Hoshizaki IM-50BAA-LM User manual

Model
IM-50BAA-Q
IM-50BAA-LM
Self-Contained Cuber
Service Manual
Number: M041-1092
Issued: 05-31-2022
hoshizakiamerica.com

1
WARNING
Only qualied service technicians should install and service the icemaker. To obtain
the name and phone number of your local Hoshizaki Certied 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 a󰀨ect safety, performance, component life,
and warranty coverage and may result in costly water damage. Proper installation is
the responsibility of the installer. Product failure or property damage due to improper
installation is not covered under warranty.
Hoshizaki provides this manual primarily to assist qualied service technicians in the
maintenance and service of the product.
Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, write, or send an e-mail message to the Hoshizaki Technical
Support Department for assistance.
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
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 ................................................................................................. 4
I. Construction and Water/Refrigeration Circuit Diagram ...................................................... 6
A. Construction .................................................................................................................. 6
B. Water/Refrigeration Circuit Diagram ............................................................................. 9
II. Sequence of Operation and Service Diagnosis ............................................................... 10
A. Sequence of Operation Flow Chart ............................................................................ 10
B. Sequence of Operation ............................................................................................... 12
C. Service Diagnosis Table ............................................................................................. 16
D. Bin Control Check and Cleaning ................................................................................ 18
1. Bin Control Check ................................................................................................. 18
2. Bin Control Cleaning ............................................................................................. 20
E. Evaporator Thermistor Check ..................................................................................... 22
III. Controls and Adjustments............................................................................................... 23
A. Control Switch ............................................................................................................. 23
B. Control Board .............................................................................................................. 23
1. Control Board Layout ............................................................................................ 24
C. Control Buttons ........................................................................................................... 25
1. RESET Button ....................................................................................................... 25
2. SERVICE 1 and SERVICE 2 Buttons .................................................................... 25
D. Control Board Settings ............................................................................................... 26
E. Control Board Information Display .............................................................................. 31
F. Control Board Model Code Setting .............................................................................. 33
1. Control Board Replacement .................................................................................. 33
G. Error Codes ................................................................................................................ 33
1. Error Codes ........................................................................................................... 33
2. Service Diagnosis.................................................................................................. 36
IV. Refrigeration Circuit and Component Service Information ............................................. 36
A. Refrigeration Circuit Service Information .................................................................... 36
1. Refrigerant Recovery ............................................................................................ 36
2. Brazing .................................................................................................................. 37
3. Evacuation and Recharge (R-134a) ...................................................................... 37
B. Component Service Information ................................................................................. 37
1. Cabinet .................................................................................................................. 37
[a] Top Panel, Top Insulation, Top Cover .............................................................. 37
[b] Front Frame, Drain Pan ................................................................................... 39
[c] Front Panel (Lower) ......................................................................................... 39
[d] Rear Panel ....................................................................................................... 39
[e] Door Assembly, Slope, Spring ......................................................................... 39
2. Refrigeration Circuit............................................................................................... 40

3
[a] Compressor ..................................................................................................... 40
[b] Condenser ....................................................................................................... 40
[c] Hot Gas Valve .................................................................................................. 41
[d] Upper Evaporator (IM-50BAA-Q) ..................................................................... 42
[e] Evaporator (IM-50BAA-LM) ............................................................................ 45
[f] Fan Motor ......................................................................................................... 46
3. Icemaking Mechanism (IM-50BAA-Q) ................................................................... 47
[a] Actuator Motor Assembly ................................................................................. 47
[b] Cam Shaft Assembly ....................................................................................... 47
[c] Water Plate Switch ........................................................................................... 47
[d] Cam Switch ...................................................................................................... 47
[e] Water Tank Assembly ...................................................................................... 47
[f] Lower Evaporator ............................................................................................. 47
[g] Evaporator Base .............................................................................................. 47
[h] Pump Motor ..................................................................................................... 47
[i] Water Tank ........................................................................................................ 47
[j] Ice Guide ........................................................................................................... 51
4. Icemaking Mechanism (IM-50BAA-LM)................................................................. 53
V. Maintenance .................................................................................................................... 55
VI. Preparing the Appliance for Periods of Non-Use ........................................................... 56
VII. Disposal ........................................................................................................................ 58
VIII. Technical Information ................................................................................................... 59
A. Specication Data ....................................................................................................... 59
B. Performance Data ....................................................................................................... 61
C. Wiring Diagram ........................................................................................................... 63

