Hoshizaki KM-900MRH Service Manual

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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

Please review this manual. It should be read carefully before the icemaker is serviced or maintenance operations are 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-900MAH (Air-cooled) .................................................................................. 5

2a. KM-900MWH (Water-cooled), Serial # L00001D-M20500D ............................. 6

2b. KM-900MWH (Water-cooled), Serial # M30501D-- .......................................... 7

3. KM-900MRH (Remote air-cooled) .................................................................... 8

4. KM-900MRH3 (Remote air-cooled 3 phase) .................................................... 9

5. CONDENSING UNIT, URC-12F ..................................................................... 10

II. GENERAL INFORMATION .................................................................................... 12

1. CONSTRUCTION ............................................................................................. 12

[a] KM-900MAH (Air-cooled) ............................................................................ 12

[b] KM-900MWH (Water-cooled) ..................................................................... 13

[c] KM-900MRH (Remote air-cooled) ............................................................... 14

[d] KM-900MRH3 (Remote air-cooled 3 phase) ............................................... 15

2. CONTROLLER BOARD .................................................................................... 16

[a] SOLID-STATE CONTROL .......................................................................... 16

[b] CONTROLLER BOARD .............................................................................. 16

[c] SEQUENCE ................................................................................................ 20

[d] CONTROLS AND ADJUSTMENTS ............................................................. 23

[e] CHECKING CONTROLLER BOARD .......................................................... 27

3. MECHANICAL BIN CONTROL.......................................................................... 28

[a] PROXIMITY SWITCH................................................................................. 28

[b] EXPLANATION OF OPERATION .............................................................. 28

[c]

TROUBLESHOOTING................................................................................ 29

III. TECHNICAL INFORMATION ............................................................................... 30

1. WATER CIRCUIT AND REFRIGERANT CIRCUIT............................................ 30

[a] KM-900MAH (Air-cooled) ............................................................................ 30

[b] KM-900MWH (Water-cooled) ..................................................................... 31

[c] KM-900MRH (Remote air-cooled) ...................................................................

and KM-900MRH3 (Remote air-cooled 3 phase)........................................ 32

2. WIRING DIAGRAMS ........................................................................................ 33

[a] KM-900MAH (Air-cooled) ............................................................................ 33

[b] KM-900MWH (Water-cooled) ..................................................................... 35

[c] KM-900MRH (Remote air-cooled) ............................................................... 37

[d] KM-900MRH3 (Remote air-cooled 3 phase) ............................................... 39

3. TIMING CHART ................................................................................................ 41

4. PERFORMANCE DATA .......................................................................................43

[a] KM-900MAH (Air-cooled) ............................................................................... 43

[b] KM-900MWH (Water-cooled), Serial # L00001D-M20500D .......................... 44

[c] KM-900MWH (Water-cooled), Serial # M30501D--........................................ 45

[d] KM-900MRH (Remote air-cooled) ................................................................. 46

[e] KM-900MRH3 (Remote air-cooled 3 phase) .................................................. 47

IV. SERVICE DIAGNOSIS ........................................................................................... 48

1. NO ICE PRODUCTION........................................................................................ 48

2. EVAPORATOR IS FROZEN UP .......................................................................... 51

3. LOW ICE PRODUCTION ..................................................................................... 51

4. ABNORMAL ICE .................................................................................................. 52

5. OTHERS .............................................................................................................. 52

V. REMOVAL AND REPLACEMENT OF COMPONENTS ........................................... 53

1. SERVICE FOR REFRIGERANT LINES ............................................................... 53

[a] REFRIGERANT RECOVERY ......................................................................... 53

[b] EVACUATION AND RECHARGE [R-404A] ................................................... 53

2. BRAZING ............................................................................................................. 54

