Hoshizaki KM-2500SRH3 User manual

Hoshizaki
“A Superior Degree
of Reliability”
www.hoshizaki.com
Models
KM-2500SWH3
KM-2500SRH3
Stackable Crescent Cuber
Hoshizaki America, Inc.
Number: 73164
Issued: 6-10-2010
SERVICE MANUAL
™

2
IMPORTANT
Only qualied 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 qualied 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 30269
Attn: Hoshizaki Technical Support Department
Phone: [phone] Technical Support
[phone]
Fax: [phone]
[phone]
E-mail: [email protected]
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. 

3
IMPORTANT
This manual should be read carefully before the icemaker is serviced or
maintenance operations are performed. Only qualied 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 ................................................................................................. 5
I. Specications...................................................................................................................... 6
A. Icemaker ....................................................................................................................... 6
1. KM-2500SWH3 (water-cooled) ................................................................................ 6
2. KM-2500SRH3 (remote air-cooled) ......................................................................... 7
B. Condenser Unit ............................................................................................................. 8
1. URC-23F.................................................................................................................. 8
II. General Information ......................................................................................................... 10
A. Construction................................................................................................................ 10
1. KM-2500SWH3 (water-cooled) .............................................................................. 10
2. KM-2500SRH3 (remote air-cooled) ........................................................................11
B. Sequence of Operation ............................................................................................... 12
1. Sequence Cycles and Shutdown ........................................................................... 12
a) 1-Minute Fill Cycle ........................................................................................... 12
b) Initial Harvest Cycle ........................................................................................ 12
c) Freeze Cycle ................................................................................................... 12
d) Pump-Out Cycle .............................................................................................. 12
e) Harvest Cycle .................................................................................................. 13
f) Shutdown.......................................................................................................... 13
2. Sequence Flow Chart............................................................................................ 14
C. Control Board .............................................................................................................. 15
1. Control Board Layout ............................................................................................. 16
2. 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
3. LED Lights and Audible Alarm Safeties ................................................................. 18
4. Controls and Adjustments...................................................................................... 19
a) Default Dip Switch Settings.............................................................................. 19
b) Harvest Timer (S4 dip switch 1 & 2)................................................................. 19
c) Pump-Out Timer (S4 dip switch 3 & 4)............................................................. 20
d) Pump-Out Frequency Control (S4 dip switch 5 & 6)......................................... 20
e) Bin Control Selector (S4 dip switch 7).............................................................. 21
f) Factory Use (S4 dip switch 8) ........................................................................... 21
g) Freeze Timer (S4 dip switch 9 & 10) ................................................................ 21

