Hoshizaki KM-280MWH Service manual
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NO. 73117
ISSUED: AUG. 15, 2004
REVISED:
HOSHIZAKI
MODULAR CRESCENT CUBER
MODEL
KM-280MAH
KM-280MWH
SERVICE MANUAL
IMPORTANT
Only qualified service technicians should attempt to service or maintain this icemaker.
No service or maintenance should be undertaken until the technician has thoroughly read this Service Manual.
HOSHIZAKI provides this manual primarily to assist qualified 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 or write 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: 1-800-233-1940 Technical Service
(770) 487-2331
Fax: (770) 487-3360
NOTE: To expedite assistance, all correspondence/communication MUST include the following information:
• Model Number
• Serial Number
• Complete and detailed explanation of the problem
2
• Please review this manual. It should be read carefully before the icemaker is serviced or maintenance operations performed. Only qualified service technicians should service and maintain the icemaker. This manual should be made available to the technician prior to service or maintenance.
CONTENTS
PAGE
I. SPECIFICATIONS ...................................................................................................... 5
1. KM-280MAH (Air-cooled) ..................................................................................... 5
2a. KM-280MWH (Water-cooled) Serial #L00001E - M10134C ............................... 6
2b. KM-280MWH (Water-cooled) Serial #M20315D ................................................ 7
II. GENERAL INFORMATION ........................................................................................ 8
1. CONSTRUCTION................................................................................................. 8
[a] KM-280MAH (Air-cooled) ............................................................................... 8
[b] KM-280MWH (Water-cooled) ......................................................................... 9
2. CONTROLLER BOARD ..................................................................................... 10
[a] SOLID-STATE CONTROL ........................................................................... 10
[b] CONTROLLER BOARD ............................................................................... 10
[c] SEQUENCE ................................................................................................ 14
[d] CONTROLS AND ADJUSTMENTS ............................................................. 17
[e] CHECKING CONTROLLER BOARD ........................................................... 21
3. MECHANICAL BIN CONTROL........................................................................... 22
[a] PROXIMITY SWITCH ................................................................................... 22
[b] EXPLANATION OF OPERATION................................................................ 22
[c] TROUBLESHOOTING ................................................................................. 23
III. TECHNICAL INFORMATION .................................................................................. 24
1. WATER CIRCUIT AND REFRIGERANT CIRCUIT .............................................. 24
[a] KM-280MAH ................................................................................................ 24
[b] KM-280MWH ............................................................................................... 25
2. WIRING DIAGRAMS .......................................................................................... 26
[a] KM-280MAH and KM-280MWH ................................................................... 26
3. TIMING CHART .................................................................................................. 28
4. PERFORMANCE DATA .................................................................................... 30
[a] KM-280MAH ................................................................................................ 30
[b] KM-280MWH Serial #L00001E - M10134C ................................................. 31
[c] KM-280MWH Serial #M20315D .................................................................. 32
3
IV. SERVICE DIAGNOSIS........................................................................................... 33
1. NO ICE PRODUCTION ......................................................................................... 33
2. EVAPORATOR IS FROZEN UP .......................................................................... 36
3. LOW ICE PRODUCTION ...................................................................................... 37
4. ABNORMAL ICE .................................................................................................. 37
5. OTHERS .............................................................................................................. 37
V. REMOVAL AND REPLACEMENT OF COMPONENTS ............................................ 38
1. SERVICE FOR REFRIGERANT LINES .............................................................. 38
[a] REFRIGERANT RECOVERY ........................................................................ 38
[b] EVACUATION AND RECHARGE [R-404A] ................................................... 38
2. BRAZING ............................................................................................................. 39
3. REMOVAL AND REPLACEMENT OF COMPRESSOR ....................................... 40
4. REMOVAL AND REPLACEMENT OF DRIER ..................................................... 42
5. REMOVAL AND REPLACEMENT OF EXPANSION VALVE ............................... 42
6. REMOVAL AND REPLACEMENT OF HOT GAS VALVE AND ...............................
LINE VALVE ........................................................................................................ 43
7. REMOVAL AND REPLACEMENT OF EVAPORATOR ........................................ 45
8. REMOVAL AND REPLACEMENT OF WATER-REGULATING VALVE ..................
- WATER COOLED MODEL ONLY ..................................................................... 46
9. ADJUSTMENT OF WATER-REGULATING VALVE ................................................
- WATER COOLED MODEL ONLY ..................................................................... 47
10. REMOVAL AND REPLACEMENT OF THERMISTOR ........................................ 48
11. REMOVAL AND REPLACEMENT OF FAN MOTOR ........................................... 49
12. REMOVAL AND REPLACEMENT OF WATER VALVE ........................................ 50
13. REMOVAL AND REPLACEMENT OF PUMP MOTOR ......................................... 50
14. REMOVAL AND REPLACEMENT OF SPRAY TUBES ........................................ 51
VI. CLEANING AND MAINTENANCE INSTRUCTIONS ............................................... 52
1. PREPARING THE ICEMAKER FOR LONG STORAGE...................................... 52
2. CLEANING ........................................................................................................... 54
[a] CLEANING PROCEDURE ............................................................................. 55
[b] SANITIZING PROCEDURE ........................................................................... 57
3. MAINTENANCE.................................................................................................... 58
4
I. SPECIFICATIONS
1. KM-280MAH (Air-cooled)
Note: We reserve the right to make changes in specifications and design without prior notice.
5
2a. KM-280MWH (Water-cooled)
Serial #L00001E- M10134C
Note: We reserve the right to make changes in specifications and design without prior notice.
6
2b. KM-280MWH (Water-cooled)
Serial #M20315D -
Note: We reserve the right to make changes in specifications and design without prior notice.
7
II. GENERAL INFORMATION
1. CONSTRUCTION
[a] KM-280MAH (Air-cooled)
Spray Tubes
Control Switch
Bin Control Thermostat
(except models with
Mechanical Bin Control)
Expansion Valve
Compressor
Float Switch
Water Pump
Mechanical
Bin Control
(except models with Thermostat)
8
Water Supply Inlet
Condenser
Hot Gas Valve
Fan Motor
Condenser
Drier
Control Box
[b] KM-280MWH (Water-cooled)
Spray Tubes
Control Switch
Bin Control Thermostat
(except models with
Mechanical Bin Control)
Expansion Valve
Compressor
Float Switch
Water Pump
Mechanical
Bin Control
(except models with Thermostat)
9
Water Supply Inlet
Water Regulator
Hot Gas Valve
Drier
Control Box
2. CONTROLLER BOARD
[a] SOLID-STATE CONTROL
1) A HOSHIZAKI exclusive solid-state control is employed in Modular Crescent Cubers.
2) A Printed Circuit Board (hereafter called “Controller Board”) includes a stable and high quality control system.
3) All models are pretested and factory-adjusted.
[b] CONTROLLER BOARD
CAUTION
1. Fragile, handle very carefully.
2. A controller 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 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.
4. Do not change wiring and connections. Do not misconnect K3, K4 and K5, because the same connector is used for the Thermistor (white), Float Switch
(black), and Mechanical Bin Control (red).
(For machines with thermostat, there is no connection on K4.)
5. Always replace the whole board assembly when it goes bad.
6. Do not short out power supply to test for voltage.
PART NUMBER TYPE
2A1410-01 HOS-001A (Control Products)
Features of Control Products “E” Controller Board
1) Maximum Water Supply Period - 6 minutes
Water Solenoid Valve opening, in the Defrost (Harvest) 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.