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 installation, use, and
care of the appliance.
WARNING
The appliance should be destined only to the use for which it has been expressly
conceived. Any other use should be considered improper and therefore dangerous.
The manufacturer cannot be held responsible for injury or damage resulting from
improper, incorrect, and unreasonable use. Failure to service and maintain the
appliance in accordance with this manual will adversely a󰀨ect 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 qualied service technicians should install and service the appliance.
• The appliance must be installed in accordance with applicable national, state, and
local codes and regulations.
• The appliance requires an independent power supply of proper capacity. See the
nameplate for electrical specications. Failure to use an independent power supply
of proper capacity can result in a tripped breaker, blown fuse, damage to existing
wiring, or component failure. This could lead to heat generation or re.
• THE APPLIANCE MUST BE GROUNDED: The appliance is equipped with a NEMA
5-15 three-prong grounding plug to reduce the risk of potential shock hazards.
It must be plugged into a properly grounded, independent 3-prong wall outlet. If
the outlet is a 2-prong outlet, it is your personal responsibility to have a qualied
electrician replace it with a properly grounded, independent 3-prong wall outlet. Do
not remove the ground prong from the plug and do not use an adapter plug. Failure
to properly ground the appliance could result in death or serious injury.
• Do not use an extension cord.
• To reduce the risk of electric shock, do not touch the control switch or plug with
damp hands. Make sure the control switch is in the "OFF" position before plugging
in or unplugging the appliance.
• Do not use an appliance with a damaged power cord. The power cord should not
be altered, jerked, bundled, weighed down, pinched, or tangled. Such actions could
result in electric shock or re. To unplug the appliance, be sure to pull the plug, not
the cord, and do not jerk the cord.
• Do not make any alterations to the appliance. Alterations could result in electric
shock, injury, re, or damage to the appliance.

5
WARNING, continued
• The appliance is not intended for use by persons (including children) with reduced
physical, sensory, or mental capabilities, or lack of experience and knowledge,
unless they have been given supervision or instruction concerning use of the
appliance by a person responsible for their safety.
• Young children should be properly supervised around the appliance.
• Do not climb, stand, or hang on the appliance or appliance door or allow children or
animals to do so. Serious injury could occur or the appliance could be damaged.
• Be careful not to pinch ngers when opening and closing the door. Be careful when
opening and closing the door when children are in the area.
• Do not use combustible spray or place volatile or 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.
NOTICE
• Protect the oor when moving the appliance to prevent damage to the oor.
• Follow the water supply, drain connection, and maintenance instructions carefully to
reduce the risk of costly water damage.
• In areas where water damage is a concern, install in a contained area with a 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).
• If water collects in the bin and will not drain, turn o󰀨 the appliance and close the
water supply line shut-o󰀨 valve. Locate and resolve the issue.
• Do not leave the appliance on during extended periods of non-use, extended
absences, or in sub-freezing temperatures. To properly prepare the appliance for
these occasions, follow the instructions in "VI. Preparing the Appliance for Periods of
Non-Use."
• Keep ventilation openings, in the appliance enclosure or in the built-in structure,
clear of obstruction.
• Do not place more than 33 lb. (15 kg) on the top panel.
• The storage bin is for ice use only. Do not store anything else in the storage bin.