4
D. Bin Control .................................................................................................................. 22
E. Float Switch................................................................................................................. 22
F. Thermistor.................................................................................................................... 22
G. Control Switch............................................................................................................. 22
III. Technical Information ...................................................................................................... 23
A. Water Circuit and Refrigeration Circuit ........................................................................ 23
1. KM-2500SWH3 (water-cooled) .............................................................................. 23
2. KM-2500SRH3 (remote air-cooled) ....................................................................... 24
B. Wiring Diagrams.......................................................................................................... 25
1. KM-2500SWH3 (water-cooled), KM-2500SRH3 (remote air-cooled) ..................... 25
C. Performance Data ....................................................................................................... 26
1. KM-2500SWH3 (water-cooled) .............................................................................. 26
2. KM-2500SRH3 (remote air-cooled) ....................................................................... 27
IV. Service Diagnosis ........................................................................................................... 28
A. Diagnostic Procedure ................................................................................................. 28
B. Control Board Check ................................................................................................... 31
C. Bin Control Check ....................................................................................................... 32
D. Float Switch Check and Cleaning ............................................................................... 32
E. Thermistor Check........................................................................................................ 34
F. Diagnostic Charts ........................................................................................................ 35
V. Removal and Replacement of Components .................................................................... 43
A. Service for Refrigerant Lines....................................................................................... 43
1. Refrigerant Recovery ............................................................................................. 43
2. Brazing .................................................................................................................. 44
3. Evacuation and Recharge (R-404A)...................................................................... 44
B. Removal and Replacement of Compressor................................................................. 45
C. Removal and Replacement of Expansion Valve.......................................................... 46
D. Removal and Replacement of Hot Gas Valve or Liquid Line Valve ............................. 47
E. Removal and Replacement of Evaporator................................................................... 48
F. Removal and Replacement of Water-Cooled Condenser............................................. 49
G. Removal and Replacement of Remote Air-Cooled Condenser ................................... 50
H. Removal and Replacement of Water Regulating Valve (water-cooled model)............. 51
I. Adjustment of Water Regulating Valve - Water-Cooled Model ...................................... 52
J. Removal and Replacement of Headmaster (Condensing Pressure Regulator - C.P.R.) -
Remote Air-Cooled Model ......................................................................................... 52
K. Removal and Replacement of Thermistor................................................................... 53
L. Removal and Replacement of Fan Motor – Remote Air-Cooled Model........................ 54
M. Removal and Replacement of Inlet Water Valve ......................................................... 54
N. Removal and Replacement of Pump Motor ................................................................ 55
O. Removal and Replacement of Control Board.............................................................. 56
VI. Cleaning and Maintenance............................................................................................. 57
A. Cleaning and Sanitizing Instructions ........................................................................... 57
1. Cleaning Procedure................................................................................................ 58
2. Sanitizing Procedure - Following Cleaning Procedure ........................................... 59
B. Maintenance................................................................................................................ 60
C. Preparing the Icemaker for Long Storage ................................................................... 60

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qualied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. Specications
A. Icemaker
1. KM-2500SWH3 (water-cooled)
Note: We reserve the right to make changes in specications and design without prior
notice.
AC SUPPLY VOLTAGE 208-230/60/3
AMPERAGE 14.2 A ( 5 Min. Freeze AT 104°F / WT 80°F)
MINIMUM CIRCUIT AMPACITY 30 A
MAXIMUM FUSE SIZE 30 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp.(°F) 50 70 90
lbs./day ( kg/day ) 70 *2408 (1092) 2395 (1087) 2256 (1024)
Reference without *marks 80 2398 (1088) 2379 (1079) 2172 (985)
90 2395 (1087) *2365 (1073) 2184 (991)
100 2327 (1055) 2323 (1054) 2018 (915)
SHAPE OF ICE Crescent Cube
ICE PRODUCTION PER CYCLE 46.3 lbs. (21 kg) 2160pcs.
APPROXIMATE STORAGE CAPACITY N/A
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 3720(3.78) 3510(3.5)
WATER gal./24HR (gal./100 lbs.) 459(19.4) 744(30.9)
WATER COOLED CONDENSER 1430(101) 1430(59)
gal./24HR (gal./100 lbs.)
CEC/CEE TIER LEVEL 1
ENERGY STAR N/A
EXTERIOR DIMENSIONS (WxDxH) 48" x 27-3/8" x 36-7/16" (1219 x 695 x 925 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT Net 390 lbs. (177 kg), Shipping 415 lbs. (188 kg)
CONNECTIONS - ELECTRIC Permanent - Connection
- WATER SUPPLY Inlet 1/2" FPT Condenser Inlet 1/2" FPT
- DRAIN Outlet 3/4" FPT Condenser Outlet 1/2" FPT
3/8" 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 Thermostat
COMPRESSOR Hermetic, Model CS27K6E-TF5-237
CONDENSER Water Cooled, Tube in Tube Type
EVAPORATOR Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL Thermostatic Expansion Valve
REFRIGERANT CHARGE R404A, 4 lb. 11.5 oz. (2140g)
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 Storage Bin
OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 V
AMBIENT TEMP. 45 -100° F
WATER SUPPLY TEMP. 45 - 90° F
WATER SUPPLY PRESSURE 10 - 113 PSIG
ENG.F-011.1.0205

