Hoshizaki KMD860MRJ User Manual
Service Manual
Modular Crescent Cuber
Model
KMD-860MAJ, MWJ, MRJ
hoshizakiamerica.com
Number: 73221
Issued: 1-30-2018
WARNING
Only qualied service technicians should install and service the appliance. To
obtain the name and phone number of your local Hoshizaki Certied Service
Representative, visit www.hoshizaki.com. No service should be undertaken until
the technician has thoroughly read this Service Manual. Failure to service and
maintain the appliance in accordance with this manual will adversely affect safety,
performance, component life, and warranty coverage and may result in costly water
damage. Proper installation is the responsibility of the installer. Product failure or
property damage due to improper installation is not covered under warranty.
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 (MAJ) ...................................................................................................... 7
2. Water-Cooled (MWJ) ............................................................................................... 8
3. Remote Air-Cooled (MRJ) ........................................................................................ 9
B. Water/Refrigeration Circuit Diagram ............................................................................ 10
1. Air-Cooled Models (MAJ) ....................................................................................... 10
2. Water-Cooled Models (MWJ) ..................................................................................11
3. Remote Models (MRJ) ........................................................................................... 12
II. Sequence of Operation and Service Diagnosis ............................................................... 13
A. Sequence of Operation Flow Chart ............................................................................. 13
1. Operation Flow Chart ............................................................................................ 13
2. Shutdown Flow Chart ............................................................................................ 14
3. Freeze-Time Correction Chart ............................................................................... 15
B. Service Diagnosis ....................................................................................................... 16
C. Freeze-Time Correction Cycle (90 min.) ..................................................................... 24
D. Control Board Check ................................................................................................... 26
E. Bin Control Check ....................................................................................................... 27
F. Float Switch Check and Cleaning ................................................................................ 29
1. Float Switch Check ................................................................................................ 29
2. Float Switch Cleaning ............................................................................................ 30
G. Thermistor Check ........................................................................................................ 31
H. Control Switch ............................................................................................................. 31
I. Diagnostic Tables .......................................................................................................... 32
J. Freeze-Up Check List .................................................................................................. 36
III. Controls and Adjustments ............................................................................................... 37
A. Control Board Layout ................................................................................................. 38
B. LED Lights and Audible Alarm Safeties ....................................................................... 39
C. Settings and Adjustments ............................................................................................ 40
1. Default Dip Switch Settings .................................................................................... 40
2. Harvest Time (S4 dip switch 1 & 2)........................................................................ 41
3. Pump-Out Time/Harvest Time During Pump-Out (S4 dip switch 3 & 4) ................. 41
4. Pump-Out Frequency Control (S4 dip switch 5) ..................................................... 42
5. Harvest Pump Time (Harvest Assist) (S4 dip switch 6) ......................................... 42
6. Harvest Pump Time (Harvest Assist)/Freeze-Time Correction (S4 dip switch 7) .. 43
7. Factory Use (S4 dip switch 8)................................................................................. 43
8. Freeze Timer (S4 dip switch 9 & 10) ...................................................................... 44
9. Float Switch Selector (S5 dip switch 1) ................................................................. 44
10. Rell Counter (S5 dip switch 2 and 3) ................................................................... 44
11. Minimum Harvest Time (S5 dip switch 4) ............................................................... 45
12. Anti-Slush (S5 dip switch 5) ................................................................................... 45
3
IV. Refrigeration Circuit and Component Service Information.............................................. 46
A. Refrigeration Circuit Service Information .................................................................... 46
B. Component Service Information .................................................................................. 49
C. Water Regulating Valve Adjustment (water-cooled model) .......................................... 49
V. Maintenance .................................................................................................................... 50
VI. Preparing the Icemaker for Periods of Non-Use ............................................................. 51
VII. Disposal ......................................................................................................................... 53
VIII. Technical Information .................................................................................................... 54
A. Specication and Performance Data Sheets ............................................................... 54
1. KMD-860MAJ ......................................................................................................... 54
2. KMD-860MWJ ....................................................................................................... 55
3. KMD-860MRJ ........................................................................................................ 56
B. Wiring Diagram ........................................................................................................... 57
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 (MAJ)
Spray Tubes
Inlet Water Valve
Thermostatic
Expansion
Valves
Water Supply Inlet
Hot Gas Valve
Junction Box
Condenser
Control Box
Float Switch
Drain Valve
Cleaning Valve
Condenser
Fan Motor
Main Transformer
Drier
Control Switch
Water Pump
Compressor
Bin Control
7
2. Water-Cooled (MWJ)
Spray Tubes
Thermostatic
Expansion
Valves
Inlet Water Valve
Water Supply Inlet
Hot Gas Valve
Junction Box
Water
Regulator
Condenser
Control Box
Float Switch
Drain Valve
Water Pump
Cleaning Valve
Control Switch
Bin Control
Main Transformer
Drier
Compressor
8
3. Remote Air-Cooled (MRJ)
Spray Tubes
Inlet Water Valve
Water Supply Inlet
Hot Gas Valve
Main Transformer
Junction
Boxes
Control Box
Receiver
Tank
Float Switch
Drain Valve
Water Pump
Cleaning Valve
Thermostatic
Expansion
Valves
Bin Control
Control Switch
Drier
Liquid Line Valve
Compressor
Crankcase Heater
9
B. Water/Refrigeration Circuit Diagram
1. Air-Cooled Models (MAJ)
10
2. Water-Cooled Models (MWJ)
11
3. Remote Models (MRJ)
12
II. Sequence of Operation and Service Diagnosis
A. Sequence of Operation Flow Chart
1. Operation Flow Chart
10th cycle
(S4 dip switch 5)
2 sec., then reverses for
10/20 sec.