6
I. Construction and Water/Refrigeration Circuit Diagram
A. Construction
Power Supply Cord
Rear Panel
Rear View (Outside)
Screw
Screw
Screw
Top Insulation
Top Panel
Bracket - Top Panel
Front Panel (Lower)
Bracket - Top Panel
Top Cover
Front View (Outside)

7
Fuse Holder
Control Switch
Evaporator Thermistor
Water Plate Switch
Evaporator
Pump Motor
Drain Pan
Inlet Water Valve
Bin Control
Control Box
Cam Switch
Scoop Holder
Ice Guide
Water Plate
Water Tank
Actuator Motor
Condenser Drier
Fan Motor
Hot Gas valve
Compressor
IM-50BAA-Q

8
IM-50BAA-LM
Fuse Holder
Control Switch
Evaporator Thermistor
Water Plate Evaporator
Pump Motor
Drain Pan
Inlet Water Valve
Bin Control
Control Box
Water Tank
Actuator Motor
Condenser
Drier
Fan Motor
Hot Gas valve
Compressor

9
B. Water/Refrigeration Circuit Diagram
Inlet
Water
Valve
Water
Pump
Drier
Condenser
Heat
Exchanger
Strainer
Hot Gas
Valve
Compressor
Water Tank
Accumulator
Evaporator
Fan Motor

10
II. Sequence of Operation and Service Diagnosis
A. Sequence of Operation Flow Chart
IM-50BAA-Q
Legend:
AMD–actuator motor down AMU–actuator motor up AT–ambient temperature
BC–bin control CBT–control board thermistor Comp–compressor
ET–evaporator thermistor FM–fan motor HGV–hot gas valve
PM–pump motor PS–position sensor WT–water temperature
WV–inlet water valve
2. Harvest Cycle
• Max. harvest time: 30 min.
3. Freeze Cycle
• Max. freeze time: 60 min. (CB Setting 6)
ET≤-4.9°F (-20.5°C)
(CB Setting 2)
Comp energized
FM energized
WV energized (*1)
PM energized
HGV energized (*1)
Comp energized
AMU energized
FM energized
WV energized
HGV energized
Water Tank Closed
(Actuator Motor PS)
Comp energized
AMD energized
FM energized
WV energized
PM energized
HGV de-energized
HGV energized
Startu
p
1. 30-Sec.
Startup
Cycle
Cycle
Steps
ET≥50°F (10°C)
(CB Setting 1)
Comp energized
FM de-energized
WV de-energized
HGV energized
Comp energized
FM energized
WV de-energized
PM energized
HGV de-energized
CB Setting 15 (*1)
[1] Ice formed on evaporator
When both water plate switch and cam switch turn on, AMD stops opening water tank on the way and Comp
de-energizes at the same time (for 5 min.).
WV stays energized to melt water tank bottom. FM is energized and HGV and PM are de-energized.
When either water plate switch or cam switch turns off, WV de-energizes and AMD starts opening water tank
fully.
[2] No ice formed on evaporator or ice formed on evaporator and high AT
Either water plate switch or cam switch turns off. AMD does not stop opening water tank and Comp stays
energized.
[3] Water tank opening by WT
WT≥55.4°F (13°C): Water tank starts opening again after 1 min.
WT<55.4°F (13°C): Water tank starts opening again after 5 min. WT is lower than 55.4°F (13°C) in initial cycle
after startup.
If water plate switch turns off within 1 or 5 min., water tank starts opening again.
[4] Harvest cycle with water tank open
1) When water tank opens and actuator motor PS indicates water tank is fully open, HGV energizes.
When 5 min. have passed after Comp de-energizes and actuator motor PS indicates water tank is fully open,
Comp energizes at the same time as above.
2) In [3], Comp stays energized. When actuator motor PS indicates water tank is fully closed, HGV energizes.
Water Tank Opens
AMD energized or de-energized
Comp energized
or de-energized
FM energized
WV energized
PM de-energized
HGV de-energized
WT≥55.4°F (13°C)
or
WT<55.4°F (13°C)
[1] [3]
[2]
Water Tank
Opens Again
Water Tank Stops
Opening
Water Tank Opened [4]
(Actuator Motor PS)
Shutdown
and Restart
BC Operation
1. Bin Full
BC open 10 sec. or
more (BC actuator
paddle engaged).
Shutdown occurs at
end of harvest cycle.
All components
de-energized.
BC closed 80 sec. or more
(BC actuator paddle
disengaged).
Icemaker restarts at
1. 30-Sec. Startup Cycle.
3. Ice Level Lowered 2. Icemaker Of
f
Shutdown and Restart Se
q
uence Flow Chart