7
2. KM-2500SRH3 (remote air-cooled)
Note: We reserve the right to make changes in specications and design without prior
notice.
AC SUPPLY VOLTAGE 208-230/60/3
AMPERAGE 17.7 A ( 5 Min. Freeze AT 104°F / WT 80°F)
MINIMUM CIRCUIT AMPACITY 30 A
MAXIMUM FUSE SIZE 30 A
APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F)
PER 24 HR. Temp.(°F) 50 70 90
lbs./day ( kg/day ) 70 *2424 (1100) 2373 (1076) 2196 (996)
Reference without *marks 80 2385 (1082) 2306 (1046) 2069 (939)
90 2373 (1076) *2250 (1021) 2035 (923)
100 2301 (1044) 2200 (998) 1837 (833)
SHAPE OF ICE Crescent Cube
ICE PRODUCTION PER CYCLE 46.1 lbs. (20.9 kg) 2160pcs.
APPROXIMATE STORAGE CAPACITY N/A
ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F
ELECTRIC W (kWH/100 lbs.) 4220(4.5) 3780(3.7)
WATER gal./24HR (gal./100 lbs.) 419(18.6) 791(32.6)
CEC/CEE TIER LEVEL 2
ENERGY STAR YES
EXTERIOR DIMENSIONS (WxDxH) 48" x 27-3/8" x 36-7/16" (1219 x 695 x 925 mm)
EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear)
WEIGHT Net 390 lbs. (177 kg), Shipping 440 lbs. (200 kg)
CONNECTIONS - ELECTRIC Permanent - Connection
- WATER SUPPLY Inlet 1/2" FPT
- DRAIN Outlet 3/4" FPT
3/8" 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 Thermostat
COMPRESSOR Hermetic, Model MTZ-57-HL3A
CONDENSER Air-Cooled Remote, Condenser Unit URC-23F
EVAPORATOR Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL Thermostatic Expansion Valve
Condensing Pressure Regulator on Icemaker (190 PSI)
REFRIGERANT CHARGE R404A, 24 lb. 7.5 oz. (11100g)
(Icemaker 14 lbs. 12.3 oz. Cond. Unit 9 lbs. 11.2 oz.)
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 Storage Bin, Remote Condenser Unit
OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 V
AMBIENT TEMP. 45 -100° F
WATER SUPPLY TEMP. 45 - 90° F
WATER SUPPLY PRESSURE 10 - 113 PSIG
ENG.F-011.1.0205

8
B. Condenser Unit
1. URC-23F
Note: We reserve the right to make changes in specications and design without prior
notice.
Unit: mm (inches)

9
SPECIFICATIONS
MODEL: URC-23F
AC SUPPLY VOLTAGE 115/60/1 (Connection to Icemaker)
FAN MOTOR 115 V Total 2.6FLA 130W
EXTERIOR DIMENSIONS (WxDxH) 46-3/8" x 15-11/16" x 25-15/16" (1178 x 398 x 659 mm)
DIMENSIONS INCLUDING LEGS (WxDxH) 48-7/16" x 18-1/8" x 40-7/8" (1230 x 460 x 1039 mm)
EXTERIOR FINISH Galvanized Steel
WEIGHT Net 158 lbs. ( 72 kg ) Shipping 169 lbs. ( 77 kg )
CONNECTIONS - ELECTRIC Permanent - Connection
- REFRIGERANT Discharge Line 1-1/16"-12 UNF Fitting (#10 AEROQUIP)
Liquid Line 5/8"-18 UNF Fitting (#6 AEROQUIP)
CONDENSER Air-cooled, Fin and tube type
FAN MOTOR PROTECTION Thermal Protection
REFRIGERANT CONTROL Condensing Pressure Regulator (In Ice Machine)
REFRIGERANT CHARGE R-404A 9 lb. 11oz. (4400g)
DESIGN PRESSURE High 467 PSIG 32.2 Bar
OPERATING CONDITIONS VOLTAGE RANGE 104 ~ 127 V
AMBIENT TEMP. -20 ~ 122 °F
ACCESSORIES -SUPPLIED Leg 2 pcs
Hex. Head Bolt w/Washer 8 x 16 8 pcs
Hex. Nut 8 8 pcs
Note: We reserve the right to make changes in specications and design without prior
notice.

