Hoshizaki American, Inc. KMD-450MAH, KMD-450MWH Service Manual
Hoshizaki America, Inc.
Hoshizaki
Modular Crescent Cuber
Models
KMD-450MAH
“A Superior Degree
of Reliability”
www.hoshizaki.com
KMD-450MWH
SERVICE MANUAL
™
Number: 73161
Issued: 9-3-2009
IMPORTANT
Only qualied service technicians should install, service, and maintain the
icemaker. No service or maintenance should be undertaken until the technician
has thoroughly read this Service Manual. Failure to service and maintain
the equipment in accordance with this manual may adversely affect safety,
performance, component life, and warranty coverage.
Hoshizaki provides this manual primarily to assist qualied service technicians in the
service and maintenance of the icemaker.
Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, write, or send an e-mail message to the Hoshizaki Technical
Support Department for assistance.
HOSHIZAKI AMERICA, INC.
618 Highway 74 South
Peachtree City, GA 3069
Attn: Hoshizaki Technical Support Department
Phone: 1-800-33-1940 Technical Support
(770) 487-331
Fax: 1-800-843-1056
(770) 487-3360
E-mail: techsupport@hoshizaki.com
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.
IMPORTANT
This manual should be read carefully before the icemaker is serviced or
maintenance operations are performed. Only qualied service technicians
should install, service, and maintain the icemaker. Read the warnings
contained in this booklet carefully as they give important information regarding
safety. Please retain this booklet for any further reference that may be
necessary.
CONTENTS
Important Safety Information ................................................................................................. 6
I. Specications ..................................................................................................................... 7
A. Icemaker ....................................................................................................................... 7
1. KMD-450MAH (air-cooled) ...................................................................................... 7
. KMD-450MWH (water-cooled) ................................................................................ 8
II. General Information ........................................................................................................... 9
A. Construction .................................................................................................................. 9
1. KMD-450MAH (air-cooled) ...................................................................................... 9
. KMD-450MWH (water-cooled) .............................................................................. 10
B. Sequence of Operation ............................................................................................... 11
1. Sequence Cycles and Shutdown .......................................................................... 11
a) 1-Minute Fill Cycle ........................................................................................... 11
b) Initial Harvest Cycle ........................................................................................ 11
c) Freeze Cycle ................................................................................................... 11
d) Pump-Out Cycle ............................................................................................. 1
e) Normal Harvest Cycle ...................................................................................... 1
f) Shutdown .......................................................................................................... 1
. Sequence Flow Chart ............................................................................................ 14
C. Control Board ............................................................................................................. 15
1. Control Board Layout ............................................................................................ 16
. Features ................................................................................................................ 17
a) Maximum Water Supply Period - 6 minutes .................................................... 17
b) Harvest Backup Timer and Freeze Timer ........................................................ 17
c) High Temperature Safety ................................................................................. 17
d) Low Water Safety ............................................................................................ 17
e) High Voltage and Low Voltage Cut-outs .......................................................... 17
f) LED Lights and Audible Alarm Safeties ............................................................ 18
3. Controls and Adjustments ..................................................................................... 19
a) Default Dip Switch Settings ............................................................................. 19
b) Harvest Timer (S1 dip switch 1 & ) ................................................................ 0
c) Pump-Out Timer (S1 dip switch 3 & 4) ............................................................ 0
d) Pump-Out Frequency Control (S1 dip switch 5 & 6) ........................................ 1
e) Harvest Pump Timer (S1 dip switch 7 & 8) ...................................................... 1
f) Freeze Timer (S1 dip switch 9 & 10) ................................................................
g) Pump-Out/Drain Selector (S dip switch 1) .....................................................
h) Float Switch Selector (S dip switch ) ........................................................... 3
i) Rell Counter (S dip switch 3 & 4) .................................................................. 3
j) Factory Use (S dip switch 5) ........................................................................... 3
k) Anti-Slush Control (S dip switch 6) ................................................................ 3
3
D. Bin Control .................................................................................................................. 4
E. Float Switch ................................................................................................................ 4
F. Thermistor ................................................................................................................... 4
G. Switches ..................................................................................................................... 5
1. Control Switch ....................................................................................................... 5
. Service Switch ....................................................................................................... 5
a) DRAIN .............................................................................................................. 5
b) CIRCULATE .................................................................................................... 5
c) WASH .............................................................................................................. 5
III. Technical Information ..................................................................................................... 6
A. Water Circuit and Refrigeration Circuit ....................................................................... 6
1. KMD-450MAH (air-cooled) .................................................................................... 6
. KMD-450MWH (water-cooled) .............................................................................. 7
B.
