. See "VIII.A.
Specication 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. Specication and Performance Data Sheets."
i) Short Freeze Cycle Diagnosis: Conrm water tank lls and overows during 1 min.
ll and harvest cycles. If not, check water supply lters, shut-off valve, WV screen.
Ifwater tank empties before 5 min. timer terminates and freeze cycle is short, check
that DV is not leaking by or energized (water owing 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
rst pump-out is dependent on CB. The rst 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
No. 5 No. 6
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
Pump-Out
Frequency
"G" Control Board
Comp and FMR continue, HGV energizes, LLV and FM de-energize. If S4dip switch 3
&4 are set to 3 off and 4on, LED 4 turns on and WV energizes. PM stops for 2sec.,
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),
after5min. of freeze disconnect CB black K5 connector (FS connector) . Check that
PM stops and re-starts and that DV energizes and water is owing 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. IfLEDs1,3, 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 X10relay.
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
X10relay. If 115VAC is present at X10 relay #3 (GY), check DV solenoid, replace as
needed. Next, conrm that the drain line is not clogged.
Conrm 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 satised or power is turned off. The
appliance always restarts at the 1-min. ll 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–oat 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, conrm 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). If115VAC is present
at HPS (P) and not at HPS (BK), HPS is open. See HPS Diagnosis below. If115VAC
is present at HPS (BK), check for 10.5VAC at CB K2#1 (R) to CB K2#2(R).
If10.5VAC 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 tting. On water-cooled models, conrm WRV opens in freeze
cycle.
Conrm 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"(30cm) 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,
FMRenergize), Continue to step 5a. If FS is open, WV remains energized through
additional 1-min. ll 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 lters 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.
Ifopen, replace WV. If the water tank lls, 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. CBmonitors 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 50sec., whichever is shorter.
50sec. before harvest terminates, PM energizes. See step 5b below.
a) Comp Diagnosis: Check that evaporator is warming. Ifnot, conrm 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).
If115VAC is present at #7 or #10 (BR or BK) and not at #1 or #9 (V), replace CB.
If115VAC is present, check for 115VAC at CR solenoid. If 115VAC is present, conrm
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).
If115VAC 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: Conrm that LLV is de-energized and closed (not bypassing).
Ifenergized, replace CB. If de-energized and bypassing, replace LLV.
d) WRV Diagnosis: Conrm WRV is not leaking by.
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