11
IM-50BAA-LM
1. 30-Sec. Startup
Cycle
Legend:
AMD–actuator motor down AMU–actuator motor up BC–bin control
CBT–control board thermistor Comp–compressor ET–evaporator thermistor
FM–fan motor HGV–hot gas valve PM–pump motor
PS–position sensor WT–water temperature WV–inlet water valve
2. Harvest Cycle
• Max. harvest time: 30 min.
3. Freeze Cycle
• Max. freeze time: 90min. (CB Setting 6)
ET≤-20.2°F (-29.0°C)
(CB Setting 2)
Comp energized
AMU de-energized
FM energized
WV energized
PM de-energized
HGV de-energized
Comp energized
AMU energized
FM energized
WV energized
PM de-energized
HGV de-energized
HGV energized
Startu
p
1. 30-Sec.
Startup
Cycle
Cycle
Ste
p
s
ET≥50°F (10°C)
(CB Setting 1)
Shutdown and Restart Sequence Flow Chart
Shutdown
and Restart
BC Operation
1. Bin Full
All components
de-energized.
3. Ice Level
Lowered
2. Icemaker Of
f
Comp energized
AMD energized
FM de-energized
WV de-energized
PM de-energized
HGV energized
20 sec.
Comp energized
AMD energized
FM de-energized
WV energized
PM de-energized
HGV energized
Comp energized
AMD de-energized
FM de-energized
WV energized
PM de-energized
HGV energized
Water Tank Opened
(Actuator Motor PS)
Water Tank Closed
(Actuator Motor PS)
Comp energized
AMU de-energized
FM energized
WV energized
PM energized
HGV de-energized
Icemaker restarts at
1. 30-Sec. Startu
p
C
y
cle.
Comp energized
AMU de-energized
FM energized
WV energized
PM energized
HGV de-energized
WV: energized
WT<55.4°F (13°C): ET≥50°F (10°C)
(CB Setting 10)
WT≥55.4°F (13°C): 60sec.
(CB Setting 11)
WV: energized 24 sec.
(CB Setting 12)
WV: energized 10 sec.
(CB Setting N/A) WV: energized 12 sec.
(CB Setting 15)
WV: energized 12 sec.
(CB Setting 61)
BC open 50 sec. or more
(Ice is not pushing
BC actuator paddle).
BC closed 10 sec. or more.
(Ice is pushing BC actuator paddle).
Shutdown occurs at end of harvest cycle.

12
B. Sequence of Operation
IM-50BAA-Q
1. Startup Cycle
When power supply is turned on, "on" appears on CB display and HGV energizes.
30 seconds later, harvest cycle starts.
• If the "RESET" button is pressed during 30-second startup cycle time, startup cycle
ends immediately and harvest cycle starts.
Note: CB display "on" LED remains on unless the 24VDC power supply to CB CN1 is
interrupted.
2. Harvest Cycle
See the timing chart on page 14.
3. Freeze Cycle
See the timing chart on page 14.
4. Shutdown
When BC is engaged (open) for 10 seconds during the freeze cycle, the freeze cycle
and harvest cycle are continued as usual and then the icemaker shuts down after ET
temperature reaches harvest cycle termination temperature.
When BC disengaged (closed) for 50 seconds before ET temperature reaches harvest
cycle termination temperature, as usual and harvest cycle starts as usual and continue
the operation.
If BC engaged (open) for 10 seconds while AMU energizes, see the timing chart on page
14.
If BC engaged (open) for 10 seconds while AMD energizes, see the timing chart on page
14.
Legend: AMD–actuator motor down; AMU–actuator motor up; BC–bin control; CB-control
board; CBT–control board thermistor; ET–evaporator thermistor; HGV–hot gas
valve