Wiring Diagram and Multimeter Access Points ...............................................................8
1. Wiring Diagram ...................................................................................................... 8
. Multimeter Access Points ...................................................................................... 9
a) Diagnostic Connector ...................................................................................... 9
b) Compressor Terminal Block ............................................................................ 9
C. Performance Data ...................................................................................................... 30
1. KMD-450MAH (air-cooled) .................................................................................... 30
. KMD-450MWH (water-cooled) .............................................................................. 31
IV. Service Diagnosis .......................................................................................................... 3
A. Diagnostic Procedure ................................................................................................ 3
B. Control Board Check .................................................................................................. 36
C. Bin Control Check and Cleaning ................................................................................ 37
1. Bin Control Check ................................................................................................. 37
. Bin Control Cleaning ............................................................................................. 37
D. Float Switch Check and Cleaning ............................................................................... 38
1. Float Switch Check ................................................................................................ 38
. Float Switch Cleaning ............................................................................................ 39
E. Thermistor Check ....................................................................................................... 41
F. Diagnostic Charts ........................................................................................................ 4
1. No Ice Production .................................................................................................. 4
. Evaporator is Frozen Up ....................................................................................... 45
3. Low Ice Production ................................................................................................ 47
4. Abnormal Ice ......................................................................................................... 48
5. Other ..................................................................................................................... 49
V. Removal and Replacement of Components ................................................................... 50
A. Service for Refrigerant Lines ...................................................................................... 50
1. Refrigerant Recovery ............................................................................................ 50
. Brazing .................................................................................................................. 51
3. Evacuation and Recharge (R-404A) ..................................................................... 51
B. Removal and Replacement of Compressor ................................................................ 5
C. Removal and Replacement of Expansion Valve......................................................... 53
D. Removal and Replacement of Hot Gas Valve or Liquid Line Valve ........................... 54
E. Removal and Replacement of Evaporator .................................................................. 55
F. Removal and Replacement of Air-Cooled Condenser ................................................ 56
G. Removal and Replacement of Water-Cooled Condenser .......................................... 56
4
H. Removal and Replacement of Water Regulating Valve (water-cooled model) ........... 58
I. Adjustment of Water Regulating Valve (water-cooled model) ...................................... 59
J. Removal and Replacement of Thermistor ................................................................... 60
K. Removal and Replacement of Fan Motor (air-cooled and remote air-cooled models) 61
L. Removal and Replacement of Water Valves............................................................... 61
M. Removal and Replacement of Pump Motor ............................................................... 6
N. Removal and Replacement of Control Board ............................................................. 6
VI. Cleaning and Maintenance ............................................................................................ 63
A. Cleaning and Sanitizing Instructions ........................................................................... 63
1. Cleaning Procedure ............................................................................................... 63
. Sanitizing Procedure - Following Cleaning Procedure .......................................... 65
B. Maintenance ............................................................................................................... 66
C. Preparing the Icemaker for Long Storage .................................................................. 67
5
Important Safety Information
Throughout this manual, notices appear to bring your attention to situations which could
result in death, serious injury, or damage to the unit.
WARNING Indicates a hazardous situation which could result in death or
serious injury.
CAUTION Indicates a situation which could result in damage to the unit.
IMPORTANT Indicates important information about the use and care of the
unit.
WARNING
This icemaker 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
eventual damage caused by improper, incorrect, and unreasonable use.
To reduce the risk of death, electric shock, serious injury, or re, follow
basic precautions including the following:
• 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 severe damage to
equipment.
• This unit requires an independent power supply. See the nameplate for
proper voltage and breaker/fuse size. Failure to use a proper breaker or fuse
can result in a tripped breaker, blown fuse, or damage to existing wiring. This
could lead to heat generation or re.
• THIS UNIT MUST BE GROUNDED. Failure to properly ground this unit could
result in death or serious injury.
• This unit should be disassembled or repaired only by qualied service
personnel to reduce the risk of electric shock, injury, or re.
• Do not make any alterations to the unit. Alterations could result in electric
shock, injury, re, or damage to the unit.
6
I. Specications
AC SUPPLY VOLTAGE 115-120/60/1 (3 wire with netrual for 115V)
AMPERAGE 10.0 A ( 5 Min. Freeze AT 104°F / WT 80°F)
MINIMUM CIRCUIT AMPACITY 15 A
MAXIMUM FUSE SIZE 15 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp.(°F) 50 70 90
lbs./day ( kg/day ) 70 *457 (207) 436 (198) 398 (180)
Reference without *marks 80 441 (200) 409 (186) 365 (165)
90 436 (198) *387 (176) 344 (156)
100 425 (193) 377 (171) 304 (138)
SHAPE OF ICE Crescent Cube
ICE PRODUCTION PER CYCLE 9.6 lbs. (4.3 kg) 432pcs.
