NO. 15FD-742
ISSUED: AUG. 10, 2007
SEP. 30, 2013
HOSHIZAKI
SELF-CONTAINED CRESCENT CUBER
MODEL KM-30A KM-35A KM-50A KM-75A
SERVICE MANUAL
CONTENTS |
PAGE |
I. SPECIFICATIONS-------------------------------------------------------------------------------------- |
1 |
1. DIMENSIONS/SPECIFICATIONS-------------------------------------------------------------- |
1 |
[a] KM-30A, KM-35A------------------------------------------------------------------------------- |
1 |
[b] KM-35A (Auxiliary code: V-1 or later, European model only)------------------------ |
2 |
[c] KM-50A-------------------------------------------------------------------------------------------- |
3 |
[d] KM-50A (Auxiliary code: V-1 or later, European model only)------------------------ |
4 |
[e] KM-75A-------------------------------------------------------------------------------------------- |
5 |
[f] KM-75A (Auxiliary code: V-1 or later, European model only)------------------------- |
6 |
II. GENERAL INFORMATION-------------------------------------------------------------------------- |
7 |
1. CONSTRUCTION----------------------------------------------------------------------------------- |
7 |
[a] KM-30A, KM-35A, KM-50A------------------------------------------------------------------- |
7 |
[b] KM-75A-------------------------------------------------------------------------------------------- |
8 |
[c] ICEMAKING COMPARTMENT-------------------------------------------------------------- |
9 |
2. CONTROL BOARD------------------------------------------------------------------------------- |
10 |
[a] SEQUENCE------------------------------------------------------------------------------------ |
11 |
[b] CONTROL FEATURES--------------------------------------------------------------------- |
14 |
[c] CONTROL BOARD LAYOUT-------------------------------------------------------------- |
16 |
[d] CONTROLS AND ADJUSTMENTS------------------------------------------------------ |
17 |
[e] ALARMS---------------------------------------------------------------------------------------- |
20 |
[f] CHECKING THE CONTROL BOARD---------------------------------------------------- |
21 |
3. SWITCHES----------------------------------------------------------------------------------------- |
22 |
III. TECHNICAL INFORMATION--------------------------------------------------------------------- |
23 |
1. WATER CIRCUITAND REFRIGERANT CIRCUIT--------------------------------------- |
23 |
[a] KM-30A, KM-35A, KM-50A----------------------------------------------------------------- |
23 |
[b] KM-75A------------------------------------------------------------------------------------------ |
24 |
2. WIRING DIAGRAM------------------------------------------------------------------------------- |
25 |
[a] KM-30A, KM-35A----------------------------------------------------------------------------- |
25 |
[b] KM-50A, KM-75A----------------------------------------------------------------------------- |
25 |
3. TIMING CHART------------------------------------------------------------------------------------ |
26 |
IV. SERVICE DIAGNOSIS---------------------------------------------------------------------------- |
27 |
1. NO ICE PRODUCTION-------------------------------------------------------------------------- |
27 |
2. EVAPORATOR IS FROZEN UP--------------------------------------------------------------- |
29 |
3. LOW ICE PRODUCTION----------------------------------------------------------------------- |
30 |
4. ABNORMAL ICE----------------------------------------------------------------------------------- |
30 |
5. OTHERS--------------------------------------------------------------------------------------------- |
31 |
V. REMOVALAND REPLACEMENT--------------------------------------------------------------- |
32 |
1. SERVICE FOR REFRIGERANT LINES----------------------------------------------------- |
32 |
[a] SERVICE INFORMATION------------------------------------------------------------------ |
32 |
[b] REFRIGERANT RECOVERY-------------------------------------------------------------- |
33 |
[c] EVACUATION AND RECHARGE--------------------------------------------------------- |
33 |
2. BRAZING-------------------------------------------------------------------------------------------- |
34 |
i
3. COMPRESSOR----------------------------------------------------------------------------------- |
35 |
4. DRIER------------------------------------------------------------------------------------------------ |
36 |
5. HOT GAS VALVE---------------------------------------------------------------------------------- |
37 |
6. EXPANSION VALVE - KM-75A ONLY-------------------------------------------------------- |
39 |