3. REMOVAL AND REPLACEMENT OF COMPRESSOR ....................................... 55

4. REMOVAL AND REPLACEMENT OF DRIER ..................................................... 57

5. REMOVAL AND REPLACEMENT OF EXPANSION VALVE ............................... 57

6. REMOVAL AND REPLACEMENT OF HOT GAS VALVE AND................................

LINE VALVE ....................................................................................................... 58

7. REMOVAL AND REPLACEMENT OF EVAPORATOR ........................................ 60

8. REMOVAL AND REPLACEMENT OF WATER-REGULATING VALVE ...................

- WATER COOLED MODEL ONLY .................................................................... 61

9. ADJUSTMENT OF WATER-REGULATING VALVE.................................................

- WATER COOLED MODEL ONLY .................................................................... 62

10. REMOVAL AND REPLACEMENT OF CONDENSING PRESSURE .........................

REGULATOR (C.P.R.) - REMOTE AIR-COOLED MODEL ONLY .................. 63

11. REMOVAL AND REPLACEMENT OF THERMISTOR.......................................... 64

12. REMOVAL AND REPLACEMENT OF FAN MOTOR ........................................... 65

13. REMOVAL AND REPLACEMENT OF WATER VALVE ........................................ 66

14. REMOVAL AND REPLACEMENT OF PUMP MOTOR ........................................ 66

15. REMOVAL AND REPLACEMENT OF SPRAY TUBES ........................................ 67

VI. MAINTENANCE AND CLEANING INSTRUCTIONS ............................................... 68

1. PREPARING THE ICEMAKER FOR LONG STORAGE ...................................... 68

2. CLEANING ........................................................................................................... 70

[a] CLEANING PROCEDURE ............................................................................. 71

[b] SANITIZING PROCEDURE ........................................................................... 72

3. MAINTENANCE ................................................................................................... 73

I. SPECIFICATIONS

1. KM-900MAH

AC SUPPLY VOLTAGE 208/230/60/1 ( 3 wire with neutral for 115V ) AMPERAGE 11 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CI RCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient W ATER TEMP. (°F) PER 24 HR. Temp.(°F)507090 lbs./ day ( kg/day ) 70 *838 (380) 804 (365) 759 (344) Reference without *marks 80 812 (368) 759 (344) 715 (324)

90 804 (365) *721 (327) 676 (306)

100 795 (361) 710 (322) 634 (288) SHAPE OF ICE Cresc ent Cube ICE P RODUCTION PER CYCLE 14.3 lbs. ( 6.5 kg ) 720 pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70° F 70/50° F ELECTRIC W (kWH/100 lbs.) 1965 (6.6) 1783 (5.1) WATER gal./24HR (gal./100 lbs.) 244 (31.5) 472 (56.3) EXTERIOR DIMENSIONS (WxDxH) 30" x 27-3/8" x 37-7/16" (762 x 695 x 950 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 216 lbs. ( 98 kg ), S hipping 282 lbs. (128 kg) CONNECTIONS - ELECTRIC Permanent - Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

3/8" OD Pipe CUBE CONTROL SYSTEM Float Switch HARVESTING CONTROL SYSTEM Hot Gas and W ater, Thermistor and Timer ICE MAKI NG WATER CONTROL Timer Controlled. Overflow Pipe COOLING WATER CONTROL N/A BIN CONTROL SYSTEM Proximity Switch with Delay COMPRESSOR Hermetic, Model CS14K6E-PFV CONDENSER Air-cooled, Fin and tube ty pe EVAPORATOR Vertical type, Stainless Steel and Copper REFRIGERANT CONTROL Thermostatic Expansion Valve REFRIGERANT CHARGE R-404A, 3 lb. 7 oz. ( 1550 g ) DESI GN PRESSURE High 467 PSIG, Low 230 PSIG P.C. BOARD CI RCUIT PROTECTION High Voltage Cut-out ( Internal ) COMPRESSOR PROTECTION Auto-r eset Overload Protector ( Internal ) REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch LOW WATER PROTECTION Float Switch ACCESSORIES -SUPPLIED N/A

-REQUIRED Ice Storage Bi n OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 V

AMBIENT TEMP. 45 -100° F W ATER SUPPLY TEMP. 45 - 90° F WATER SUPPLY PRESSURE 10 - 113 PSIG

We reserve the right to make changes in specifications and design without prior notice.