APPROXIMATE STORAGE CAPACITY N/A
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 880(5.48) 810(4.28)
WATER gal./24HR (gal./100 lbs.) 73(18.9) 192(42.1)
CEC/CEE TIER LEVEL 3
ENERGY STAR YES
EXTERIOR DIMENSIONS (WxDxH) 30" x 24-1/4" x 22-1/8" (762 x 617 x 562 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT Net 130 lbs. (59 kg), Shipping 170 lbs. (77 kg)
CONNECTIONS - ELECTRIC Permanent - Connection
- WATER SUPPLY Inlet 1/2" FPT
- DRAIN Outlet 3/4" FPT
5/8" OD Tube
CUBE CONTROL SYSTEM Float Switch
HARVESTING CONTROL SYSTEM Hot Gas and Water, Thermistor and Timer
ICE MAKING WATER CONTROL Timer Controlled. Overflow Pipe
COOLING WATER CONTROL N/A
BIN CONTROL SYSTEM Mechanical Lever Switch and Timer
COMPRESSOR Hermetic, Model RST45C1E-CAA-202
CONDENSER Air-Cooled , Fin and tube type
EVAPORATOR Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R404A, 1 lb. 5.2 oz. (600g)
DESIGN PRESSURE High 467PSIG, Low 230PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out ( Internal )
COMPRESSOR PROTECTION Auto-reset Overload Protector ( Internal )
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch
ACCESSORIES -SUPPLIED N/A
-REQUIRED Ice Dispenser or Ice Storage Bin
OPERATING CONDITIONS VOLTAGE RANGE 104 - 127 V
AMBIENT TEMP. 45 -100° F
WATER SUPPLY TEMP. 45 - 90° F
WATER SUPPLY PRESSURE 10 - 113 PSIG
A. Icemaker
1. KMD-450MAH (air-cooled)
Note: We reserve the right to make changes in specications and design without prior
notice.
7
2. KMD-450MWH (water-cooled)
AC SUPPLY VOLTAGE 115-120/60/1 (3 wire with netrual for 115V)
AMPERAGE 8.5A ( 5 Min. Freeze AT 104°F / WT 80°F)
MINIMUM CIRCUIT AMPACITY 15 A
MAXIMUM FUSE SIZE 15 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp.(°F) 50 70 90
lbs./day ( kg/day ) 70 *460 (209) 447 (203) 415 (188)
Reference without *marks 80 450 (204) 429 (195) 389 (177)
90 447 (203) *415 (188) 377 (171)
100 436 (198) 406 (184) 343 (156)
SHAPE OF ICE Crescent Cube
ICE PRODUCTION PER CYCLE 9.3 lbs. (4.2 kg) 432pcs.
APPROXIMATE STORAGE CAPACITY N/A
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 790(4.55) 790(4.14)
WATER gal./24HR (gal./100 lbs.) 74(17.8) 145(31.6)
WATER COOLED CONDENSER 523(126) 315(68)
gal./24HR (gal./100 lbs.)
CEC/CEE TIER LEVEL 3
ENERGY STAR N/A
EXTERIOR DIMENSIONS (WxDxH) 30" x 24-1/4" x 22-1/8" (762 x 617 x 562 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT Net 130 lbs. (59 kg), Shipping 170 lbs. (77 kg)
CONNECTIONS - ELECTRIC Permanent - Connection
- WATER SUPPLY Inlet 1/2" FPT Cond. Inlet 1/2" FPT
- DRAIN Outlet 3/4" FPT Cond. Outlet 3/8" FPT
5/8" OD Tube
CUBE CONTROL SYSTEM Float Switch
HARVESTING CONTROL SYSTEM Hot Gas and Water, Thermistor and Timer
ICE MAKING WATER CONTROL Timer Controlled. Overflow Pipe
COOLING WATER CONTROL Pressure Regulator
BIN CONTROL SYSTEM Mechanical Lever Switch and Timer
COMPRESSOR Hermetic, Model RST45C1E-CAA-202
CONDENSER Water-cooled, Tube in tube type
EVAPORATOR Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R404A, 1 lb. 0.9 oz. (480g)
DESIGN PRESSURE High 427PSIG, Low 230PSIG
P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out ( Internal )
COMPRESSOR PROTECTION Auto-reset Overload Protector ( Internal )
REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch
LOW WATER PROTECTION Float Switch
ACCESSORIES -SUPPLIED N/A
-REQUIRED Ice Dispenser or Ice Storage Bin
OPERATING CONDITIONS VOLTAGE RANGE 104 - 127 V
AMBIENT TEMP. 45 -100° F
WATER SUPPLY TEMP. 45 - 90° F
WATER SUPPLY PRESSURE 10 - 113 PSIG
Note: We reserve the right to make changes in specications and design without prior
notice.