10
2) Defrost Timer
The defrost cycle starts when the Float Switch opens and completes the freeze cycle. But the Defrost Timer does not start counting until the Thermistor senses 48°F at the Evaporator outlet. The period from the end of the freeze cycle up to the point of the Thermistor's sensing varies depending on the ambient and water temperatures.
3) High Temperature Safety - 127 ± 7°F
The temperature of the suction line in the refrigerant circuit is limited by the High
Temperature Safety.
During the defrost cycle the Evaporator temperature rises. The Thermistor senses
48°F and starts the Defrost Timer. After the Defrost Timer counts down to zero, the normal freeze cycle begins. If the Evaporator temperature continues to rise, the Thermistor will sense the rise in temperature and at 127 ± 7°F the Thermistor operates the High Temperature Safety.
This High Temperature Safety shuts down the circuit and the icemaker automatically stops.
This High Temperature Safety protects the unit from excessive temperature. The Control
Board will Beep every 3 seconds. The white Reset Button on the Control Board must be pressed with power on to reset the Safety.
4) Low Water Safety
If the Pump Motor is operated without water, the mechanical seal can fail. To prevent this type of failure, the Controller 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 Controller Board changes to the ice making cycle. If the Float Switch is in the down position (electrical circuit open), the Controller Board changes to a one minute water fill cycle before starting the ice making cycle. This method allows for a Low Water Safety shut down to protect the
Water Pump from mechanical seal failure.
For water-cooled model, if the water is shut off, the unit is protected by the High Pressure
Switch.
5) High Voltage Cutout
The maximum allowable supply voltage of this icemaker is limited by the High Voltage Cutout.
If miswiring (especially on single phase 3 wire models) causes excessive voltage on the
Controller Board, the High Voltage Cutout shuts down the circuit in 3 seconds and the icemaker automatically stops. When the proper supply voltage is resumed, the icemaker automatically starts running again. The Control Board will signal this problem using 7 Beeps every 3 seconds.
6) LED Lights and Audible Alarm Safeties
The red LED indicates proper control voltage and will remain on unless a control voltage problem occurs. At startup a 5 second delay occurs while the board conducts an internal timer check. A short beep occurs when the power switch is turned ON or OFF.
11
The green LED’s 1-4 represent the corresponding relays and energize and sequence 5 seconds from initial start-up as follows:
Max.
Sequence Step LED’s on Length: Min.
1 Minute Fill Cycle
LED4
Harvest Cycle
LED1, 4, & 2 2 min.
Freeze Cycle
LED1
Reverse Pump Out
LED1, 3, & 2
5 min.
10 sec.
20 min.
60 min.
20 sec.
Avg.
60 sec.
3-5 min.
30-35 min.
Factory set.
{LED 1 – Comp; LED 2 - HGV/CFM; LED 3 – PM; LED 4 - WV}
The built in safeties shut down the unit and have alarms as follows:
1 beep every 3 sec. = High Evaporator Temperature >127 ° F.
Check for defrost problem (stuck HGV or relay), hot water entering unit, stuck headmaster, or shorted thermistor.
2 beeps every 3 sec. = Defrost Back Up Timer. Defrost >20 minutes.
Orange LED marked 20 MIN energizes.
Check for open thermistor, HGV not opening, TXV leaking by, low charge, or inefficient compressor.
3 beeps every 3 sec. = Freeze Back Up Timer. Freeze > 60 minutes.
Yellow LED marked 60 MIN energizes.
Check for F/S stuck closed (up), WV leaking by, HGV leaking by, TXV not feeding properly, low charge, or inefficient compressor.
Machines with mechanical bin control
ONLY
4 beeps every 3 sec. = Short Circuit between the K4 connection on the control board and the bin control relay. Check connections and replace wire harness if necessary.
5 beeps every 3 sec. = Open Circuit between the K4 connection on the control board and the bin control relay. Check connections and replace wire harness if necessary.
To manually reset the above safeties, depress white alarm reset button with the power supply ON.
6 beeps every 3 sec. = Low Voltage. Voltage is 92 Vac or less.
7 beeps every 3 sec. = High Voltage. Control voltage > 147 Vac ±5%.
The red LED will de-energize if voltage protection operates.
The voltage safety automatically resets when voltage is corrected.
The Output Test switch “S3” provides a relay sequence test. With power OFF, place S3
ON and switch power to ICE. The correct lighting sequence should be none, 2, 3, 4, 1, & 4, normal sequence every 5 seconds. S3 should remain in the “OFF” position for normal operation.
12
The application switch located between relay X3 & X4 must be set to match the original board application. Place this switch in the ALP position if there is no white wire supplied to the K1 connector. If there is a white wire, place the switch in the C position. If this switch is placed in the wrong position, either the compressor contactor will remain energized with the control switch OFF, or the unit will not start.
The dip switches should be adjusted per the adjustment chart published in the Tech
Specs book. Number 8 must remain in the OFF position.
(Control Products HOS-001A Board)
13
[c] SEQUENCE
1st Cycle
1. Unit energized and Control Switch to “ICE”
position. Water supply cycle starts.
2. After 1 minute,
Defrost cycle starts.
3. Thermistor reads 48° F.
Defrost Timer starts counting.
IMPORTANT
Water Valve opening is limited to 6 minutes.
&
5. After the first 5 minutes 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 in freeze cycle.
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.
14
2nd Cycle and after with pump drain
IMPORTANT
Freeze cycle time is limited to 60 minutes even if Float Switch does not open.
1. Float Switch opens and signals to complete
freeze cycle.
Drain timer starts counting.
2. Drain timer stops counting.
Pump drain is completed
&
3. Thermistor reads 48° F.
Defrost Timer starts
counting.
IMPORTANT
Water Valve opening is limited to 6 minutes.
5. After the first 5 minutes 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 in freeze cycle.
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.
15
2nd Cycle and after with no pump drain
IMPORTANT
Freeze cycle time is limited to 60 minutes even if Float Switch does not open.
1. Float Switch opens and signals to complete
freeze cycle.
2. Thermistor reads 48° F.
Defrost Timer starts counting.
IMPORTANT
Water Valve opening is limited to 6 minutes.
&
4. After the first 5 minutes 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 in freeze cycle.
3. 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.
16
[d] CONTROLS AND ADJUSTMENTS
The Dip Switch is factory-adjusted to the following positions:
FOR MODELS WITH MECHANICAL BIN CONTROL:
DIP SWITCH NO.
1
KM-280MAH
2 3 4 5 6 7 8 9 10
ON OFF OFF ON ON ON ON OFF OFF OFF
KM-280MWH
OFF OFF OFF ON ON ON ON OFF OFF ON
FOR MODELS WITH THERMOSTAT :
DIP SWITCH NO.
1
KM-280MAH
2 3 4 5 6 7 8 9 10
ON OFF OFF ON ON ON OFF OFF OFF OFF
KM-280MWH
OFF OFF OFF ON ON ON OFF OFF OFF ON
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.
When a freeze cycle is completed, the Pump Motor stops, and the icemaker
resumes operation in 2 seconds. Then the Pump Motor drains the Water Tank
for the time determined by the Drain Timer. The Drain Timer also determines the
time to restrain completion of a defrost cycle, i.e. the minimum defrost time.
Switch Nos. 5 and 6:
Used for adjustment of the Drain Counter.
The Pump Motor drains the Water Tank at the frequency determined by the Drain
Counter.
Switch No. 7:
Used only on models with mechanical bin control. Dip Switch should be set “ON”.
(Models with bin thermostat, Switch No. 7 should be set in the “OFF” position.)
Switch No. 8:
Used only for checking the Controller Board. Usually set in OFF position.