10
II. General Information
A. Construction
1. KM-2500SWH3 (water-cooled)
Main Transformer
Box
Evaporator Assembly
Spray Tubes
Inlet Water Valve Water Supply Inlet
Hot Gas Valve
Junction Box
Water
Regulating
Valve
Service Valves
Control Box
Liquid Line Valve
Drier
Control Switch
Bin Control Thermostat
Compressor
Cleaning Valve
Float Switch
Water Pump
Check Valve
(water)
Expansion Valves
Strainer
Bin Control Thermostat Bracket
Bin Control Bulb Holder
Check Valves
(Refrigeration Circuit)
Condenser
Bin Control "Z" Bracket
Bin Control Extension Bracket

11
2. KM-2500SRH3 (remote air-cooled)
Evaporator Assembly
Spray Tubes
Inlet Water Valve Water Supply Inlet
Hot Gas Valve
Junction Boxes
Receiver Tank
Service Valves
Control Box
Liquid Line Valve
Drier
Main Transformer
Box
Control Switch
Bin Control Thermostat
Compressor
Cleaning Valve
Float Switch
Water Pump
Check Valve
(water)
Expansion Valves
Strainer
Shut-Off Valve
(Factory Use Only)
Headmaster
(C.P.R.)
Check Valves
(Refrigeration Circuit)
Bin Control Thermostat Bracket
Bin Control Bulb Holder
Bin Control "Z" Bracket
Bin Control Extension Bracket

12
B. Sequence of Operation
1. Sequence Cycles and Shutdown
The steps in the sequence are as outlined below. When power is supplied and BC is
closed, CB red "POWER OK" LED comes on. There is a 5-second delay before startup.
Note that the order of the LEDs from the outer edge of CB is 1, 4, 3, 2.
a) 1-Minute Fill Cycle
LED 4 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 enters the tank and closes F/S. This
serves as a low water safety to protect PM.
b) Initial Harvest Cycle
LEDs 1, 4, and 2 are on. WV remains energized, Comp, FMR, and HGV energize.
CBmonitors the warming of the evaporator via the thermistor located on the suction line.
When the thermistor warms to 48°F (9°C), CB reads a 3.9 kΩ signal from the thermistor
and turns harvest termination over to the harvest timer (S4 dip switch 1 & 2) which is
factory set for normal conditions. The harvest timer has settings of 60, 90, 120, and 180
seconds. For details, see "II.C.4.b) Harvest Timer (S4 Dip Switch 1 & 2)." When the
harvest timer terminates, the harvest cycle is complete. At the end of harvest, CB checks
the position of F/S and proceeds to the next 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
2minutes. WV is energized during harvest for a maximum of 6 minutes or the length of
harvest, whichever is shorter.
c) Freeze Cycle
LED 1 is on. Comp and FMR remain energized. PM and LLV energize. HGV and WV
de-energize. For the rst 5 minutes, CB will not accept a signal from F/S. This 5-minute
minimum freeze time is short cycle protection for Comp. At the end of 5minutes, F/S
assumes control of freeze termination. As ice builds on the evaporator, the water level
in the tank lowers. The freeze cycle continues until F/S opens, then CB terminates the
freeze cycle.
d) Pump-Out Cycle
LEDs 1, 3, and 2 are on. LED 4 is on when S4 dip switch 3 & 4 are set to 3 off and 4on.
Comp and FMR remain energized. HGV energizes, LLV de-energizes. WV energizes
if S4 dip switch 3 & 4 are set to 3 off and 4 on. PM stops for 2 seconds then reverses,
taking water from the bottom of the tank and forcing pressure against the check valve
seat allowing water to go through the check valve and down the drain. At the same time,
water ows through the small F/S tube to power ush F/S. When the pump-out timer (S4
dip switch 3 & 4) terminates, pump-out is complete.
The rst pump-out occurs after the rst freeze cycle and every cycle thereafter. The
pump-out frequency control is factory set to drain the water tank every cycle, and
generally no adjustment is required. The pump-out frequency control (S4 dip switch 5
& 6) can be set to have a pump out occur every cycle, or every 2, 5, or 10 cycles. For
details, see "II.C.4.d) Pump-Out Frequency Control (S4 Dip Switch 5& 6)."