8
II. General Information
A. Construction
1. KMD-450MAH (air-cooled)
Spray Tube
Inlet Water
Valve
Water Tank
Water Guide
Spray Guide
Wash Valve
Water Supply Inlet
Expansion Valve
Junction Box
Hot Gas Valve
Condenser
Condenser Fan
Motor
Control Switch
Service Switch
Drain Valve
Drier
Compressor
Pump Motor
Control Box
Float Switch
Bin Control
9
2. KMD-450MWH (water-cooled)
Water Guide
Spray Guide
Spray Tube
Wash Valve
Water Supply Inlet
Expansion Valve
Junction Box
Hot Gas Valve
Condenser
Inlet Water
Valve
Drain Valve
Water Tank
Pump Motor
Water Regulator
Control Switch
Service Switch
Compressor
Drier
Control Box
Float Switch
Bin Control
10
B. Sequence of Operation
1. Sequence Cycles and Shutdown
The steps in the sequence are as outlined below. When power is supplied, CB "POWER
OK" LED comes on. There is a 5-second delay before startup. Note that the order of the
component LEDs from the outer edge of CB is 5, 6, 8, 9, 4, 7.
a) 1-Minute Fill Cycle
LED 8 is on. WV energizes and the 1-minute ll cycle begins. After 1 minute, CB checks
for a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV remains energized
through additional 1-minute ll cycles until water lls the tank and closes F/S. This
serves as a low water safety to protect PM.
b) Initial Harvest Cycle
LEDs 5, 6, and 8 are on. WV remains energized, Comp, FMR, 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 a 3.9 kΩ signal from the thermistor
and turns harvest termination over to the harvest timer (S1 dip switch 1 & ). The
harvest timer has settings of 60, 90, 10, and 180 seconds. For details, see "II.C.3.b)
Harvest Timer (S1 dip switch 1 & )." WV is energized during harvest for a maximum of
6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (harvest pump timer
(S1 dip switch 7 & 8)), whichever is shorter. For details, see "II.C.3.e) Harvest Pump
Timer (S1 dip switch 7 & 8)." LED 8 goes off when WV de-energizes. LED 7 comes on
and PM energizes and runs for the last 0, 10, 30, or 50 seconds of harvest depending
on the harvest pump timer setting. This circulates water over the evaporator for the last
0, 10, 30, or 50 seconds of harvest. When the harvest timer expires, the harvest cycle is
complete. CB checks the position of F/S and proceeds to the freeze cycle if it is closed
or calls for a 1-minute ll cycle if it is open. The minimum total time allowed by CB for a
complete harvest cycle is minutes.
c) Freeze Cycle
LEDs 5 & 7 are on. Comp and FMR remain energized, PM energizes or remains
energized depending on the harvest pump timer (S1 dip switch 7 & 8) setting. FM and
LLV energize, HGV and WV (may de-energize during harvest cycle) de-energize. CB
monitors the cooling of the evaporator via the thermistor located on the suction line.
When the thermistor drops to 36°F (°C), CB reads a 5.5 kΩ signal from the thermistor
and starts a 5-minute short cycle protection timer. CB will not accept a signal from F/S
until the 5-minute timer expires. After the 5-minute timer expires, F/S assumes control.
As ice builds on the evaporator, the water level in the tank lowers. The freeze cycle
continues until F/S opens and terminates the cycle.
The oat switch selector (S dip switch ) and the rell counter (S dip switch 3 & 4)
allow certain models to use a double F/S to rell the water tank during the freeze cycle.
The KMD-450MAH and KMD-450MWH use a single F/S and do not rell. For details,
see "II.C.3.h) Float Switch Selector (S dip switch )" and "II.C.3.i) Rell Counter (S dip
switch 3 & 4)." CAUTION! Do not adjust S2 dip switch 2, 3, or 4 out of the factory
default position on this model. These dip switches must be left in the factory
default position or this unit will not operate correctly.
The anti-slush control (S dip switch 6) helps prevent slushing during the freeze cycle
on certain models. When activated, the control board monitors the cooling of the
11
evaporator via the thermistor located on the suction line. When the thermistor drops to
34°F (1°C), the control board reads a 5.8 kΩ signal from the thermistor and de-energizes
PM for 10 seconds. The anti-slush control is deactivated on the KMD-450MAH and
KMD-450MWH. CAUTION! Do not adjust S2 dip switch 6 out of the factory default
position on this model. This dip switch must be left in the factory default position
or this unit will not operate correctly.
d) Pump-Out Cycle
LEDs 5, 6, 4, and 7 are on. Comp and FMR remain energized, HGV energizes, LLV and
FM de-energize. DV energizes after a -second delay. PM de-energizes for seconds
and then re-energizes, or de-energizes and stays off depending on the pump-out/drain
selector (S dip switch 1) setting. For details, see "II.C.3.g) Pump-Out/Drain Selector
(S dip switch 1)." When the pump-out/drain selector is set to pump-out, PM takes water
from the tank and forces it through DV and down the drain. When the pump-out/drain
selector is set to drain, water drains by gravity through DV. CAUTION! Do not adjust
S2 dip switch 1 out of the factory default position on this model. This dip switch
must be left in the factory default position or this unit will not operate correctly.