17
Switch Nos. 9 and 10:
Used for adjustment of Freeze Timer.
The Freeze Timer determines maximum freeze cycle time. Upon termination of
Freeze Timer, machine initiates the harvest cycle. After 2 consecutive timer terminations, machine will shut down, possibly indicating a problem.
1) Defrost Control
A thermistor (Semiconductor) is used for a defrost control sensor. The resistance varies depending on the Suction Line temperatures. The Thermistor detects the temperature of the Evaporator outlet to start the Defrost Timer. No adjustment is required. If necessary, check for resistance between Thermistor leads, and visually check the Thermistor mounting, located on the Suction Line next to the Evaporator outlet.
Temperature (°F) Resistance (k
Ω
)
0 14.401
10 10.613
32
50
6.000
3.871
70
90
2.474
1.633
Check a thermistor for resistance by using the following procedures.
(i) Disconnect the connector K3 on the board.
(ii) Remove the Thermistor. See “V. 10. REMOVAL AND REPLACEMENT OF
THERMISTOR.”
(iii) Immerse the Thermistor sensor portion in a glass containing ice and water for 2 or 3 minutes.
(iv) Check for a resistance between Thermistor leads.
Normal reading is within 3.5 to 7 k
Ω
. Replace the Thermistor if it exceeds the normal reading.
18
2) Defrost Timer
No adjustment is required under normal use, as the Defrost Timer is adjusted to the suitable position. However, if necessary when all the ice formed on the Evaporator does not fall into the bin in the harvest cycle, adjust the Defrost Timer to longer setting by adjusting the Dip
Switch (No. 1 & 2) on the Controller Board.
TIME SETTING
Dip Switch
No. 1
Dip Switch
No. 2
OFF
ON
OFF
ON
OFF
OFF
ON
ON
60 seconds
90 seconds
120 seconds
180 seconds
3) Drain Timer
The Drain Timer is factory-adjusted, and no adjustment is required.
TIME SETTING
Dip Switch
No. 3
Dip Switch
No. 4
OFF
ON
OFF
ON
OFF
OFF
ON
ON
T1: Time to drain the Water Tank
T2: Time to restrain defrost completion
T1
10 seconds
10 seconds
10 seconds
20 seconds
T2
150 seconds
180 seconds
120 seconds
180 seconds
4) Drain Counter
CAUTION
Do not adjust the Drain Counter, or the Evaporator may freeze up.
The Drain Counter is factory-adjusted to drain the Water Tank every 10 cycles, and no adjustment is required. However, where water quality is bad and the icemaker needs a pump drain more often, the Drain Counter can be adjusted as shown in the table below:
19
SETTING
Dip Switch Dip Switch
No. 5 No. 6
OFF
ON
OFF
ON
OFF
OFF
ON
ON
FREQUENCY every cycle every 2 cycles every 5 cycles every 10 cycles
5) Freeze Timer
CAUTION
Adjust to proper specification, or the unit may not operate correctly.
Two new dip switches numbered 9 and 10 have been added to the improved “E” board to better prevent possible freeze ups. These settings come factory set to the default setting of 60 min. (OFF, OFF). Check the adjustment chart published in the Tech
Specs for proper settings. If the old board does not have these two dip switches, (only
8 instead of 10), leave setting as OFF, OFF.
SETTING
Dip Switch Dip Switch
No. 9 No. 10
OFF
ON
OFF
ON
OFF
OFF
ON
ON
TIME
60 min.
70 min.
50 min.
60 min.
6) Bin Control
MODELS WITH THERMOSTAT
CAUTION
When the ambient temperature is below 45°F, the Bin Control Thermostat operates to stop the icemaker even if the Ice Storage Bin is empty. When the Thermostat is set in the prohibited range, the icemaker operates continuously even if the Ice Storage Bin is filled with ice. Setting in the prohibited range might cause severe damage to the icemaker resulting in failure.
No adjustment is required under normal use, as the Bin Control is factory-adjusted. Adjust it, if necessary, so that the icemaker stops automatically within 10 seconds after ice contacts the Bin Control Thermostat Bulb.
20
MODELS WITH MECHANICAL BIN CONTROL
CAUTION
Dip Switch No. 7 must be set to the ON position. If No. 7 is set to the OFF position, the machine will run continuously, causing a freeze-up condition.
No adjustment is required. The Bin Control is factory-adjusted.
[e] CHECKING THE CONTROLLER BOARD
1) Visually check the sequence with the icemaker operating.
2) Visually check the Controller Board by using the following procedures.
(i) Adjust the Defrost Timer to minimum position.
Disconnect the Thermistor from the Controller Board.
Connect a 1.5 k
Ω
- 3.5 k
Ω
resistor to the Connector K3 (pins #1 and #2), and energize the unit.
After the 1 minute ± 5 second water supply cycle and the 2 minute ± 10 second defrost cycle, the unit should start the freeze cycle.
(ii) After the above step (i), disconnect the Float Switch leads from the Controller Board within the first 5 minutes of the freeze cycle.
The unit should go into the defrost cycle after the first 5 minutes ± 20 seconds of the freeze cycle.
(iii) Reconnect the Float Switch Connector to the Controller Board. After the first 5 minutes of the freeze cycle, disconnect the Float Switch leads from the Controller
Board.
At this point, the unit should start the defrost cycle.
(iv) After Step (iii), de-energize the unit and confirm that the Defrost Timer is in the minimum position. Disconnect the resistor from the Controller Board, and energize the unit.
After the 1 minute water supply cycle, the defrost cycle starts.
Reconnect a 1.5 k
Ω
- 3.5 k
Ω
resistor to the Connector K3 (pins #1 and #2) after the first 2 minutes of the defrost cycle.
The unit should start the freeze cycle after 1 minute ± 5 seconds from the resistor
connection.
21
3) Check the Controller Board by using test program of the Controller Board.
The Output Test Switch “S3” provides a relay sequence test. With power OFF, place S3 on and switch power to ICE. The correct lighting sequence should be none, 2, 3, 4, 1, and 4, normal sequence every 5 seconds. S3 should remain in the “OFF” position for normal operation.
3. MECHANICAL BIN CONTROL
(THESE INSTRUCTIONS NOT APPLICABLE TO MODELS WITH THERMOSTAT)
[a] PROXIMITY SWITCH
1) This machine uses a lever-actuated proximity switch (hereafter called “mechanical bin control”) to control the ice level in the storage bin.
[b] EXPLANATION OF OPERATION
1) The startup and shutdown of the ice machine is controlled via the controller board. Dip
Switch number 7 must be in the ON position for the controller board to receive input from the bin control.
(i) The controller board receives a resistance value input via the red K4 connector
from the bin control. A resistor wire harness is connected from the bin control to
the controller board.
(ii) When the bin control is activated in the bin full position (pushed to the right), a
15.8 K
Ω
signal will be sent to the control board to shut down the unit.
(iii) When the bin control is in the normal position (bin is not full), a 7.9 K
Ω
reading is
sent to the control board to continue operation.
2) During operation, the controller board will only shut down the machine if a 15.8 K
Ω
signal is received from the bin control during the first 5 minutes of the freeze cycle.
(i) If ice pushes the lever to the right after the first five minutes of the freeze cycle,
the controller board will allow the machine to complete the freeze cycle and the
following harvest cycle before shutting down the machine. This will prevent
incomplete batches of ice from forming on the evaporator.