13
e) Harvest Cycle
Same as the initial harvest cycle. See "II.B.1.b) Initial Harvest Cycle."
Note: Unit continues to cycle until BC is satised or power is turned off. The unit always
restarts at the 1-minute ll cycle.
f) Shutdown
When ice contacts the thermostatic bulb (BC switch open), BC shuts down the unit within
10 seconds. BC is factory set, and generally no adjustment is required. However,
adjustment may be needed in some conditions, particularly at higher altitude
locations. CAUTION! Do not adjust S4 dip switch 7 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.
Legend: BC–bin control; CB–control board; Comp–compressor; FMR–fan
motor-remote; F/S–oat switch; HGV–hot gas valve; LLV –liquid line valve;
PM–pump motor; WV–inlet water valve

14
2. Sequence Flow Chart
"E" Control Board Sequence Flow Chart
KM-2500SWH3, KM-2500SRH3
Startup begins here after 5-sec. delay
4. Pump-Out Cycle
•Factorysetforevery
cycle (S4 dip switch 5 & 6)
•Pumpmotorstopsfor
2 sec., then reverses for 10/20 sec. (S4 dip switch 3 & 4)
F/S Check
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.
Legend: Comp–compressor FMR–fan motor-remote F/S–oat switch HGV–hot gas valve LLV –liquid line valve PM–pump motor TBC–thermostatic bin control WV–inlet water valve
1. 1-Minute Fill
Cycle
2. Harvest Cycle 3. Freeze Cycle
WV energized
F/S open
F/S closed
WV continues Comp energized FMR energized HGV energized
Thermistor temp warms to 48°F (9°C) (3.9 kΩ or less) Harvest timer starts
F/S open
Comp continues FMR continues LLV energized PM energized HGV de-energized WV de-energized
F/S closed
F/S Check
•WVtime:6min.orthelengthofharvest,
whichever is shorter.
•Maximumharvesttime:20min.
Thermistor in control 1 to 3-min. timer in control
(S4 dip switch 1 & 2)
•Minimumfreezetime:5min. •Maximumfreezetime:freezetimersetting
(S4 dip switch 9 & 10
5-min. timer in control
F/S in control
If F/S is open, compressor stops and cycle returns to 1-Minute Fill Cycle
1. Bin Full Unit shuts down within 10 sec. after ice contacts thermostatic bulb.
Shutdown and Restart
TBC Operation
Ice contacts thermostatic bulb
2. Icemaker Off All components de-energized.
3. Ice Level Lowered Ice level lowered. No ice touching thermostatic bulb. Icemaker starts at "1. 1-Minute Fill Cycle."
TBC closed
TBC open All components de-energized
To 1 above
Comp continues FMR continues HGV energized WV energized if dip switch 3& 4 set to 3 off and 4on. LLV de-energized PM de-energizes for 2 sec., then reverses for 10/20 sec.
F/S open or freeze timer expires
Cycle Steps

15
C. Control Board
•AHoshizakiexclusivecontrolboardisemployedinKM-2500SWH3andKM-2500SRH3
Stackable Crescent Cubers.
•Allmodelsarepretestedandfactory-adjusted.
•Foracontrolboardcheckprocedure,see"IV.B.ControlBoardCheck."
CAUTION
1. The control board is fragile; handle very carefully.
2. 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. Do not misconnect K3, K4, and K5,
because the same connector is used for the thermistor and oat switch. K4 is
not connected.
5. Always replace the whole control board assembly if it goes bad.
6. Do not short out power supply to test for voltage.