13
IM-50BAA-LM
1. Startup Cycle
When power supply is turned on, "on" appears on CB display and HGV energizes. 30
seconds later, harvest cycle starts.
• If the "RESET" button is pressed during 30-sec. startup cycle time, startup cycle ends
immediately and harvest cycle starts.
Note: CB display "on" LED remains on unless the 24VDC power supply to CB CN1 is
interrupted.
2. Harvest Cycle
When WT is below 55.4°F (13°C), WV energizes until ET reaches 50°F (10°C). When
WT is 55.4°F (13°C) or higher, WV energizes for 60 seconds. See the timing chart on
page 15.
3. Freeze Cycle
WV energizes for 24 seconds after freeze cycle starts. (PM starts operation at the same
time.) Then, WV energizes for 12 seconds after PM starts operation, and re-energizes
for 12 seconds after freeze cycle termination rate reaches 30%. See the timing chart on
page 15.
4. Shutdown
When BC is engaged (open) for 10 seconds during freeze cycle, freeze cycle continues
and harvest cycle starts as usual. After ET temperature reaches harvest cycle termination
temperature, shutdown occurs.
When BC is disengaged (closed) for 50 seconds before ET temperature reaches harvest
cycle termination temperature, harvest cycle starts as usual and operation continues.
If BC is engaged (open) for 10 seconds while AMU energizes, see the timing chart on
page 15.
If BC is engaged (open) for 10 seconds while AMD energizes, see the timing chart on
page 15.
Legend: AMD–actuator motor down; AMU–actuator motor up; BC–bin control; CB–
control board; ET–evaporator thermistor; HGV–hot gas valve; WV–inlet water
valve; PM–pump motor

14
State 1 4 6 7 8 1 2 6 7 1 2 1 2
ON
OFF
ON
OFF
ON *1 *1 *1
OFF
15 sec *2 15 sec *2 *2
ON
OFF
15 sec 15 sec
ON
OFF
Hi
g
h
Lo
w
OFF 50 sec
Hi
g
h
Lo
w
OFF
ON
OFF
100%
60% 30%
0%
7-Segment Display Operation
State 0 When power supply is turned on at startup, hot gas valve energizes. After 30 seconds, State 1 starts. State 1 After compressor energizes at startup or freeze cycle ends, water tank opens until cam switch detects cam location while water is supplied for harvest cycle.
If evaporator has no ice, water plate switch turns off, compressor keeps running, and water tank fully opens. * The above operation is also made at high ambient temperatures where ice is easy to harvest.
State 2 If freeze c
y
cle ends and eva
p
orator has ice, water tank o
p
ens until cam switch detects cam location, but water
p
late does not se
p
arate, and actuator moto
r
and compressor de-energize (*1).
State 3 When water plate switch turns off, inlet water valve de-energizes and water tank starts to open again.
If water temperature is 55.4°F (13°C) or higher, water tank starts to open again in 1 minute (*2). If water temperature is lower than 55.4°F (13°C), water tank starts to open again in 5 minutes (*2). --- Water temperature is
lower than 55.4°F (13°C) in initial cycle after startup. However, if water plate switch turns off within 1 or 5 minute(s), water tank starts to open again. * When water
p
late switch or cam switch turns off, water tank starts to o
p
en a
g
ain
.
State 4 When water tank opens and actuator motor's internal position sensor indicates water tank is fully open, hot gas valve energizes.
When 5 minutes have passed after compressor de-energizes in State 2 and actuator motor's internal position sensor indicates water tank is fully open,
compressor energizes (*3).
State 5 When evaporator thermistor temperature reaches harvest cycle termination temperature, water tank starts to close and inlet water valve energizes to start
water supply. Fan motor energizes at the same time.
State 6 When water tank closes and actuator motor's internal position sensor indicates water tank is fully closed, pump motor energizes, and inlet water valve and hot
gas valve energizes for 15 seconds.
State 7 After 15 seconds, inlet water valve and hot gas valve de-energizes to start freeze cycle. State 8 When evaporator thermistor reaches target integrated value, State 1 starts (see details).
Harvest Cycle - Bin Control (1): Bin control while water tank is closing
State 5 Bin control trips while water tank is closing. After 10 seconds, water tank starts to open again, and actuator motor's internal position sensor indicates water tank is fully open. Then, icemaker shuts down.
(When bin control is ON for 10 seconds, inlet water valve de-energizes. Then, after water tank fully opens, compressor and hot gas valve de-energize.)
When bin control is ON for 50 seconds, hot gas valve energizes. When bin control is ON for 80 seconds, State 5 in harvest cycle - normal starts followed by freeze cycle.
Harvest Cycle - Bin Control (2): Bin control after water tank opens
State 5 Water tank opens and actuator motor's internal position sensor indicates water tank is fully open. When bin control trips, water tank does not close even if harvest cycle termination temperature is reached.
After 10 seconds, icemaker shuts down. When bin control is ON for 50 seconds, hot gas valve energizes. When bin control is ON for 80 seconds, State 5 in harvest cycle - normal starts followed by freeze cycle.
Freeze Cycle Termination Rate Evaporator Thermistor Temp. Bin Control Switch Inlet Water Valve Actuator Motor
Close
OFF
Open
Hot Gas Valve Pump Motor Fan Motor
34 5
Water Plate Switch Cam Switch Compressor 30 sec
Harvest Cycle - Bin Control (2)
0 3 5 3 4 5 34 5
Startup Initial Cycle Freeze Cycle Harvest Cycle - Normal Freeze Cycle Harvest Cycle - Bin Control (1)
Freeze Cycle Termination Temp.
Harvest Cycle Termination Temp.
32°F(0°C)
*3 *3 *3
10 sec 10 sec
80 sec
50 sec
80 sec
50 sec
1) Target integrated value for freeze cycle termination is determined by
CB Settings 2 and 3.
2) After evaporator thermistor senses 32°F (0°C), freeze cycle termination
temperature and freeze cycle termination time are integrated ev
ery second.
3) When target integrated value is reached, freeze cycle ends.
State 8 (details)
IM-50BAA-Q