• Pump motor stops for
(S4 dip switch 3 & 4)
FS in control
Comp energized
FMR energized
HGV energized
LLV de-energized
PM de-energizes for 2 sec.,
then reverses for 10/20 sec.
FS opens or freeze
timer terminates
Anti-Slush
Thermistor temperature
reaches 36°F (2.2°C)
(5.8 kΩ).
PM de-energized for
10 sec.
• Factory set for every
4. Pump-Out Cycle
CB: 2A7664-02
When freeze time differential exceeded,
freeze-time correction cycle starts.
See "II.A.3. Freeze-Time Correction Chart."
FS closed
50 sec.
Comp energized
FM energized
FMR energized
LLV energized
PM energized
HGV de-energized
FS check
FS open
3. Freeze Cycle
• Min. freeze time: 5 min.
• Max. freeze time: freeze timer setting
(S4 dip switch 9 & 10).
5-min.
minimum
freeze timer in
Harvest Pump
control
Time
Operation Flow Chart
PM energized
1 to 3-min. harvest timer in
control (S4 dip switch 1 & 2)
Thermistor
in control
HPT setting (S4 dip switch 6), whichever is shorter.
• WV time: 6 min. or the length of harvest minus
• Max. harvest time: 20 min.
2. Harvest Cycle
WV de-energized
FS closed
Thermistor temperature reaches
Comp energized
FMR energized
48°F (9°C) (3.9 kΩ or less).
Harvest timer starts.
HGV energized
WV energized
Components Energized when the Control Switch is in the "WASH" Position
The "WASH" position on the control switch is used when cleaning and sanitizing the unit. When in the "WASH" position, power is supplied
to the pump motor. With the cleaning valve closed, the cleaner and sanitizer ow over the outside of the evaporator plate assembly. With the
cleaning valve open, the cleaner and sanitizer ow over both the outside and the inside of the evaporator plate assembly.
Note: Close the cleaning valve after cleaning and sanitizing are complete, otherwise the unit will not restart when the control
switch is placed in the "ICE" position.
WV energized
13
FS open
If FS is open, Comp stops and cycle
returns to 1-Min. ll.
Legend:
BC–bin control
CB–control board
Comp–compressor
FM–fan motor
FMR–fan motor-remote
FS–oat switch
HGV–hot gas valve
HPT–harvest pump time
LLV –liquid line valve
PM–pump motor
WV–inlet water valve
Fill Cycle
1. 1-Minute
Cycle
Steps
FS check
Startup
2. Shutdown Flow Chart
2. Icemaker Off
3. Ice Level Lowered
Icemaker starts at
All components
"1. 1-Minute Fill Cycle."
de-energized.
To 1. 1-Minute Fill Cycle
BC closed
(BC actuator paddle disengaged)
Green "BC CLOSED" LED on
Yellow "BC OPEN" LED off
Yellow "BC OPEN" LED continues. All
components de-energized.
Shutdown Flow Chart
Control board 2A7664-02 retains freeze-time correction
count data between bin control restarts.
to 15 sec. into the freeze cycle if
activated at the end of the harvest cycle.
15 sec. before the 5-min. short cycle
protection timer terminates.
Otherwise, at the end of the next harvest
cycle.
BC open (BC actuator paddle engaged)
Green "BC CLOSED" LED off
Yellow "BC OPEN" LED on
BC Operation
Legend:
BC–bin control
1. Bin Full
Shutdown
Shutdown Delay:
and Restart
• Fill Cycle–15 sec. after activation.
• Harvest Cycle–At the end of the harvest cycle, or up
• Freeze Cycle– 15 sec. after activation if activated at least
14
3. Freeze-Time Correction Chart
2. 10-Minute Fill/Overow
WV energized
Comp de-energized
FMR de-energized
HGV de-energized
PM de-energized
After 5th 10-Minute Harvest Pump Cycle with WV
Freeze-Time Correction Cycle Complete.
Go to Step "3. Freeze Cycle" in Operation Flow Chart.
step 1 for 5th and nal time.
• Do not adjust S4 dip switch 7 out of the factory position.