7. FAN MOTOR--------------------------------------------------------------------------------------- |
41 |
8. PUMP MOTOR------------------------------------------------------------------------------------ |
42 |
9. WATER VALVE------------------------------------------------------------------------------------ |
43 |
10. DRAIN VALVE------------------------------------------------------------------------------------- |
44 |
11. FLOAT SWITCH----------------------------------------------------------------------------------- |
45 |
[a] KM-30A, KM-35A, KM-50A----------------------------------------------------------------- |
45 |
[b] KM-75A------------------------------------------------------------------------------------------ |
46 |
12. BIN CONTROL SWITCH------------------------------------------------------------------------ |
47 |
13. THERMISTOR------------------------------------------------------------------------------------- |
50 |
14. CONTROL BOX----------------------------------------------------------------------------------- |
51 |
[a] POWER SWITCH----------------------------------------------------------------------------- |
52 |
[b] FUSE--------------------------------------------------------------------------------------------- |
52 |
[c] FUSE HOLDER------------------------------------------------------------------------------- |
52 |
[d] CONTROL BOARD--------------------------------------------------------------------------- |
52 |
[e] POWER RELAY------------------------------------------------------------------------------- |
52 |
[f] COMPRESSOR CAPACITOR - KM-50A, KM-75A ONLY--------------------------- |
53 |
[g] CONTROL BOARD TRANSFORMER--------------------------------------------------- |
53 |
15. WATER TANK-------------------------------------------------------------------------------------- |
53 |
16. CUBE GUIDE-------------------------------------------------------------------------------------- |
55 |
17. SEPARATOR--------------------------------------------------------------------------------------- |
56 |
18. SPRAY TUBE, WATER SUPPLY PIPE, SPRAY GUIDE-------------------------------- |
56 |
19. DOOR------------------------------------------------------------------------------------------------ |
57 |
VI. CLEANING AND MAINTENANCE INSTRUCTIONS-------------------------------------- |
58 |
1. CLEANING------------------------------------------------------------------------------------------ |
58 |
[a] CLEANING PROCEDURE----------------------------------------------------------------- |
58 |
[b] SANITIZING PROCEDURE---------------------------------------------------------------- |
60 |
2. MAINTENANCE----------------------------------------------------------------------------------- |
61 |
[a] EXTERIOR PANELS------------------------------------------------------------------------- |
61 |
[b] STORAGE BIN AND SCOOP-------------------------------------------------------------- |
61 |
[c] AIR FILTER------------------------------------------------------------------------------------- |
61 |
[d] CONDENSER--------------------------------------------------------------------------------- |
61 |
3. PREPARING THE ICEMAKER FOR LONG STORAGE-------------------------------- |
61 |
ii
I. SPECIFICATIONS
1. DIMENSIONS/SPECIFICATIONS
[a] KM-30A, KM-35A
1
[b] KM-35A (Auxiliary code: V-1 or later, European model only)
2
[c] KM-50A
3
[d] KM-50A (Auxiliary code: V-1 or later, European model only)
4
[e] KM-75A
5
[f] KM-75A (Auxiliary code: V-1 or later, European model only)
6
II. GENERAL INFORMATION
1. CONSTRUCTION
[a] KM-30A, KM-35A, KM-50A
Top Panel |
Separator |
Spray Tube |
Evaporator
Door |
Water Supply |
|
Front Panel |
Tube |
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Tank |
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Louver |
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Control Box |
|
Control Switch
Condenser
Hot Gas Valve |
Air Filter |
Fan Motor |
Front View
Thermistor
Water Valve 
Rear Panel
Pump Motor 
Pipe Cover
Power Supply
Cord
Drain Valve |
|
Drier |
Compressor |
Rear View
Rear Cover
|
Float Switch |
With Tank Removed |
Bin Control Switch |
7
[b] KM-75A
Top Panel |
Separator |
Spray Tube |
Evaporator
Door
Water Supply
Tube
Front Panel
Tank
Louver
Control Box
Control
Switch
Condenser
Hot Gas Valve |
Air Filter |
Fan Motor |
Compressor |
Front View
Thermistor
Water Valve
Rear Panel
Pump Motor
Pipe Cover
Power Supply
Cord
Drain Valve
Drier
Rear Cover |
Rear View |
Float Switch
With Tank Removed
Bin Control Switch
8
[c] ICEMAKING COMPARTMENT
Water Valve
Spray Tube |
Water Supply Pipe |
Evaporator |
Pump Motor
Separator
Cube Guide
Float Switch
Water Tank
9
2. CONTROL BOARD
*A HOSHIZAKI exclusive solid-state control is employed in KM-30A, KM-35A, KM-50A and KM-75A Crescent Cubers.