15
IM-50BAA-LM
State 0 1 3 5 1 5 12 12 3 04 12 0 5
ON
OFF
ON
OFF
ON
OFF
HIGH
LOW
OFF
HIGH
LOW
OFF
ON
OFF
Evaporator Thermistor Temp
100%
60% 30%
0%
7-Segment Display O
p
eration
State 0 State 1 State 2
State 3 State 4
State 5 State 6 State 7 State 8 State 1 State 4 State 1 State 2 Water valve energizes for a specified time 20 seconds after actuator motor down starts
.
State 3 State 2 State 3 State 4
Harvest Cycle - Bin Control (2)
34
Harvest Cycle Freeze Cycle
Freeze Cycle Termination Rate Fan Motor
4
Compressor
434 463822
Harvest Cycle - Bin Control (1)
7
Startup Initial Cycle
Water Valve Actuator Motor
Close
OFF
Open
6
Freeze Cycle
30 sec
Bin Control Switch Hot Gas Valve Pump Motor
After bin control switch is OFF for 50 seconds, State 1 starts. Bin control switch is ON for 10 seconds while actuator motor up is energized.
Harvest Cycle - Bin Control (1): Bin control while actuator motor up is energized
3) When integrated value reaches set target value, freeze cycle terminates. Pump motor and fan motor de-energize, and hot gas valve and actuator motor down energize. Actuator motor down energizes, fan motor de-energizes and hot gas valve energizes. When actuator motor down de-energizes, compressor, water valve and hot gas valve de-energize, and icemaker shuts down. When power supply is turned on at startup, hot gas valve energizes. After 30 seconds, State 1 starts. Hot gas valve stays energized, and actuator motor down energizes. Water valve energizes for a specified time 20 seconds after actuator motor down starts. Freeze cycle termination rate (target corresponding value) 1) In maintenance mode, enter target integrated value (evaporator thermistor temperature and freeze cycle time) for freeze cycle termination. 2) Evaporator thermistor temperature and freeze cycle time are integrated every second after evaporator thermistor temperature reaches 32°F (0°C).
*1: If evaporator temperature is below 55.4°F (13°C), water is supplied until evaporator temperature reaches harvest cycle termination temperature of 50°F (10°C).
*2: If evaporator temperature is 55.4°F (13°C) or higher, water is supplied for 60 seconds When freeze cycle termination rate (target corresponding value) reaches 100%, hot gas valve energizes for 10 seconds and de-energizes for 20 seconds, which is repeated once more. Bin control switch is ON for 10 seconds while actuator motor down, water valve and hot gas valve are energized. Actuator motor down de-energizes, and water valve and hot gas valve stay energized. After bin control switch is OFF for 50 seconds, State 1 starts.
Harvest Cycle - Bin Control (2): Bin control while actuator motor down is energized
When freeze thermistor temperature reaches harvest cycle termination temperature, compressor, water valve and hot gas valve de-energize, and icemaker shuts down. Hot gas valve stays energized, and actuator motor down de-energizes. When evaporator thermistor temperature reaches harvest cycle termination temperature, hot gas valve de-energizes, actuator motor up and fan motor energize, and water valve energizes for 10 seconds. Actuator motor up de-energizes, and water valve energizes for 24 seconds. After water valve energizes for 24 seconds, pump motor energizes, and then water valve energizes again for 12 seconds. When freeze cycle termination rate (target corresponding value) reaches 30%, water valve energizes for 12 seconds.
Freeze Cycle Termination Temp.
Harvest Cycle Termination Temp.
0ºC
10 sec
24
sec
24 sec
20 sec 12 sec 20
sec 60 sec *2 *1 10
sec
12 sec
12 sec 20
sec
10 sec
24 sec
20 sec
60 sec
*2
10 sec
20 sec
*1
60 sec *2 *1
10 sec
20 sec
30 sec 30
sec
10 sec 50
sec
50 sec
10 sec
State 8 (details)