2a. KM-900MWH

AC SUPPLY VOLTAGE 208-230/60/1 (3 wire with neutral for 115 V) AMPERAGE 10.2 A MI NIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A

APPROXIMATE ICE PRODUCTION Ambient W ATER TEMP. (°F) PER 24 HR. Temp. (°F ) 5 0 70 90 lbs./day ( kg/ day ) 70 *853 (387) 836 (379) 787 (357) Reference without *marks 80 840 (381) 813 (369) 750 (340)

90 836 (379) 794 (360) 736 (334)

100 818 (371) 780 (354) 683 (310) SHAPE OF ICE Cresc ent Cube ICE P RODUCTION PER CYCLE 14.3 lbs. ( 6.5 kg ) 720 pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70° F 70/50° F ELECTRIC W (kWH/100 lbs.) 1775 (5. 3) 1768 (5. 0) WA TER gal./24HR (gal. /100 lbs.) 256 (32.2) 409 (47. 9) WA TER COOLED CONDENSER 1024 (129) 580 (68) gal./24HR (gal./100 lbs. ) EXTERIOR DIMENSIONS (WxDxH) 30" x 27- 3/8" x 37 7/16" ( 762 x 695 x 950 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) W E IGHT Net 211 lbs. ( 96 kg ), Shipping 277 lbs. ( 126 kg ) CONNECTIONS - ELECTRIC Permanent - Connec ti on

- WATER SUPPLY Inlet 1/ 2" FPT Condenser Inlet 1/2" FPT

- DRAIN Outlet 3/ 4" FPT Condenser Outlet 3/8" FPT

3/8" OD Pi pe CUBE CONTROL SYSTEM Float Switch HARVESTING CONTROL SYSTEM Hot Gas and Water, Thermistor and Timer ICE MAKI NG WATER CONTROL Timer Controlled. Overflow Pipe COOLING WATER CONTROL Pressure Regulator BIN CONTROL SYSTEM Pr oximity Switch with Delay COMPRESSOR Hermetic, Model CS14K6E-PFV CONDENSER W ater-c ooled, Tube in tube type EVAPORATOR Verti cal type, Stainless Steel and Copper REFRIGERANT CONTROL Thermostatic Expansion Valve REFRIGERANT CHARGE R-404A, 1 lb 7 oz. ( 650 g ) DESIGN PRESSURE High 427 PSIG, Low 230 PSIG P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out ( Internal ) COMPRESSOR PROTECTION Auto-r eset Overload Protector ( Internal ) REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch LOW WATER PROTECTION Float Switch ACCESSORIES -S UPPLIED N/A

-REQUIRED Ice Storage Bin OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 V

AMBIENT TEMP. 45 -100° F

W A TER SUPPLY TEMP. 45 - 90° F

W A TER SUPPLY PRESSURE 10 - 113 PSIG

Beginni ng S erial No. L00001D

Ending Serial No. M20500D

We reserve the right to make changes in specifications and design without prior notice.

2b. KM-900MWH

Beginning Seri al No. M30501D

AC SUPPLY VOLTAGE 208-230/60/ 1 (3 wire with neutral for 115V) AMPERAGE 10.2 A ( 5 Min. Fr eeze AT 104°F / WT 80°F) MI NIMUM CIRCUIT AMP ACITY 15 A MAXIMUM FUSE SIZE 15 A APPROXIMATE ICE PRODUCTION Ambient W ATER TEMP. (°F) PER 24 HR. Temp. (°F ) 50 70 9 0 lbs./day ( kg/day ) 70 *846 (384) 830 (376) 787 (357) Reference without *marks 80 833 (378) 808 (367) 754 (342)

90 830 (376) *790 (358) 740 (336)

100 814 (369) 778 (353) 694 (315) SHAPE OF ICE Cresc ent Cube ICE PRODUCTION PER CYCLE 14.3 lbs. ( 6.5 kg ) 720 pcs. APPROXIMATE STORAGE C APACITY N/A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W ( kWH/100 lbs.) 1700 (5.2) 1692 (4.8) W A TER gal./24HR (gal./100 lbs.) 269 ( 34.0) 418 (49.4) W A TER COOLED CONDENSER 916 (116) 491 (58) gal./24HR (gal./ 100 lbs. ) EXTERIOR DIMENSI ONS (WxDxH) 30" x 27-3/8" x 37 7/16" (762 x 695 x 950 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 211 lbs. ( 96 kg ), S hipping 277 lbs. ( 126 kg ) CONNECTIONS - ELECTRIC Permanent - Connection

- WATER SUPPLY Inlet 1/2" FPT Condenser Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT Condenser Outlet 3/8" FPT