*All models are pretested and factory-adjusted.
CAUTION
1.Fragile, handle very carefully.
2.A control board contains integrated circuits, which are susceptible to failure due to static discharge. To get static free, it is especially important to touch the metal part of the unit when handling or replacing the board.
3.Do not touch the electronic devices on the board or the back of the board to prevent damage to the board. Handle the board by the edges only.
4.Do not change wiring and connections.
5.Do not repair the electronic devices or parts on the board in the field. Always replace the whole board assembly when it goes bad.
6.Do not short out the power supply to test for voltage. Also, never short out or modify the Terminals.
10
[a] SEQUENCE (see “III. 3. TIMING CHART” for details)
1st cycle
1.Unit energized and Control Switch to “ICE” position. Water supply cycle starts after 5 seconds.
2.After water supply cycle starts, Float Switch position is checked every minute. When it is in upper (closed) position, defrost cycle starts.
3.Thermistor reads 9°C. Defrost Timer starts counting.
To prevent slushing,
Pump Motor stops Stop (see “III. 3. TIMING CHART).
IMPORTANT
Water Valve opening is limited to 6 minutes after 2 .
4.At 30 seconds before the end of defrost cycle, Water Valve stops water supply and Pump Motor starts to run water on Evaporator surface.
6.At 5 minutes after thermistor temperature reaches 2°C in freeze cycle. Ready to complete freeze cycle when Float Switch circuit opens.
IMPORTANT
Board never accepts freeze completion signal within the first 5 minutes after thermistor temperature reaches 2°C.
5.Defrost Timer stops counting. Defrost cycle is completed and freeze cycle starts.
IMPORTANT
1.Board never accepts defrost completion signal within the first 2 minutes in defrost cycle.
2.Defrost cycle time is limited to 20 minutes even if Defrost Timer does not stop counting.
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2nd cycle and after
IMPORTANT
Freeze cycle time is limited to the time set by Freeze Backup Timer on Control Board (see “[d] CONTROLS AND ADJUSTMENTS”) even if Float Switch does not open.
1.Float Switch opens and signals to complete freeze cycle.
2.Thermistor reads 9°C. Defrost Timer starts counting.
To prevent slushing,
Pump Motor stops Stop (see “III. 3. TIMING CHART).
5.At 5 minutes after thermistor temperature reaches 2°C in freeze cycle. Ready to complete freeze cycle when Float Switch circuit opens.
IMPORTANT
Board never accepts freeze completion signal within the first 5 minutes after thermistor temperature reaches 2°C.
IMPORTANT opening
to 6 minutes.
before defrost cycle, stops water Pump Motor water on surface.
4.Defrost Timer stops counting. Defrost cycle is completed and freeze cycle starts.
IMPORTANT
1.Board never accepts defrost completion signal within the first 2 minutes in defrost cycle.
2.Defrost cycle time is limited to 20 minutes even if Defrost Timer does not stop counting.
12
2nd cycle and after (Drain Valve open)
IMPORTANT
Freeze cycle time is limited to the time set by Freeze Backup Timer on Control Board (see “[d] CONTROLS AND ADJUSTMENTS”) even if Float Switch does not open.