16
C. Service Diagnosis Table
First see "III.G. Error Codes." If there are no recorded errors, refer to the table below.
No Ice Production - Possible Cause
1. Power Supply a) O󰀨, blown fuse, or tripped breaker.
b) Not within specications.
2. Fuse (Control Box) a) Blown.
3. Control Switch a) In "OFF" or "WASH" position.
b) Bad contacts.
4. Control Board a) Error. See "III.G. Error Codes."
b) Defective.
5. Bin Control
See "II.D. Bin Control Check and
Cleaning"
a) Tripped with bin lled with ice.
b) Actuator does not move freely.
c) Defective.
6. Water Supply a) Water supply o󰀨 or improper water pressure.
b) External water lters restricted.
7. Inlet Water Valve a) Screen or orice restricted.
b) Coil winding open.
8. Compressor a) Compressor relay/magnetic contactor contacts bad or coil winding
open.
b) Start capacitor or run capacitor defective (single phase).
c) Internal protector open.
d) Start relay contacts bad or coil winding open (single phase).
e) Defective.
9. Hot Gas Valve a) Defective.
10. Evaporator (Cube Control)
Thermistor
See "II.E. Evaporator Thermistor
Check"
a) Loose, disconnected, or defective.
11. Pump Motor a) Defective.
12. Thermostatic Expansion Valve a) Bulb loose.
b) Defective.
13. Fan Motor a) Defective.
14. Water System a) Water leaks.
Low Ice Production - Possible Cause
Long Harvest Cycle
1. Evaporator a) Scaled up.
2. Refrigerant Charge a) Low.
3. Control Board a) Thermistor connection loose (K3).
b) Defective.
4. Evaporator (Cube Control)
Thermistor
See "II.E. Evaporator Thermistor
Check"
a) Loose, disconnected, or defective.
5. Hot Gas Valve a) Erratic or closed.
6. Compressor a) Ine󰀩cient or o󰀨.