22
[c] TROUBLESHOOTING (MECHANICAL BIN CONTROL ONLY)
1) Machine will not start
(i) Move dip switch No. 7 to the “OFF” position. If the machine starts up within a few
seconds, the bin control is the likely problem. If the machine does not start up,
refer to Section “IV. Service Diagnosis” to verify that non-bin control related issues
are resolved.
(ii) Check to make sure shipping tape has been removed and the wires are connected
properly.
(iii) Check to make sure no obstruction prevents the lever from moving to the bin empty
position.
2) Machine will not shut off
(i) Refer to Section “IV. Service Diagnosis” to verify that non-bin control related issues
are resolved.
(ii) Dip switch No. 7 should be in the on position. If the switch is in the off position, the
controller board will not receive input from the bin control.
(iii) Move the lever to the far right.
a. If the machine does not shut off, check the resistance values of the resistor wire harness. You should read approximately 15.8 K
Ω
between the black terminal and the red terminal that connect to the K4 connector on the controller board, when the lever is in the bin full position (far right). If this reads approximately 7.9 K
Ω
, the resistors may be miswired. Switch the black and white wires in the terminal housing or order a replacement wire harness.
b. Check the stainless steel bracket that the bin control is mounted to.
c. If the preceding items do not resolve the problem, replace the Bin Control
Assembly.
23
III. TECHNICAL INFORMATION
1. WATER CIRCUIT AND REFRIGERANT CIRCUIT
[a] KM-280MAH
24
[b] KM-280MWH
25
2. WIRING DIAGRAMS
[a] KM-280MAH (with auxiliary codes L-0, M-0, and M-1)
and KM-280MWH (with auxiliary codes L-0, M-0, and M-1)
Note: Pressure Switch
MAH
Cut-out 412 ±
21
0
Cut-in
PSIG
327 ± 21 PSIG
26
MWH
MWH
Cut-out 384 ±
21
0
PSIG
Cut-in 284 ± 21 PSIG
KM-280MAH (with auxiliary codes M-2 and after) and KM-280MWH (with auxiliary codes M-2 and after)
27
3. TIMING CHART
28
29
4. PERFORMANCE DATA
[a] KM-280MAH
Note: Pressure data is recorded at 5 minutes into freeze cycle. The data not in bold should be used for
reference only.
We reserve the right to make changes in specifications and design without prior notice.
30
[b] KM-280MWH
Serial #L00001E- M10134C
Note: Pressure data is recorded at 5 minutes into freeze cycle. The data not in bold should be used for
reference only.
We reserve the right to make changes in specifications and design without prior notice.
31
[c] KM-280MWH
Serial #M20315D -
Note: Pressure data is recorded at 5 minutes into freeze cycle. The data not with * should be used for
reference only.
We reserve the right to make changes in specifications and design without prior notice.
32
IV. SERVICE DIAGNOSIS
1. NO ICE PRODUCTION
PROBLEM POSSIBLE CAUSE REMEDY
[1] The icemaker
will not start a) Power Supply d) Bin Control
Thermostat
For mechanical bin control see “II. 3. [c]”
e) High Pressure
Control f) Transformer g) Wiring to
Controller Board h) Thermistor i) Hot Gas Solenoid
Valve j) Water Supply Line
1. “OFF” position.
2. Loose connections.
3. Bad contacts.
4. Voltage too high.
b) Fuse (Inside Fused 1. Blown out.
Disconnect, if any) c) Control Switch 1. “OFF” position.
2. Bad contacts.
1. Move to “ON” position
2. Tighten
3. Check for continuity and
replace.
4. Check and get
recommended voltage.
1. Check for short circuit
and replace
1. Move to “ICE” position.
2. Check for continuity and
replace.
1. Remove ice.
1. Tripped with bin filled
with ice.
2. Ambient temperature
too cool.
3. Set too warm.
4. Bulb out of position.
5. Bad contacts or leaks
bulb.
1. Bad contacts.
2. Increase ambient
temperature.
3. See “II.2.[d]
CONTROLS AND
ADJUSTMENTS, 5) Bin
Control.”
4. Place in position.
5. Check for continuity and
replace.
1. Check for continuity and
replace.
1. Replace.
1. Thermal fuse blown out
or coil winding opened.
1. Loose connections or
open.
1. Leads short-circuit or
open and High
Temperature Safety
operates.
1. Check for continuity and
replace.
1. See “II.2.[d] CONTROLS
AND ADJUSTMENTS, 1)
Defrost Control.”
1. Continues to open in
freeze cycle and High
Temperature Safety
operates.
1. Check for power off in
freeze cycle and replace.
1. Water supply off and
water supply cycle does
1. Check and get
recommended pressure.
not finish.
2. Condenser water pressure 2. Check and get k) Water Solenoid
too low or off and Pressure recommended pressure.
Control opens and closes
frequently to finally operate
High Temperature Safety.
1. Mesh filter or orifice gets
clogged and water supply
1. Clean.
cycle does not finish.
2. Coil winding opened.
3. Wiring to Water Valve.
2. Replace.
3. Check for loose connection
or open, and replace.
33
PROBLEM POSSIBLE CAUSE REMEDY l) Controller Board 1. Defective 1. See “II.2[e] CHECKING m) Interlock Switch
(Cleaning Valve)
[2] Water
continues to
be supplied,
and the icea) Float switch
maker will not b) Controller Board
start.
[3] Compressor a) Wash Switch
1. “OFF” position.
2. Bad contacts.
1. Connector disconnected.
2. Leads opened or defective 2. Check and replace.
switch.
3. Float does not move freely.
3. Clean or replace.
1. Defective.
CONTROLLER BOARD.”
1. Move to “ON” position.
2. Check for continuity and
replace.
1. Place in position.
1. Replace.
b) High Pressure
Controller
1. “WASH” position.
2. Bad contacts.
1. Dirty Air Filter or
Condenser.
1. Move to “ICE” position.
2. Check and replace.
1. Clean.
2. Ambient or condenser
water temp. too warm.
too low or off. [Water-
cooled model only].
2. Reduce ambient temp.
3. Refrigerant overcharged.
3. Recharge.
4. Condenser water pressure 4. Check and get
recommended pressure.
5. Fan not operating. [Except 5. See chart 1 - [6].
water-cooled model].
6. Refrigerant line or
components plugged.
6. Clean and replace Drier.
c) Water Regulator 1. Set too high.
d) Overload Protector 1. Bad contacts.
1. Adjust lower.
1. Check for continuity and
2. Voltage too low.
replace.
2. Increase voltage.
3. Refrigerant overcharged or 3. Recharge.
[4] Water
continues to
be supplied in
freeze cycle.
undercharged.
4. Line Valve continues to
close in freeze cycle and
Overload Protector e) Starter
operates.
1. Bad contacts.
2. Coil winding opened.
1. Defective.
f) Start Capacitor or
Run Capacitor g) Magnetic Contactor 1. Bad contacts.
h) Compressor i) Controller board a) Water Solenoid
Valve b) Controller Board
4. Check Line Valve's
operation in freeze cycle
and replace.
1. Check and replace.
2. Replace.
1. Replace.
2. Coil winding opened.
1. Wiring to Compressor.
1. Check for continuity and
replace.
2. Replace.
1. Check for loose
2. Defective.
3. Protector tripped.
1. Defective.
connection or open, and
replace.
2. Replace.
3. Reduce temperature.
1. See “II.2. [e] CHECKING
CONTROLLER BOARD.”
1. Diaphragm does not close.
1. Check for water leaks
with icemaker off.
1. Defective.
1. See “II.2.[e] CHECKING
CONTROLLER BOARD.”