1.Float Switch opens and signals to complete freeze cycle.
Note:The Drain Valve is factory-adjusted to open every 10 cycles. This frequency is adjustable according to the water quality. See “[d] 4) Drain Counter” for further details.
2.Thermistor reads 9°C. Defrost Timer starts counting.
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DRAIN |
VALVE |
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6. After the freeze cycle |
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completes, Drain Valve |
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opens for 20 seconds |
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to drain out Water Tank. |
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20sec |
When Drain Valve closes, |
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Water Valve opens and |
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unit resumes normal |
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cycle. |
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To prevent slushing, |
Stop |
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Pump Motor stops |
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(see “III. 3. TIMING |
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CHART). |
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5.At 5 minutes after thermistor temperature reaches 2°C in freeze cycle. Ready to complete freeze cycle when Float Switch circuit opens.
IMPORTANT
Board never accepts freeze completion signal within the first 5 minutes after thermistor temperature reaches 2°C.
IMPORTANT opening
to 6 minutes.
before defrost cycle, stops water Pump Motor water on surface.
4.Defrost Timer stops counting. Defrost cycle is completed and freeze cycle starts.
IMPORTANT
1.Board never accepts defrost completion signal within the first 2 minutes in defrost cycle.
2.Defrost cycle time is limited to 20 minutes even if Defrost Timer does not stop counting.
13
[b] CONTROL FEATURES
1)Maximum Water Supply Period - 6 minutes
Inlet water valve opening, in the defrost cycle, is limited by the defrost timer. The water valve cannot remain open longer than the maximum period. The water valve can close in less than six minutes if the defrost cycle is completed.
2)Defrost Backup Timer
The defrost backup timer shuts down the icemaker if, for two cycles in a row, the defrost cycle takes more than 20 minutes to complete. The control board will signal this problem using 2 beeps every 3 seconds. The reset button on the control board must be pressed with power on to reset the safety.
3)Freeze Backup Timer
The freeze backup timer shuts down the icemaker if, for two cycles in a row, the freeze cycle takes longer than the time specified to complete. The control board will signal this problem using 3 beeps every 3 seconds. The time is factory set using dip switches 9 &10. The safety will be reset when the control switch is turned off and back on.
4)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 rises above 53°C ± 4°C, the thermistor operates the safety. This shuts down the circuit and the icemaker automatically stops.
The control board will signal this problem using 1 beep every 3 seconds. The reset button on the control board must be pressed with power on to reset the safety.
5)Low Water Safety
The control board checks the position of the float switch at the end of the initial one minute water fill cycle and at the end of each defrost cycle.
If the float switch is in the up position (electrical circuit closed), the control board changes to the next cycle. If the float switch is in the down position (electrical circuit open), the control board changes to additional one minute water fill cycles until water enters the sump and the float switch closes. When the float switch closes, the control board changes to the next cycle. The unit will not start without adequate water in the sump. This serves as a low water safety to protect the water pump.
6)High Voltage and Low Voltage Cut-outs
The maximum and minimum allowable supply voltages of this icemaker are limited by the high voltage and low voltage cut-outs.
14
If miswiring (especially on single phase 3 wire models) causes excessive voltage
(294Vac ±5% or more) on the control board, the high voltage cut-out shuts down the circuit in 3 seconds and the icemaker automatically stops. The control board will signal this problem using 7 beeps every 3 seconds.
The icemaker also automatically stops in cases of insufficient voltage (184Vac ±5% or less). The control board will signal this problem using 6 beeps every 3 seconds.
When the proper supply voltage is resumed, the icemaker automatically starts running again.
7)LED Lights
The control board includes LED indicator lights and an output test feature. The
"POWER OK" LED indicates control voltage and will remain on unless a control voltage problem occurs. The “POWER OK” LED flashes continuously when the bin is full. LEDs 4 through 8 energize and sequence from initial startup as listed in the table below.