Pump-out lasts 10 or 0 seconds depending on the pump-out timer (S1 dip switch 3 & 4)
setting. When the pump-out timer expires, the pump-out is complete. For details, see "II.
C.3.c) Pump-Out Timer (S1 dip switch 3 & 4)."
The rst pump-out occurs after the 1st freeze cycle, then every 10th cycle thereafter.
The pump-out frequency is factory set, and generally no adjustment is required.
However, if the icemaker needs a pump-out more often due to local water conditions, the
pump-out frequency can be adjusted. The pump-out frequency control (S1 dip switch 5
& 6) can be set to have a pump-out occur every cycle, or every , 5, or 10 cycles. For
details, see "II.C.3.d) Pump-Out Frequency Control (S1 dip switch 5 & 6)."
e) Normal Harvest Cycle
Same as the initial harvest cycle. See "II.B.1.b) Initial Harvest Cycle."
Note: Unit continues to cycle until BC is satised or power is turned off. The unit always
restarts at the 1-minute ll cycle.
f) Shutdown
When BC is activated (BC open), the "POWER OK" LED ashes. There is a delay before
the shutdown sequence begins. The delay varies depending on the cycle the icemaker is
in at the time of activation. For details, see the table below.
Cycle at Bin Control Activation Delay Before Shutdown Sequence Begins
Fill Cycle 15 seconds
Harvest Cycle 15 seconds after the next freeze cycle starts
Freeze Cycle 15 seconds if BC is activated between the beginning of freeze and
termination of the 5-minute short cycle protection timer (timer starts
when the thermistor temperature drops to 36°F (°C) (5.5 kΩ or
more)). After this time, the unit will not shut down until the next harvest
cycle is complete.
After the delay, all components de-energize. DV energizes after seconds.
PM energizes after seconds or stays off depending on the pump-out/drain selector
(S dip switch 1) setting. For details, see "II.C.3.g) Pump-Out/Drain Selector (S dip
1
switch 1)." When the pump-out/drain selector is set to pump-out, PM takes water from
the tank and forces it through DV and down the drain. When the pump-out/drain selector
is set to drain, water drains by gravity through DV. CAUTION! Do not adjust S2 dip
switch 1 out of the factory default position on this model. This dip switch must be
left in the factory default position or this unit will not operate correctly. The water
tank drains for a maximum of 5 minutes or until F/S opens. DV and PM (if applicable)
then de-energize. When BC closes again calling for ice, the unit starts at the 1-minute ll
cycle. There is a 90-second minimum off time before the icemaker can restart.
Legend: BC–bin control; CB–control board; Comp–compressor; DV–drain valve; FM –fan
motor; FMR–fan motor-remote; F/S–oat switch; HGV–hot gas valve; LLV–liquid
line valve; PM–pump motor; WV–inlet water valve
13
2. Sequence Flow Chart
seconds (S dip
switch 1), then
10th cycle (S1 dip
switch 5 & 6)
• Factory set for every
4. Pump-Out Cycle
(S1 dip switch 9 & 10)
• Minimum freeze time: 5 minutes
• Maximum freeze time: freeze timer setting
3. Freeze Cycle
runs for 10/0 sec.
• PM stops for
(S1 dip switch 3 & 4)
F/S in
control
5-minute
timer in
control
Thermistor
in control
Comp continues
F/S open or
freeze timer
expires
F/S closed
Comp continues
FMR continues
HGV energized
DV & PM de-energized for sec.,
then energized for
10/0 sec.
FM de-energized
LLV de-energized
Thermistor temperature
drops to 36°F (°C)
(5.5 kΩ or more).
5-minute short cycle
protection timer starts.
FMR continues
PM continues
FM energized
LLV energized
HGV de-energized
To 1 above
No ice pressing
against BC
actuator.
Icemaker starts at
"1. 1-Minute Fill
4. Ice Level Lowered
Minimum off time:
90 seconds
3. Icemaker Off
Until F/S Opens
Maximum drain
2. Water Tank Drains
Cycle."
time: 5 minutes
BC closed
"POWER OK" LED on
(not ashing)
F/S open
DV de-energized
PM de-energized
All components
de-energized.
DV energized after sec.