34
PROBLEM
[5] No water
comes from
POSSIBLE CAUSE a) Water Supply Line
REMEDY
1. Water pressure too low and 1. Check and get
water level in Water Tank recommended pressure.
Spray Tubes.
too low.
Water Pump b) Water Solenoid
will not start, or Valve
freeze cycle
time is too
short.
c) Water System d) Pump Motor
1. Dirty mesh filter or orifice
and water level in Water
Tank too low.
1. Water leaks.
2. Clogged.
1. Motor winding opened.
2. Bearing worn out.
3. Wiring to Pump Motor.
1. Clean.
1. Check connections for
water leaks, and replace.
2. Clean.
1. Replace.
2. Replace.
3. Check for loose
connection or open, and
replace.
e) Controller Board
[6] Fan Motor will a) Fan Motor
not start, or is
not operating.
4. Defective Capacitor.
4. Replace.
5. Defective or bound impeller. 5. Replace and clean.
6. Mechanical Seal worn out.
6. Check and replace.
1. Defective.
1. See “II.2. [e] CHECKING
1. Motor winding opened.
2. Bearing worn out.
3. Wiring to Fan Motor.
CONTROLLER BOARD.”
1. Replace.
2. Replace.
3. Check for loose
4. Defective Capacitor.
5. Fan blade bound.
1. Defective.
connection or open, and
replace.
4. Replace
5. Check and replace.
b) Controller Board
[7] All components a) Refrigerant
run but no ice
is produced.
1. Undercharged.
1. See “II.2. [e] CHECKING
CONTROLLER BOARD.”
1. Check for leaks and
recharge.
b) Compressor c) Hot Gas Solenoid
Valve d) Line Valve
2. Air or moisture trapped.
1. Defective valve.
1. Continues to open in freeze
Control opens and closes
frequently.
2. Replace Drier, and
recharge.
1. Replace.
1. Check and replace.
1. Check and replace e) Water Supply Line
freeze cycle.
1. Condenser water pressure 1. Check and get
[Water-cooled model too low or off and Pressure recommended pressure.
only]
cycle.
1. Continues to close in
35
2. EVAPORATOR IS FROZEN UP
PROBLEM POSSIBLE CAUSE REMEDY
[1] Freeze cycle
time is too
long.
[2] All ice formed
does not fall
harvest cycle.
a) Float Switch b) Water Solenoid
Valve c) Controller Board a) Evaporator
on Evaporator b) Water Supply Line
into bin in c) Water Solenoid
Valve
1. Leads short-circuit or
defective switch.
1. Check and replace.
2. Float does not move freely.
2. Clean or replace.
1. Diaphragm does not close.
1. Check for water leaks
1. Defective.
with icemaker off.
1. See “II.2[e] CHECKING
CONTROLLER BOARD.”
1. Clean.
1. Scaled up.
1. Water pressure too low.
1. Check and get
recommended pressure.
1. Dirty mesh filter or orifice.
1. Clean.
2. Diaphragm does not close.
2. Check for water leaks
1. Too cool.
with icemaker off.
1. Increase temperature.
d) Ambient and/or
water temperature e) Line Valve f) Thermistor g) Controller Board
1. Continues to open in
harvest cycle.
1. Check operation in
harvest cycle and replace.
1. Out of position or loose 1. See “V. 10. REMOVAL
attachment..
AND REPLACEMENT OF
1. Defrost Timer is set too
short.
THERMISTOR.”
1. Adjust longer, referring
to “II. 2. [d] CONTROLS
AND ADJUSTMENT, 2)
[3] Others a) Spray Tubes b) Water System c) Refrigerant d) Expansion Valve
2. Defective.
1. Clogged.
2. Out of position.
1. Dirty.
1. Undercharged.
Defrost Timer.”
2. See “II. 2.[e] CHECKING
CONTROLLER BOARD.”
1. Clean.
2. Place in position.
1. Clean.
1. Check for leaks and
recharge.
1. Place in position.
e) Hot Gas Solenoid
Valve f) Water Supply Line
1. Bulb out of position or
loose attachment.
2. Defective.
1. Coil winding opened.
2. Plunger does not move.
3. Wiring to Hot Gas Valve.
2. Replace.
1. Replace.
2. Replace.
3. Check for loose
connection or open, and
replace.
1. Increase Water Line size.
g) Water Filter (if
installed)
1. Too small; requires 3/8”
OD line dedicated per
machine.
1. Flow rate too small.
1. Replace with filter with
larger flow rate.
36
3. LOW ICE PRODUCTION
PROBLEM POSSIBLE CAUSE REMEDY
[1] Freeze cycle a) See chart 1 - [3], and check dirty Air Filter or Condenser, ambient or water
time is long.
temperature, water pressure, Water Regulator or refrigerant charge.
b) See chart 2 - [1], and check Float Switch, Water Solenoid Valve or Controller
Board.
[2] Harvest cycle a) See chart 2 - [2], and check Controller Board, Thermistor, Evaporator, ambient
time is long and/or water temperature, water supply line, Water Solenoid Valve, or Expansion
Valve.
4. ABNORMAL ICE
PROBLEM POSSIBLE CAUSE REMEDY
[1] Small Cube a) Ice Cube Guide 1. Out of position.
Circulated water falls into
1. Place in position.
bin.
b) See chart 1 - [5], and check water supply line, Water Solenoid Valve, water system,
Pump Motor or Controller Board.
c) Drain Valve 1. Dirty.
1. Clean.
[2] Cloudy or a) See chart 2 - [1] and - [3], and check Float Switch, Water Solenoid Valve,
irregular cube Controller Board, Spray Tubes, water system, refrigerant charge or Expansion
Valve.
b) Spray Guide c) Water Quality
1. Dirty.
1. High hardness or contains
impurities.
1. Clean.
1. Install a water filter or
softener.
5. OTHERS
PROBLEM POSSIBLE CAUSE
[1] Icemaker will a) Bin Control
not stop when Thermostat
bin is filled
with ice.
For mechanical bin control
[2] Abnormal
noise
see “II. 3. [c]”
a) Pump Motor b) Fan Motor
1. Set too cold.
2. Defective.
c) Compressor d) Refrigerant Lines
REMEDY
1. Adjust warmer.
2. Replace.
1. Bearings worn out.
1. Bearings worn out.
1. Replace.
1. Replace.
2. Fan blade deformed.
2. Replace fan blade.
3. Fan blade does not move 3. Replace.
freely.
1. Bearings worn out, or
cylinder valve broken.
2. Mounting pad out of
1. Replace.
2. Reinstall
position.
1. Rub or touch lines or other 1. Replace.
surfaces.
1. Plugged.
1. Clean.
[3] Ice in storage a) Bin Drain
bin often
melts.
37
V. REMOVAL AND REPLACEMENT OF COMPONENTS
IMPORTANT
Ensure all components, fasteners and thumbscrews are securely in place after the equipment is serviced.
IMPORTANT
1. The Polyol Ester (POE) oils used in R-404A units can absorb moisture quickly.
Therefore it is important to prevent moisture from entering the system when replacing or servicing parts.
2. Always install a new filter drier every time the sealed refrigeration system is opened.
3. Do not leave the system open for longer than 5 minutes when replacing or
servicing parts.
1. SERVICE FOR REFRIGERANT LINES
[a] REFRIGERANT RECOVERY
The icemaker unit is provided with two Refrigerant Access Valves one on the low-side and one on the high-side line. Using proper refrigerant practices recover the refrigerant from the Access Valves and store it in an approved container. Do not discharge the refrigerant into the atmosphere.