• After step 2 completes 4th sequence (80 min. completed), repeat
1. 10-Minute Harvest Cycle with WV
Comp energized
FMR energized
HGV energized
PM energized
WV energized
2A7664-02 Freeze-Time Correction Flow Chart
Cycle Steps
Steps 1 and 2 repeat
4 times (total 80 min.),
then step 1 repeats for
a 5th time to complete
Freeze-Time Correction
Start
Legend:
Comp–compressor
FM–fan motor
FMR–fan motor-remote
HGV–hot gas valve
PM–pump motor
WV–inlet water valve
Appliance Cycle Reset and Alarm Reset:
Cycle Reset: Power Supply or Control Switch Turned Off and On again:
Appliance turns off, then re-starts at 1.Fill Cycle.
Alarm Reset: CB "ALARM RESET" pressed during or after a freeze-time
correction cycle with power supply on:
Appliance continues cycle with no interruption or reset.
CB red "POWER OK" LED blinking:
CB red "POWER OK" LED resets to solid.
CB yellow "EXT HARVEST" LED blinking:
Cycle.
Differential
Value in Sec.
3 254
4 309
5 349
6 380
7 406
8 427
9 446
10 462
CB yellow "EXT HARVEST: LED turns off.
Number of
Freeze Time Differential Exceeded.
Minimum and Maximum Freeze times have
exceeded differential parameters.
Freeze-Time Correction function is enabled
when S4 Dip Switch 7 is in the "ON" position.
CB monitors freeze time. After 3freeze cycles,
CB compares the minimum and maximum
differential of the 3 freeze cycle times. Every
freeze cycle time after the third freeze cycle
time is added to the minimum/maximum
calculation.
Example: After 8 cycles, if the differential
between the shortest cycle (minimum) and the
longest cycle (maximum) is equal to or greater
than 427 sec. a freeze-time correction cycle is
initiated:
Freeze Cycles
Note: When 1st freeze-time correction cycle
is initiated, CB "POWER OK" LED starts
blinking. On 2nd freeze-time correction cycle,
if CB "POWER OK" LED has been reset,
CB "POWER OK" LED starts blinking. If CB
"POWER OK" had not been reset after 1st
freeze-time correction cycle CB "POWER OK"
LED continues to blink.
After 3rd freeze-time correction cycle in
36hours, CB yellow "EXT HARVEST" LED
starts blinking.
Appliance continues to operate and LEDs
continue to blink until ALARM RESET button is
pressed with power on.
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.D. 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.
• The neutral (W) is provided through MT. To conrm a good neutral, check for
60VAC from white (W) neutral to ground (GND). If 60VAC is present, neutral is
good. If 60VAC is not present, check 208-230VAC main power supply to MT.
If208-230VAC is present, check MT continuity.
• When checking voltage from the CB K1 connector (10 pin connector), pull CB
K1connector 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 BC is closed and the 115VAC 10A fuse is good.
16
1. 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), check BC. Move ice away from
BC actuator paddle. If yellow "BC OPEN" LED stays on, see "II.E. Bin Control Check.".
Note: • CB red "POWER OK" LED remains on unless the 10.5VAC power supply is
interrupted (K2 connector).
• Check CB using the steps in "II.D.Control Board Check."
• Conrm CB green "BC CLOSED" LED is on. If CB yellow "BC OPEN" LED is on,
remove ice from BC. If no ice is around BC and yellow "BC OPEN" LED is on,
see "II.E. Bin Control Check."
a) Power On Diagnosis: If CB red "POWER OK" LED is off, conrm 10A fuse is good.
Check for 115VAC at control switch #1 (BR) to neutral (W) then at control switch
#2(P) to neutral (W). If 115VAC is present on #1 (BR) and not on #2(P), replace
control switch. If 115VAC is present on control switch #2 (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 red wire to CB K2 #2 red wire.
If10.5VAC is not present, check that the cleaning valve interlock switch is closed.
Next, check CT continuity. If open, replace CT.
b) HPS Diagnosis: Conrm condenser coil is not clogged or restricted. Let refrigeration
circuit pressures equalize. If HPS does not reset and pressures are equalized,
replace HPS. Ifpressures 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, HM, LLV, WRV, strainer, check valve, drier, damaged
line set or tting, and fan blade for binding.
Conrm that the location meets installation requirements. See the appliance's
instruction manual for details.
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. If harvest cycle begins (Comp,
HGV, FMR energized), continue to step 5a. If FS is open, WV remains energized until
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.F. Float Switch Check and
Cleaning." If FS is closed and CB fails to start the harvest cycle after 1 min., replace
CB.
17
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 and S5dip switch 4). WV and X11 relay are energized
during harvest for a maximum of 6 min. or the length of harvest minus HPT setting
(S4dip switch 6), whichever is shorter. 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 (V) or #9 (V) to neutral (W).
If115VAC is not present, check for 115VAC at CB K1 #7 (BR) or #10 (BR) to neutral
(W). If115VAC is present at #7 (BR) or #10 (BR) and not at #1 (V) or #9 (V), replace
CB. If 115VAC 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 and LED 2 is on, 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. If WRV is leaking by, conrm HGV
is open and LLV is closed. Next, check for proper refrigerant pressures. If refrigerant
pressures are correct, adjust or replace WRV. See "IV.C. Water Regulating Valve
Adjustment (water-cooled model)."
18
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