16
"E" Control Board
1. Control Board Layout
"E" Control Board
Part Number 2A1410-01 (factory); 2A1410-02 (service)
• "OUTPUT TEST" Button
(used to test relays on control board)
• WHITE K3 Connector
Harvest Control
(thermistor)
• RED K4 Connector
Open (not connected)
• Microprocessor
(control board
revision level
indicated by last 2
digits on label)
• BLACK K5 Connector
Float Switch
• Part Number
• K1 Ten-Pin Connector
Pins #1 through #10
#1, 9 Magnetic Contactor (CR)
Fan Motor-Remote (FMR)
#2 Hot Gas Valve (HGV)
#3 Fan Motor (FM)
Liquid Line Valve (LLV)
#4 Pump Motor (icemaking)
#5 Pump Motor (pump-out)
#6 Inlet Water Valve (WV)
#7, 10 Component Power
Supply
#8 Open
• Switch for "C" Control Board
and "ALPINE" Control Board
(service boards only)
• "ALARM RESET" Button
•"F TIMER"
Freeze Timer LED
• S4 Dip Switch
• "H TIMER"
Harvest Backup
Timer LED
• Alarm Buzzer
• "Power OK" LED
(red) (lights when
power is supplied to
the control board)
• LED 2 (X2 Relay)
Hot Gas Valve (HGV)
Fan Motor (FM) (FM
off when LED on)
• LED 3 (X3 Relay)
Pump Motor (PM)
(on at pump-out only)
• LED 4 (X4 Relay)
Inlet Water Valve (WV)
• LED 1 (X1 Relay)
Compressor
(Comp)
Fan Motor-Remote
(FMR)
• K2 Connector
Transformer
• Relay LEDs (4)
(indicate which relays
are energized as
listed below)

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2. Features
a) Maximum Water Supply Period – 6 minutes
The inlet water valve remains energized during harvest for 6 minutes or the length of
harvest whichever is shorter.
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 20 minutes to complete. The control board signals with the
"HTimer" LED and 2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 specied by the freeze timer (S4 dip switch 9 & 10). The
control board signals with the "F Timer" LED and 3 beeps every 3 seconds. The freeze
timer is factory set and no adjustment is required.
To reset either of these safeties, press the "ALARM RESET" button on the control board
with power on.
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 127±7°F (53±4°C), the control board reads a .8 kΩ
signal from the thermistor and shuts down the icemaker.
The control board signals with 1 beep every 3 seconds. To reset this safety, press the
"ALARM RESET" button on the control board with power on.
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 proceeds to the next cycle. If the oat switch
is in the down position (electrical circuit open), the control board returns to the 1-minute
ll cycle until water enters the tank and the oat switch closes. Once the oat switch
closes, the control board proceeds to the next cycle. The unit should not start without
adequate water in the tank. This serves as a low water safety to protect the pump motor
from mechanical seal failure.
For water-cooled model, if the water 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 unit are limited by the high
voltage and low voltage cut-outs.
Miswiring (especially on single phase 3 wire models) may cause excessive voltage
(147VAC±5% or more).
If high voltage (147VAC±5% or more) is present, the icemaker automatically stops and
the control board signals with 7 beeps every 3 seconds.
If low voltage (92VAC±5% or less) is present, the icmaker automatically stops and the
control board signals with 6 beeps every 3 seconds.
When the proper supply voltage is resumed, the icemaker automatically starts running
again.