[b] EVACUATION AND RECHARGE [R-404A]
1) Attach Charging Hoses, a Service Manifold and a Vacuum Pump to the system. Be sure to connect charging hoses to both High and Low -side Access Valves.
IMPORTANT
The vacuum level and Vacuum Pump may be the same as those for current refrigerants. However, the rubber hose and gauge manifold to be used for evacuation and refrigerant charge should be exclusively for POE oils.
2) Turn on the Vacuum Pump. Never allow the oil in the Vacuum Pump to flow backward.
3) Allow the Vacuum Pump to pull down to a 29.9" Hg vacuum. Evacuating period depends on pump capacity.
38
4) Close the Low-side Valve and High-side Valve on the Service Manifold.
5) Disconnect the Vacuum Pump, and attach a Refrigerant Service Cylinder to the High-side line. Remember to loosen the connection, and purge the air from the Hose. See the
Nameplate for the required refrigerant charge. Hoshizaki recommends only virgin refrigerant or reclaimed refrigerant which meets ARI Standard No. 700-88 be used.
6) A liquid charge is recommended for charging an R-404A system. Invert the service cylinder. Open the High-side, Service Manifold Valve.
7) Allow the system to charge with liquid until the pressures balance.
8) If necessary, add any remaining charge to the system through the Low-side. Use a throttling valve or liquid dispensing device to add the remaining liquid charge through the Low-side access port with the unit running.
9) Close the two Refrigerant Access Valves, and disconnect the Hoses and Service Manifold.
10) Cap the Access Valves to prevent a possible leak.
2. BRAZING
DANGER
1. Refrigerant R-404A itself is not flammable at atmospheric pressure and
temperatures up to 176
° F.
2. Refrigerant R-404A itself is not explosive or poisonous. However, when
exposed to high temperatures (open flames) R-404A can be decomposed to form hydrofluoric acid and carbonyl fluoride both of which are hazardous.
3. Always recover the refrigerant and store it in an approved container. Do not
discharge the refrigerant into the atmosphere.
4. Do not use silver alloy or copper alloy containing Arsenic.
5. Do not use R-404A as a mixture with pressurized air for leak testing.
Refrigerant leaks can be detected by charging the unit with a little refrigerant, raising the pressure with nitrogen and using an electronic leak detector.
Note: All brazing-connections inside the Evaporator Case are clear-paint coated.
Sandpaper the brazing connections before unbrazing the components. Use a
good abrasive cloth to remove coating.
39
3. REMOVAL AND REPLACEMENT OF COMPRESSOR
IMPORTANT
Always install a new Drier every time the sealed refrigeration system is opened.
Do not replace the Drier until after all other repair or replacement has been made.
Note: When replacing a Compressor with a defective winding, be sure to install the new Start
Capacitor and Start Relay supplied with the replacement Compressor. Due to the ability of the POE oil in the compressor to absorb moisture quickly, the Compressor must not be opened more than 15 minutes for replacement or service. Do not mix lubricants of different compressors even if both are charged with R-404A, except when they use the same lubricant.
1) Turn off the power supply.
2) Remove the panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the Terminal Cover on the Compressor, and disconnect the Compressor Wiring.
5) Remove the Discharge and Suction Pipes using brazing equipment.
6) Remove the Hold-down Bolts, Washers and Rubber Grommets.
7) Slide and remove the Compressor. Unpack the new Compressor package. Install the new Compressor.
8) Attach the Rubber Grommets of the prior Compressor.
9) Sandpaper the Suction, Discharge and Process Pipes.
10) Place the Compressor in position, and secure it using the Bolts and Washers.
11) Remove plugs from the Suction, Discharge and Process Pipes.
12) Braze the Process, Suction and Discharge lines (Do not change this order), while purging with nitrogen gas flowing at the pressure 3 - 4 PSIG.
13) Install the new Filter Drier.
14) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.
40
15) Evacuate the system, and charge it with refrigerant. For air-cooled and water-cooled models, see the Nameplate for the required refrigerant charge. For remote air-cooled models, see the Charge Label in the machine compartment.
16) Connect the Terminals, and replace the Terminal Cover in its correct position.
17) Replace the panels in their correct positions.
18) Turn on the power supply.
41
4. REMOVAL AND REPLACEMENT OF DRIER
IMPORTANT
Always install a new Drier every time the sealed refrigeration system is opened. Do not replace the Drier until after all other repair or replacement has been made.
1) Turn off the power supply.
2) Remove the panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the Drier.
5) Install the new Drier, with the arrow on the Drier, in the direction of the refrigerant flow. Use nitrogen gas at the pressure of 3 - 4 PSIG when brazing the tubings.
6) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.
7) Evacuate the system, and charge it with refrigerant. For air-cooled and watercooled models, see the Nameplate for the required refrigerant charge. For remote air-cooled models, see the Charge Label in the machine compartment.
8) Replace the panels in their correct positions.
9) Turn on the power supply.
5. REMOVAL AND REPLACEMENT OF EXPANSION VALVE
IMPORTANT
Sometimes moisture in the refrigerant circuit exceeds the Drier capacity and freezes up at the Expansion Valve. Always install a new Drier every time the sealed refrigeration system is opened. Do not replace the Drier until after all other repair or replacement has been made.
1) Turn off the power supply.
2) Remove the panels.
42
3) Recover the refrigerant and store it in an approved container.
4) Remove the insulation and the Expansion Valve Bulb on the suction line.
5) Remove the Expansion Valve Cover, and disconnect the Expansion Valve using
brazing equipment.
6) Braze the new Expansion Valve, with nitrogen gas flowing at the pressure of 3 - 4
PSIG.
WARNING
Always protect the valve body by using a damp cloth to prevent the valve
from overheating. Do not braze with the valve body exceeding 250°F.
7) Install the new Drier.
8) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.
9) Evacuate the system, and charge it with refrigerant. For air-cooled and water-
cooled models, see the Nameplate for the required refrigerant charge. For remote
air-cooled models, see the Charge Label in the machine compartment.
10) Attach the Bulb to the suction line in position. Be sure to secure it with clamps and
to insulate it.
11) Place the new set of Expansion Valve Covers in position.
12) Replace the panels in their correct positions.
13) Turn on the power supply.
6. REMOVAL AND REPLACEMENT OF HOT GAS VALVE AND LINE
VALVE
CAUTION
Always use a copper tube of the same diameter and length when replacing the hot gas lines; otherwise the performance may be reduced.
43
IMPORTANT
Always install a new Drier every time the sealed refrigeration system is opened. Do not replace the Drier until after all other repair or replacement has been made.
1) Turn off the power supply.
2) Remove the panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the screw and the Solenoid.
5) Disconnect the Hot Gas Valve or Line Valve using brazing equipment.
6) Install the new valve.
WARNING
Always protect the valve body by using a damp cloth to prevent the valve from overheating. Do not braze with the valve body exceeding 250°F.
7) Install the new Drier.
8) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.
9) Evacuate the system, and charge it with refrigerant. For air-cooled and water-
cooled models, see the Nameplate for the required refrigerant charge. For remote
air-cooled models, see the Charge Label in the machine compartment.
10) Cut the leads of the Solenoid allowing enough lead length to reconnect using
closed end connectors.
11) Connect the new Solenoid leads.
12) Attach the Solenoid to the valve body, and secure it with a screw.
13) Replace the panels in their correct positions.
14) Turn on the power supply.
44
7. REMOVAL AND REPLACEMENT OF EVAPORATOR
IMPORTANT
Always install a new Drier every time the sealed refrigeration system is opened. Do not replace the Drier until after all other repairs or replacement have been made.