PM energized after sec.
F/S check
PM energized
0, 10, 30, or 50 sec.
(S1 dip switch 7 & 8)
Harvest Pump Timer
1 to 3-min. timer in control
KMD-450MAH, KMD-450MWH
(S1 dip switch 1 & )
WV de-energized
Thermistor temperature
reaches 48°F (9°C)
F/S open
(3.9 kΩ or less).
Harvest timer starts.
"H" Control Board Sequence Flow Chart
Thermistor in
• Maximum harvest time: 0 min.
control
F/S closed
F/S check
WV continues
Comp energized
FMR energized
HGV energized
F/S open
WV energized
If F/S is open, compressor stops and cycle returns to 1-Minute Fill Cycle
10, 30, or 50 sec. (S1 dip switch 7 & 8), whichever
is shorter.
• WV time: 6 min. or the length of harvest minus 0,
2. Harvest Cycle
Cycle
1. 1-Minute Fill
termination of 5-minute short cycle protection timer (timer starts when thermistor
temperature drops to 36°F (°C) (5.5 kΩ or more)). After this time, unit will not
Delay After Bin Control is Activated:
• Fill Cycle–15 seconds.
• Harvest Cycle–15 seconds after freeze cycle starts.
1. Bin Full
shut down until next harvest cycle is complete.
• Freeze Cycle–15 seconds if BC is activated between beginning of freeze and
BC open
"POWER OK" LED ashing
the evaporator for extended periods of time.
the inside and outside surfaces of the evaporator.
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
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 icemaker is in service mode. The
service switch has three positions: "DRAIN," "CIRCULATE," and "WASH." See the information below for details of each function.
WASH Power is supplied to the pump motor and wash valve. This is used to circulate cleaner and sanitizer over both
Cycle Steps
Initial startup
begins here
after 5-sec.
delay
Bin Control
14
Shutdown
and Restart
BC Operation
Legend:
BC–bin control
Comp–compressor
DV–drain valve
FM–fan motor
FMR–fan motor-remote
F/S–oat switch
HGV–hot gas valve
LLV–liquid line valve
PM–pump motor
WV–inlet water valve
C. Control Board
• A Hoshizaki exclusive solid-state control board is employed in KMD-450MAH and
KMD-450MWH Modular Crescent Cubers.
• All models are pretested and factory set.
• For a control board check procedure, see "IV.B. Control Board Check."
CAUTION
1. The control board is fragile; handle very carefully.
. The control board contains integrated circuits, which are susceptible to
failure due to static discharge. It is especially important to touch the metal
part of the unit before handling or replacing the control board.
3. Do not touch the electronic devices on the control board or the back of the
control board.
4. Do not change wiring and connections.
5. Always replace the whole control board assembly if it goes bad.
6. Do not short out power supply to test for voltage.
15
1. Control Board Layout
• Relay LEDs (6)
(indicate which
relays are energized
as listed below)
• LED 5 (X1 Relay)
Compressor (Comp)
Fan Motor-Remote
(FMR)
• LED 6 (X2 Relay)
Hot Gas Valve (HGV)
Fan Motor (FM)
Liquid Line Valve (LLV)
(FM and LLV off when
LED on)
• LED 8 (X4 Relay)
Inlet Water Valve (WV)
(WV1) on units with
inlet water valves
• LED 9 (X5 Relay)
Inlet Water Valve
(WV) on units with
inlet water valves
• LED 4 (X6 Relay)
Drain Valve (DV)
• LED 7 (X3 Relay)
Pump Motor (PM)
"H" Control Board
• K7 Connector
Transformer
• K3 Connector
Magnetic Contactor
• "POWER OK" LED
(Lights when power is
supplied to the board.
Flashes when bin
control is activated.)
• K5 Connector
Pins
#1 Fan Motor (FM)
Liquid Line Valve (LLV)
# Hot Gas Valve
#3 Pump Motor
#4 Inlet Water Valve
#5 Open
#6 Drain Valve
• K6 Connector
Open
• K1 Connector
Pins
#1, 3 Float Switch
# Open
#4, 5 Bin Control
#6, 7 Thermistor
#8, 9 Open
• S1 Dip Switch
• S2 Dip Switch
"H" Control Board
Part Number P00013-0
16
• Alarm Buzzer
• "OUTPUT TEST" Button
(used to test relays on
control board)
• "ALARM RESET" Button
2. Features
a) Maximum Water Supply Period - 6 minutes
The inlet water valve is open during harvest for 6 minutes or the length of harvest
minus 0, 10, 30, or 50 seconds (harvest pump timer (S1 dip switch 7 & 8)), whichever is
shorter. For details, see "II.C.3.e) Harvest Pump Timer (S1 dip switch 7 & 8)."
b) Harvest Backup Timer and Freeze Timer
The harvest backup timer shuts down the icemaker if, for two cycles in a row, the harvest
cycle takes more than 0 minutes to complete. The control board signals this problem
using beeps every 3 seconds.