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3. LED Lights and Audible Alarm Safeties
At startup, a 5-second delay occurs while the control board conducts an internal timer
check. A beep occurs when power is turned off. The red LED indicates proper control
voltage and remains on unless a control voltage problem occurs. The green LEDs 1
through 4 energize and sequence from startup as listed in the table below. Note that
the order of the LEDs from the outer edge of the control board is 1, 4, 3, 2. For more
information, see "II.B. Sequence of Operation."
Sequence Step LED Energized Time LEDs are On
Min. Max. Avg.
1-Minute Fill Cycle 4 WV 1 minute
Harvest Cycle 1, 4, 2 Comp, FMR,
WV, HGV
2 minutes 20 minutes 3 to 5 minutes
Freeze Cycle 1 Comp, FMR,
PM, LLV
5 minutes freeze timer
setting
30 to 35 minutes
Pump-Out Cycle 1, 4*, 3, 2 Comp, FMR,
WV*, PM,
HGV
10 seconds 20 seconds *pump-out timer
setting
The built in safeties shut down the unit and have alarms as listed below.
No. of Beeps
(every 3 sec.) Type of Alarm Notes
1High Evaporator Temp.
(temperature > 127°F)
(53°C)
Check for harvest problem (stuck HGV or
relay), hot water entering unit, stuck HM, or
shorted thermistor.
2Harvest Backup Timer
(harvest > 20 min. for
twocycles in a row)
Orange "H TIMER" LED on.
Check for open thermistor, HGV not opening,
TXV or LLV leaking by, WRV leaking by, low
charge, or inefficient Comp.
3Freeze Timer
(freeze > freeze timer
setting for two cycles in a
row)
Timer is factory set using
S4 dip switch 9 & 10
Yellow "F TIMER" LED on.
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 inefficient Comp.
To reset the above safeties, press the "ALARM RESET" button with the power supply on.
6Low Voltage
(92VAC±5% or less)
Red LED turns off if voltage protection
operates.
The control voltage safeties automatically reset
when voltage is corrected.
7High Voltage
(147VAC±5% or more)
Legend: Comp–compressor; 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

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4. 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 1-800-233-1940.
a) Default Dip Switch Settings
The dip switches are factory-adjusted to the following positions:
S4 Dip Switch
S4 Dip Switch No. 1 2 3 4 5 6 7 8 9 10
KM-2500SWH3 OFF OFF OFF OFF OFF OFF OFF OFF OFF ON
KM-2500SRH3 OFF OFF OFF OFF OFF OFF OFF OFF OFF ON
b) Harvest Timer (S4 dip switch 1 & 2)
The harvest timer starts when the thermistor warms to 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 1-800-233-1940 for recommendations. Keep in mind that setting the harvest
timer to a longer setting will decrease 24 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.4.c) Pump-Out Timer (S1 dip
switch 3 & 4)."
S4 Dip Switch Setting Time
(seconds)
No. 1 No. 2
OFF OFF 60
ON OFF 90
OFF ON 120
ON ON 180
Freeze Timer (9 & 10)
Pump-Out Frequency Control (5 & 6)
Pump-Out Timer (3 & 4)
Harvest Timer (1 & 2)
Bin Control Selector (7)
Factory Use (8)

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c) Pump-Out Timer (S4 dip switch 3 & 4)
When a pump-out is called for, the pump motor stops after the preceding freeze cycle.
The pump motor energizes 2 seconds later in the reverse direction, taking water from
the bottom of the tank and forcing pressure against the check valve seat allowing water
to go through the check valve and down the drain. At the same time, water ows through
the small oat switch tube to power ush the oat switch. 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, where water quality is bad and
the icemaker needs a longer pump-out time, the pump-out timer can be adjusted. The
pump-out timer control can be set to pump-out for 10 or 20 seconds.
S4 Dip Switch Setting Time (seconds) Inlet
Water
ValveNo. 3 No. 4 T1 T2
OFF OFF 10 150 closed
ON OFF 10 180 closed
OFF ON 10 120 open
ON ON 20 180 closed
T1: Time to drain the water tank
T2: Harvest timer at pump-out
d) Pump-Out Frequency Control (S4 dip switch 5 & 6)
The pump-out frequency control is factory set to drain the water tank every cycle, and
generally no adjustment is required. The pump-out frequency control can be set to have
a pump-out occur every cycle, or every 2,5, or 10 cycles.
The rst pump-out occurs after the 1st freeze cycle.
S4 Dip Switch Setting Frequency
No. 5 No. 6
OFF OFF every cycle
ON OFF every 2 cycles
OFF ON every 5 cycles
ON ON every 10 cycles