1) Turn off the power supply.
2) Remove the panels and the Top Insulation over the Evaporator.
3) Recover the refrigerant and store it in an approved container.
4) Remove the Spray Tubes and the Insulations at the “U” shaped notch where the refrigeration tubings go through the molded chassis.
5) Remove the Insulation Tube, and disconnect the Evaporator Inlet Tubing at the Tee
next to the Expansion Valve.
6) Lift up the Evaporator, and disconnect the Evaporator Outlet Tubing.
7) Install the new Evaporator.
8) Install the new Drier.
9) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.
10) Evacuate the system, and charge it with refrigerant. For air-cooled and water-
cooled models, see the Nameplate for the required refrigerant charge. For remote
air-cooled models, see the Charge Label in the machine compartment.
11) Replace the removed parts in the reverse order of which they were removed.
12) Replace the Top Insulation and the panels in their correct positions.
13) Turn on the power supply.
45
8. REMOVAL AND REPLACEMENT OF WATER REGULATING VALVE -
WATER-COOLED MODEL ONLY
IMPORTANT
Always install a new Drier every time the sealed refrigeration system is opened. Do not replace the Drier until after all other repair or replacement has been made.
1) Turn off the power supply.
2) Close the Water Supply Line Shut-off Valve.
3) Remove the panels.
4) Recover the refrigerant and store it in an approved container.
5) Disconnect the Capillary Tube at the Condenser outlet using brazing equipment.
6) Disconnect the Flare-connections of the valve.
7) Remove the screws and the valve from the Bracket.
8) Install the new valve, and braze the Capillary Tube.
9) Install the new Drier.
10) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles.
11) Evacuate the system, and charge it with refrigerant. See the Nameplate for the
required refrigerant charge.
12) Connect the Flare-connections.
13) Open the Water Supply Line Shut-off Valve.
14) Check for water leaks.
15) Replace the panels in their correct positions.
16) Turn on the power supply.
46
9. ADJUSTMENT OF WATER REGULATING VALVE - WATER-COOLED
MODEL ONLY
The Water Regulating Valve (also called “WATER REGULATOR”) is factory-adjusted.
No adjustment is required under normal use. Adjust the Water Regulator, if necessary, using the following procedures.
1) Attach a pressure gauge to the high-side line of the system. Or prepare a
thermometer to check for the condenser drain temperature.
2) Rotate the adjustment screw by using a flat blade screwdriver, so that the pressure
gauge shows the temperature specified in the table, 5 minutes after a freeze cycle
or icemaking process starts. When the pressure exceeds 270 PSIG, or the
condenser drain temperature exceeds the temperature range, rotate the adjustment
screw counterclockwise. See Fig. 1.
3) Check that the pressure or the condenser drain temperature holds a stable setting.
Fig. 1
47
10. REMOVAL AND REPLACEMENT OF THERMISTOR
CAUTION
1. Fragile, handle very carefully.
2. Always use a recommended sealant (High Thermal Conductive Type),
Model KE4560RTV manufactured by SHINETSU SILICONE, Part Code
60Y000-11, or Part Code 4A0683-01 or equivalent.
3. Always use a recommended foam insulation (Non-absorbent Type) or equivalent.
4. Do not shorten or cut the Thermistor leads when installing it.
1) Turn off the power supply.
2) Remove the panels.
3) Remove the Control Box Cover.
4) Disconnect the Thermistor leads from
the K3 Connector on the Controller Board.
Thermistor Lead Cable Tie
5) Remove the Plastic Cable Ties, Foam
Insulation, Thermistor Holder and
Thermistor. See Fig. 2.
Foam Insulation
Fig. 2
Thermistor Holder
6) Scrape away the old sealant on the
Thermistor Holder and the Suction Pipe.
7) Wipe off moisture or condensation on the Suction Pipe.
8) Smoothly apply recommended sealant (KE4560RTV, Part Code 60Y000-11 or
4A0683-01) to the Thermistor Holder concave.
9) Attach the new Thermistor to the Suction Pipe very carefully to prevent damage to
the leads. And secure it using the Thermistor Holder and recommended foam
insulation.
48
Note: For models with the Liquid Bypass, the Thermistor should be located
upstream from the Liquid Bypass outlet, and its end should be 4-3/4"
or more away from the outlet. See Fig. 3.
Min. 4-3/4"
Liquid Bypass
Flow
Fig. 3
10) Secure the insulation using the Plastic Cable Ties.
11) Connect the Thermistor leads through the bushing of the Control Box to the K3
Connector on the Controller Board.
Note: Do not cut the leads of the Thermistor while installing it.
12) Replace the Control Box Cover and the panels in their correct positions.
13) Turn on the power supply.
11. REMOVAL AND REPLACEMENT OF FAN MOTOR
Note: When replacing a Fan Motor with defective winding, it
is recommended that a new capacitor be installed.
1) Turn off the power supply.
2) Remove the panels.
3) Remove the Junction Box Cover from the remote condenser unit (Remote Air-cooled
model).
4) Remove the closed end connectors from the Fan Motor leads.
5) Remove the Fan Motor Bracket and Fan Motor.
49
6) Install the new Fan Motor, and replace the removed parts in the reverse order of
which they were removed.
7) Replace the panels in their correct positions.
8) Replace the Junction Box Cover in its correct position (Remote Air-cooled model).
9) Turn on the power supply.
12. REMOVAL AND REPLACEMENT OF WATER VALVE
1) Turn off the power supply.
2) Close the Water Supply Line Shut-off Valve.
3) Remove the Front Panel.
4) Remove the Valve Outlet Tubing by releasing the Clamp.
5) Remove the Bracket from the unit.
6) Remove the Fitting Nut and Water Valve.
7) Disconnect the Terminals from the Water Valve.
8) Install the new Water Valve, and replace the removed parts in the reverse order of
which they were removed.
9) Open the Water Supply Line Shut-off Valve.
10) Turn on the power supply.
11) Check for leaks.
12) Replace the Front Panel in its correct position.
13. REMOVAL AND REPLACEMENT OF PUMP MOTOR
1) Turn off the power supply.
2) Remove the Front Panel.
50
3) Remove the Base Cover.
4) Drain the Water Tank by removing one end of the Pump Tubing.
5) Replace the removed parts in their correct positions.
6) Disconnect the Pump Suction and Discharge Hoses.
7) Remove the screws and the Pump Motor Bracket.
8) Remove the closed end connectors from the Pump Motor leads.
9) Remove the two screws and the Pump Motor Bracket.
10) Remove the Pump Housing, and check the Impeller.
11) If the Impeller is defective, install a new Impeller.
12) Install the new motor or new parts, and replace the removed parts in the reverse
order of which they were removed.
13) Turn on the power supply, and check for leaks.
14) Replace the Base Cover in its correct position.
15) Replace the Front Panel in its correct position.
14. REMOVAL AND REPLACEMENT OF SPRAY TUBES
1) Turn off the power supply.
2) Remove the Front Panel and the Insulation Panel.
3) Remove the Rubber Hoses from the Spray Tubes (Water Supply Pipe).
4) Release the Clamps, and disconnect the Rubber Hoses.
5) Remove the Spray Tubes by squeezing the side tabs.
6) Install the new Spray Tubes, and replace the removed parts in the reverse order of
which they were removed.
7) Replace the panels in their correct positions.
8) Turn on the power supply.
51
VI. CLEANING AND MAINTENANCE INSTRUCTIONS
IMPORTANT
Ensure all components, fasteners and thumbscrews are securely in place after any maintenance or cleaning is done to the equipment.