The freeze timer shuts down the icemaker if, for two cycles in a row, the freeze cycle
takes longer than the time specied to complete. The control board signals this problem
using 3 beeps every 3 seconds. The time is factory set using S1 dip switch 9 & 10. For
details, see "II.C.3.f) Freeze Timer (S1 dip switch 9 & 10)."
The "ALARM RESET" button on the control board must be pressed with power on to
reset either of these safeties.
c) High Temperature Safety
The temperature of the suction line in the refrigeration circuit is limited by the high
temperature safety. This protects the unit from excessively high temperatures. If the
evaporator temperature reaches 17°F±7°F (53°C±4°C), the control board reads a .8 kΩ
signal from the thermistor and shuts down the icemaker.
The control board will signal this problem using 1 beep every 3 seconds. The "ALARM
RESET" button on the control board must be pressed with power on to reset the safety.
d) Low Water Safety
The control board checks the position of the oat switch at the end of the initial 1-minute
ll cycle and at the end of each harvest cycle. If the oat switch is in the up position
(electrical circuit closed), the control board changes to the next cycle. If the oat switch
is in the down position (electrical circuit open), the control board changes to additional
1-minute ll cycles until water lls the tank and closes the oat switch. When the oat
switch closes, the control board changes to the next cycle. The unit will not start without
adequate water in the tank. This serves as a low water safety to protect the water pump.
For water-cooled model, if the condenser water supply is shut off, the unit is protected by
the high-pressure switch.
e) High Voltage and Low Voltage Cut-outs
The maximum and minimum allowable supply voltages of this icemaker are limited by
the high voltage and low voltage cut-outs. If miswiring (especially on single phase 3 wire
models) causes excessive voltage (147Vac±5% or more), the high voltage cut-out shuts
down the circuit in 3 seconds and the icemaker automatically stops. The control board
will signal this problem using 7 beeps every 3 seconds.
The icemaker also automatically stops in cases of insufcient voltage (9Vac±5% or
less). The control board signals this problem using 6 beeps every 3 seconds.
When the proper supply voltage is resumed, the icemaker automatically starts running
again.
17
f) LED Lights and Audible Alarm Safeties
At startup, a 5-second delay occurs to stabilize the circuit. The "POWER OK" LED
indicates proper control voltage and remains on unless a control voltage problem
occurs. The "POWER OK" LED ashes continuously when the bin is full and PM and DV
energize for a maximum of 5 minutes to drain the water tank. LEDs 4 through 9 energize
and sequence from initial startup as listed in the table below. Note that the order of the
LEDs from the outer edge of the control board is 5, 6, 8, 9, 4, 7. For details, see "II.B.
Sequence of Operation."
Sequence Step LED
1-Minute Fill Cycle 8 WV 1 minute
Harvest Cycle 5, 6, 8 Comp, FMR, HGV, WV minutes 0 minutes 3 to 5 minutes
Harvest Pump Timer 5, 6, 7 Comp, FMR, HGV, PM 0 seconds 50 seconds harvest pump
Freeze Cycle 5, 7 Comp, FM/FMR, PM,
Pump-Out Cycle 5, 6, 4, 7* Comp, FMR, HGV, DV,
Energized
Components
LLV
PM*
Min. Max. Avg.
5 minutes freeze timer
10 seconds 0 seconds *pump-out/drain
Time LEDs are On
timer setting
30 to 35 minutes
setting
selector setting
The built-in safeties shut down the unit and have alarms as listed below.
No. of Beeps
(every 3 sec.)
1 High Evaporator Temp.
(temperature > 17°F)
(53°C)
Harvest Backup Timer
(harvest > 0 min. for two cycles
in a row)
3 Freeze Timer
(freeze > freeze timer setting for
two cycles in a row)
To reset the above safeties, press the "ALARM RESET" button with the power supply on.
6 Low Voltage
(9Vac±5% or less)
7 High Voltage
(147Vac±5% or more)
Type of Alarm Notes
Check for harvest problem (stuck HGV or relay), hot
water entering unit, stuck HM, or shorted thermistor.
Check for open thermistor, HGV not opening, TXV or
LLV leaking by, low charge, inefcient Comp, or WRV
leaking by.
Check for F/S stuck closed (up), WV leaking by, HGV
leaking by, PM not pumping, TXV not feeding properly,
LLV not opening, low charge, HM not bypassing, or
inefcient Comp.
"POWER OK" LED turns off if voltage protection
operates.
The control voltage safeties automatically reset when
voltage is corrected.