Sequence Step |
LED |
Energized Components |
First Water Fill Cycle |
8 |
Water valve |
Defrost Cycle |
5, 6, 8 |
Water valve, hot gas valve, compressor |
Last 30 seconds of defrost, water valve de-energizes and pump motor energizes |
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(LEDs 5, 6, and 7 are on) |
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|
Freeze Cycle |
5, 7 |
Compressor, pump motor, fan motor |
Drain |
5, 6, 4 |
Compressor, hot gas valve, drain valve |
15
[c] CONTROL BOARD LAYOUT
Connector K3
Magnetic Contactor
Connector K4
Open
POWER OK LED (Lights when power is supplied to the board. Flashes when bin control is activated.)
Connector K5 |
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Pins |
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#1 Fan Motor |
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#2 Hot Gas Valve |
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#3 Pump Motor |
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#4 Water Valve |
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#5 Open |
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#6 Drain Valve |
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Connector K6 |
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Open |
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Connector K1 |
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Pins |
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#1, 3 Float Switch |
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#2 Open |
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#4, 5 Bin Control |
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#6, 7 Thermistor |
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#8, 9 Open |
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Connector K2 |
Alarm Buzzer |
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Open |
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"H" Control Board
Connector K7 |
Relay LEDs (5) |
(indicate which relays |
|
Transformer |
are energized as |
|
listed below) |
|
LED 5 (X1 Relay) |
|
Compressor |
|
LED 6 (X2 Relay) |
|
Hot Gas Valve |
|
Fan Motor (Fan Motor |
|
off when LED on) |
|
LED 8 (X4 Relay) |
|
Water Valve |
LED 4 (X6 Relay)
Drain Valve
LED 7 (X3 Relay)
Pump Motor
Connector K8
Open
Output Test Button (used to test relays on board)
Dip Switch |
Alarm Reset Button |
Control Board
Auxiliary Code |
V0 or Earlier |
V1 or Later |
Factory Part Number |
P00013-03 |
P01771-01 |
Service Part Number |
P00013-02 |
P01771-02 |
Type |
HKM2006V003 |
|
16
[d] CONTROLS AND ADJUSTMENTS
1) Dip Switch
The Dip Switches on the Control Board are factory-adjusted to the following positions:
Dip Switch No. |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
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KM-30A |
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KM-35A |
OFF |
OFF |
ON |
ON |
ON |
ON |
OFF |
ON |
ON |
ON |
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KM-50A |
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KM-75A |
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CAUTION
Do not change the settings of the Dip Switch Nos. 3, 4, 7, 8, 9 and 10, or the unit will not operate properly.
If the S2 Dip Switch is mounted on the Control Board, all should be left in the “OFF” position.
Switch Nos. 1 and 2:
Used for adjustment of the Defrost Timer.
The Defrost Timer starts counting when the Thermistor reads a certain temperature at the Evaporator outlet.
Switch Nos. 3 and 4:
Used for adjustment of the Drain Timer and the minimum defrost time.
Once every ten freeze cycles, the Drain Valve opens to drain the Water Tank for the time determined by the Drain Timer. These switches also determine the time to delay completion of a defrost cycle, i.e. the minimum defrost time.
Do not change this setting, or the unit will not operate properly or produce high quality ice.
Switch Nos. 5 and 6:
Used for adjustment of the Drain Counter.
The Drain Valve opens to drain the Water Tank at the frequency determined by the
Drain Counter. Once every ten freeze cycles, the Drain Valve drains the Water Tank to clean inside the tank and prevent cloudy ice production by concentrated icemaking water. This function ensures proper operation even in hard water conditions. The frequency of this drain cycle can be changed to every cycle, every two cycles, or every five cycles.
Switch Nos. 7 and 8
Used for adjustment of the Water Saver.
The Water Saver closes the Water Valve to save water when the Pump Motor starts to supply water to the Evaporator 30 seconds before the end of defrost cycle. Do not change this setting.
17
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