1. PREPARING THE ICEMAKER FOR LONG STORAGE
WARNING
When shutting off the icemaker for an extended time, drain out all water from the water tank and remove the ice from the Storage Bin. The Storage Bin should be cleaned and dried. Drain the icemaker to prevent damage to the water supply line at sub-freezing temperatures, using air or carbon dioxide.
Shut off the icemaker until the proper ambient temperature is resumed.
• When the icemaker is not used for two or three days, it is sufficient to only move the
Control Switch to the “OFF” position, unless the icemaker will be at sub-freezing temperatures.
[1] On water-cooled model only, first remove the water from the water-cooled condenser:
1) Remove the Front Panel.
2) Move the Control Switch, on the Control Box, to the “OFF” position.
3) Wait 3 minutes.
4) Move the Control Switch to the “ICE” position.
5) Allow 5 minutes for the icemaker to fill with water and the Water Pump to start
operating.
6) Close the Water-cooled Condenser Water Supply Line Shut-off Valve.
7) Open the Drain Valve for the water-cooled condenser water supply line.
8) Allow the line to drain by gravity.
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9) Attach compressed air or carbon dioxide supply to the Condenser Water Line Drain
Valve.
10) Quickly blow the water-cooled Condenser out, using compressed air or carbon
[2] Remove the water from the potable water supply line:
1) Remove the Front Panel. (Except water-cooled model)
2) Move the Control Switch, on the Control Box, to the “OFF” position.
3) Wait 3 minutes.
4) Close the Potable Water Supply Line Shut-off Valve and open the Potable Water
Supply Line Drain Valve.
5) Allow the line to drain by gravity.
6) Attach compressed air or carbon dioxide supply to the Potable Water Line Drain Valve.
7) Move the Control Switch to the “ICE” position.
8) Blow the potable water line out using compressed air or carbon dioxide.
[3] Drain the Potable Water Tank:
1) Turn off the power supply.
2) Move the Control Switch to the “OFF”
position.
3) Drain the Water Tank by removing the
base cover and one end of the pump
tubing. See Fig. 4.
4) Replace the removed parts in their correct
positions.
5) Remove all ice from the Storage Bin, and
clean the Storage Bin.
6) Replace the Front Panel in its correct
position.
7) Close the Drain Valve.
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Fig. 4
2. CLEANING
IMPORTANT
Ensure all components, fasteners and thumbscrews are securely in place after any maintenance or cleaning is done to the equipment.
WARNING
1. HOSHIZAKI recommends cleaning this unit at least once a year. More frequent cleaning, however, may be required in some existing water conditions.
2. To prevent injury to individuals and damage to the icemaker, do not use ammonia type cleaners.
3. Always wear liquid-proof gloves for safe handling of the cleaning and sanitizing solution. This will prevent irritation in case the solution comes into contact with skin.
IMPORTANT
1. The Cleaning Valve is used to allow solution flow to the inside of the
Evaporator during the cleaning and sanitizing operation. It should be closed for all icemaking operation. The Compressor will not operate unless this valve is completely closed.
2. To open the Cleaning Valve, the Valve Handle should be parallel to the
valve body. To close the valve, the Valve Handle should be at a right
angle to the valve body.
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[a] CLEANING PROCEDURE
1) Dilute 16 fl. oz. of the recommended cleaner Hoshizaki “Scale Away” or
“LIME-A-WAY” (Economics Laboratory, Inc.) with 3 gal. of water.
2) Remove all ice from the Evaporator and the Storage Bin.
Note: To remove cubes on the Evaporator, turn off the power supply and turn
it on after 3 minutes. The defrost cycle starts and the cubes will be
removed from the Evaporator.
3) Turn off the power supply.
4) Remove the Front Panel and then remove the Insulation Panel, by first removing
the thumbscrew, lifting the panel slightly and pulling it toward you.
5) Remove the Base Cover.
6) Drain the Water Tank by removing one end of the Pump Tubing. See Fig. 4.
7) Replace the removed parts in their correct positions.
8) Pour the cleaning solution into the Water Tank.
9) Fully open the Cleaning Valve on the left side wall of the machine compartment.
10) Move the Control Switch, on the Control Box, to the “WASH” position.
11) Replace the Insulation Panel and the Front Panel in their correct positions.
12) Turn on the power supply, and start the washing process.
13) Turn off the power supply after 30 minutes.
14) Remove the Front Panel and the Insulation Panel.
15) Drain the Water Tank. (See the above step 6).
16) Replace the removed parts in their correct positions.
17) Move the Control Switch to the “ICE” position.
18) Close the Cleaning Valve.
Note: The icemaker will not operate unless the Cleaning Valve is completely closed.
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19) Replace the Front Panel in its correct position.
20) Turn on the power supply to fill the Water Tank with water.
21) Turn off the power supply after 3 minutes.
22) Remove the Front Panel, and fully open the Cleaning Valve.
23) Move the Control Switch to the “Wash” position.
24) Replace the Front Panel in its correct position.
25) Turn on the power supply to rise off the cleaning solution.
26) Turn off the power supply after 5 minutes.
27) Remove the Front Panel and Insulation Panel.
28) Drain the Water Tank by removing one end of the Pump Tubing. See Fig. 4.
29) Replace the removed parts in their correct positions.
Note: Do not replace the InsulationPanel when you proceed to
“[b] SANITIZING PROCEDURE.”
28) Repeat the above steps 17 through 29 three more times to rinse thoroughly.
Note: If you do not sanitize the icemaker, go to step 9 in “[b] SANITIZING
PROCEDURE.”
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[b] SANITIZING PROCEDURE - Following Cleaning Procedure
1) Dilute a 5.25 % Sodium Hypochlorite solution with water (Add 1.5 fl. oz. of sanitizer to
3 gal. of water).
2) Remove the Insulation Panel, if it is in its usual position.
3) Pour the sanitizing solution into the Water Tank.
4) Replace the Insulation Panel and the Front Panel in their correct positions.
Note: Make sure that the Control Switch is in the “WASH” position and the
Cleaning Valve is open.
5) Turn on the power supply, and start the sanitizing process.
6) Turn off the power supply after 15 minutes.
7) Remove the Front Panel and if necessary, the Insulation Panel.
8) Drain the Water Tank. See the above step 5) in “[a] CLEANING PROCEDURE.”
9) Replace the removed parts and the Insulation Panel in their correct position.
10) Repeat the above steps 17) through 29) in “[a] CLEANING PROCEDURE” two
times to rinse thoroughly.
11) Close the Cleaning Valve.
12) Move the Control Switch to the “ICE” position.
13) Replace the Front Panel in its correct position.
14) Clean the Storage Bin with water.
15) Turn on the power supply, and start the automatic icemaking process.
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3. MAINTENANCE
IMPORTANT
This icemaker must be maintained individually, referring to the instruction manual and labels provided with the icemaker.
1) Stainless Steel Exterior
To prevent corrosion, wipe the exterior occasionally with a clean and soft cloth.
Use a damp cloth containing a neutral cleaner to wipe off oil or dirt build up.
2) Storage Bin and Scoop
• Wash your hands before removing ice. Use the plastic scoop provided.
• The Storage Bin is for ice use only. Do not store anything else in the bin.
• Keep the scoop clean. Clean it by using a neutral cleaner and rinse thoroughly.
• Clean the bin liner by using a neutral cleaner. Rinse thoroughly after cleaning.
3) Condenser (Except water-cooled model)
Check the Condenser once a year, and clean, if required, by using a brush or vacuum cleaner. More frequent cleaning may be required depending on the
location of the icemaker.
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