Legend: Comp–compressor; DV–drain valve; FM–fan motor; FMR–fan motor-remote;
F/S–oat switch; HGV–hot gas valve; HM–headmaster (C.P.R.);
LLV–liquid line valve; PM–pump motor; TXV–thermostatic expansion valve;
WRV–water regulating valve; WV–inlet water valve
18
3. Controls and Adjustments
CAUTION
Dip switches are factory set. Failure to maintain factory settings may adversely
affect performance and warranty coverage. For more information, contact
Hoshizaki Technical Support at 1-800-33-1940.
a) Default Dip Switch Settings
The dip switches are factory set to the following positions:
S1 Dip Switch
Dip Switch No. 1 2 3 4 5 6 7 8 9 10
KMD-450MAH OFF OFF ON ON ON ON ON ON OFF ON
KMD-450MWH OFF OFF ON ON ON ON ON ON OFF OFF
S2 Dip Switch (Do Not Adjust)
Dip Switch No.
KMD-450MAH ON OFF OFF OFF OFF ON
KMD-450MWH ON OFF OFF OFF OFF ON
1 2 3 4 5 6
S1 Dip Switch S2 Dip Switch
Freeze Timer (9 & 10)
Anti-Slush
Control (6)
Harvest Pump Timer
(7 & 8)
Pump-Out Frequency
Control (5 & 6)
Factory Use (5)
Rell Counter (3 & 4)
Float Switch
Selector ()
Pump-Out Timer (3 & 4)
Harvest Timer (1 & )
Pump-Out/Drain
Selector (1)
19
b) Harvest Timer (S1 dip switch 1 & 2)
The harvest timer starts when the thermistor reaches 48°F (9°C) at the evaporator
outlet and the control board reads the thermistor's 3.9 kΩ signal. The harvest timer is
factory set, and generally no adjustment is required. However, a setting longer than the
factory setting may be advised in cases where the ush provided at harvest needs to be
prolonged for extra cleaning. Before changing this setting, contact Hoshizaki Technical
Support at 1-800-33-1940 for recommendations. Keep in mind that setting the harvest
timer to a longer setting decreases 4-hour production.
Note that the pump-out timer (S1 dip switch 3 & 4) acts in place of the harvest timer
during cycles with a pump-out. For details, see "II.C.3.c) Pump-Out Timer (S1 dip switch
3 & 4)."
S1 Dip Switch Setting
No. 1 No. 2
OFF OFF 60
ON OFF 90
OFF ON 10
ON ON 180
Time
(seconds)
c) Pump-Out Timer (S1 dip switch 3 & 4)
When a pump-out is called for, the pump motor de-energizes after the preceding freeze
cycle. seconds later, the pump motor and drain valve energize. The pump motor
takes water from the tank and forces it through the drain valve and down the drain. The
pump motor drains the water tank for the time determined by the pump-out timer. The
pump-out timer also acts in place of the harvest timer during cycles with a pump-out.
The pump-out timer is factory set, and generally no adjustment is required. However, if
the default is 10 seconds and the icemaker needs a longer pump-out due to local water
conditions, the pump-out timer can be adjusted to 0 seconds.
S1 Dip Switch Setting Time (seconds)
No. 3 No. 4 T1 T2
OFF OFF 10 10
ON OFF 10 180
OFF ON 0 10
ON ON 0 180
T1: Time to drain the water tank
T: Harvest timer at pump-out
0
d) Pump-Out Frequency Control (S1 dip switch 5 & 6)
The pump-out frequency control is factory set to drain the water tank every 10 cycles,
and generally no adjustment is required. However, if the icemaker needs a pump-out
more often due to local water conditions, the pump-out frequency can be adjusted. The
pump-out frequency control can be set to have a pump-out occur every cycle, or every ,
5, or 10 cycles. After startup, the rst pump-out occurs after the 1st freeze cycle.
S1 Dip Switch Setting
No. 5 No. 6
OFF OFF Every cycle
ON OFF Every cycles
OFF ON Every 5 cycles
ON ON Every 10 cycles
Frequency
e) Harvest Pump Timer (S1 dip switch 7 & 8)
CAUTION
Factory set for proper operation. Do not adjust. Adjustment outside of the
factory default setting may result in damage to the icemaker.
Depending on the harvest pump timer setting, the pump motor energizes and runs for
the last 0, 10, 30, or 50 seconds of harvest. When the pump motor is on, water circulates
over the evaporator. The water valve is energized during harvest for a maximum of
6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (determined by the
harvest pump timer setting), whichever is shorter.
S1 Dip Switch Setting
No. 7 No. 8
OFF OFF 0
ON OFF 10
OFF ON 30
ON ON 50
Time
(seconds)
1
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