17
Long Freeze Cycle
1. Evaporator a) Scaled up, dirty.
2. Hot Gas Valve a) Defective.
3. Condenser a) Restricted.
4. Control Board a) Defective.
5. Refrigerant Charge a) Low.
6. Compressor a) Ine󰀩cient or o󰀨.
Slab Does Not Break Into Separate Cubes - Possible Cause
1. Spring a) Over-extended.
2. Water Plate a) Obstacle caught between evaporator and water plate.
Cubes Drop Separately - Possible Cause
1. Refrigerant Charge a) Low - Long harvest cycle.
2. Cam Arm a) Worn out.
Imperfect Ice Production - Possible Cause
1. Water Supply a) Improper water pressure.
b) External water lters restricted.
c) Water leaks from water tank or water plate due to broken tank or
plate or icemaker out of level.
2. Inlet Water Valve a) Water leaks from valve body or water supply pipe joint.
3. Water Plate a) Spray holes restricted.
4. Pump Motor a) Defective.
Large-Hole Cubes - Possible Cause
1. Refrigerant Charge a) Low.
2. Condenser a) Dirty condenser or air lter.
3. Fan Motor a) Defective.
4. Icemaker Location a) Insu󰀩cient clearance.
b) Ambient temperature too high.
5. Water Supply a) Water leaks.
b) Improper water pressure.
Cloudy Cubes - Possible Cause
1. Water Quality a) High hardness.
2. Slush Ice a) Use Anti-Slush Control (Control Board Settings 50 and 51).

18
D. Bin Control Check and Cleaning
1. Bin Control Check
IM-50BAA-Q
This appliance uses a lever-actuated proximity switch to control the ice level in the
storage bin. No adjustment is required.
To check, follow the steps below.
1) Remove the front panel and then move the control switch to the "OFF" position.
2) Unplug the appliance.
3) Remove the control box cover. Clear any ice away from BC.
4) Check BC wire harness connections.
5) Disconnect BC wire harness connector from CB CN3 connector.
6) Check for continuity across the wires of BC wire harness connector. When the actuator
paddle is not engaged, BC switch is closed. If open, check that the wire harness
connector is properly connected and that the actuator paddle is not sticking. Clean if
necessary. See "II.D.2. Bin Control Cleaning." If BC switch still reads open, replace BC.
7) Press and hold the actuator paddle; check for continuity across the wires of BC wire
harness connector. When the actuator paddle is engaged, BC switch is open. If closed,
check that the actuator paddle is not restricted. Clean if necessary. See "II.D.2. Bin
Control Cleaning." If BC switch still reads closed, replace BC.
8) Reconnect BC wire harness connector to CB CN3 connector, then move the control
switch to the "ICE" position. Turn on the power supply.
9) Allow the icemaker to cycle on. Press and hold the actuator paddle for at least
10 seconds. The icemaker should shut down. If it does not, replace CB.
Note: If BC is engaged (open) while the water tank is opening after the power supply
is turned on (or after the "RESET" button is pressed), shutdown does not start:
Shutdown occurs 10 seconds after actuator motor's internal position sensor
indicates water tank is fully open.
Legend: BC–bin control; CB–control board
Fig. 1
Bin Control Cable Connector
Actuator Paddle
Switch Mount
Magnet
Thumbscrew
Bin Control Bracket
Bin Control

19
IM-50BAA-LM
This appliance uses a lever-actuated microswitch to control the ice level in the storage
bin. No adjustment is required.
To check, follow the steps below.
1) Remove the front panel and then move the control switch to the "OFF" position.
2) Unplug the appliance.
3) Remove the control box cover. Clear any ice away from BC.
4) Check BC wire harness connections.
5) Disconnect BC wire harness connector from CB CN3 connector.
6) Check for continuity across the wires of BC wire harness connector. When the actuator
paddle is vertical, BC microswitch contact is open. When the actuator paddle is pushed
(tilted) in the moving direction, BC microswitch contact closes.
7) Check that the actuator paddle is not sticking. Clean if necessary. See "II.D.2. Bin
Control Cleaning." If BC microswitch contact still does not open/close, replace BC.
8) Reconnect BC wire harness connector to CB CN3 connector, and plug in the appliance.
Then, move the control switch on the control box to the "ICE" position.
9) The icemaker starts operation after 30 seconds. Press and hold (tilt) the actuator
paddle in the moving direction for 10 seconds. The icemaker should shut down. If it
does not, replace CB.
Legend: BC–bin control; CB–control board
BC microswitch contact: Close
(Control board input signal: ON)
BC microswitch contact: Open
(Control board input signal: OFF)
Running Stop