3/8" OD Pi pe CUBE CONTROL SYSTEM Float Switch HARVESTING C ONTROL SYSTEM Hot Gas and W ater , Thermistor and Timer ICE MAKI NG WATER CONTROL Timer Controlled. Overflow Pipe COOLING WATER CONTROL Pressure Regulator BIN CONTROL SYSTEM Proximity Switch with Delay COMPRESSOR Hermetic , Model CS14K6E-PFV-237 CONDENSER W ater-cooled, Tube in tube type EVAPORATOR Verti cal type, Stai nless Steel and Copper REFRIGERANT CONTROL Thermostatic Expansion Valve REFRIGERANT CHARGE R-404A, 1 lb. 14 oz. ( 850 g ) DESI GN PRESSURE High 427 PSIG, Low 230 PSIG P.C. BOARD CIRCUIT PROTECTION High Voltage Cut-out ( I nternal ) 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

W ATER SUPPLY TEMP. 45 - 90° F

W A TER SUPPLY PRESSURE 10 - 113 PSIG

We reserve the right to make changes in specifications and design without prior notice.

3. KM-900MRH

AC SUP PLY V OLTAGE 208-230/60/ 1 (3 wire wi t h neutral for 115V) AMPERAGE 12.5 A ( 5 Mi n. Freeze A T 104°F / WT 80°F) MINIMUM CIRCUIT AM PACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR. Tem p.(°F ) 50 70 90 lbs ./day ( kg/ day ) 70 *835 (379) 817 (370) 786 (356) Reference without *mark s 80 821 (372) 792 (359) 758 (344)

90 817 (370) *772 (350) 739 (335)

100 808 (367) 764 (347) 708 (321) SHAPE OF ICE Crescent Cube ICE P RO DUCTION P ER CYCLE 14. 3 l b s. ( 6.5 kg ) 720 pcs. APPROXIMATE STORAGE CAPACITY N/A ELE CTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELE CTRIC W (kW H/ 100 l bs.) 2060 (6.4) 2005 (6.0) W A TER gal./24HR (gal. /100 lbs.) 255 (33.0) 450 (53.9) EXTERIOR DIMENS IONS (Wx Dx H) 30" x 27-3/8" x 37-7/16" (762 x 695 x 950 mm) EXTERIOR FINISH St ai nl ess Steel, Galvanized St eel (Rear) W E IGHT Net 216 lbs. ( 98 kg ), S hi pping 282 l bs. ( 128 kg ) CONNECTIONS - ELECTRIC P erm anent - Connecti on

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

Condensin g Pressu re Re gu l a tor on URC-12 F REFRIGERA NT CHARGE R-404A, 9 lbs. 14 oz. ( 4500 g )

( Icemaker 5 lbs. 8 oz. Cond. Unit 4 l b. 6 oz. ) DESIGN PRE SSURE High 467 PSIG, Low 230 P S IG P.C. BOARD CIRCUIT PROTE CTION Hi gh Voltage Cut-out ( Inte rna l ) COMPRESSOR PROTECTION Auto-reset Overload Protector ( Internal ) REF RIGERANT CIRCUIT PROTECTION A uto-reset High P ressure Control Switch LOW WATER PROTECTION Float Switch ACCESSORIES -SUPPLIED N/A

-REQUIRED Ic e Storage B i n, Rem ote Condenser Unit OPE RA TING CONDITIONS VOLTAGE RA NGE 187 - 253 V

AM B IE NT TEM P . 45 -100° F

W A TER SUPPLY TEMP . 45 - 90° F

WATER SUPPLY PRESSURE 10 - 113 PSIG

We reserve the right to make changes in specifications and design without prior notice.

4. KM-900MRH3

AC SUPPLY VOLTAGE 208-230/60/3 AMPERAGE 6.5 A ( 5 Min. Fr eeze AT 104°F / WT 80°F) MINIMUM CI RCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROX IMATE ICE PRODUCTION Ambient WATER TEMP. (° F) PER 24 HR. Temp.(°F)507090 lbs./ day ( kg/day ) 70 *842 (382) 826 (375) 784 (356) Reference without *marks 80 830 (377) 806 (366) 753 (341)

90 826 (375) *789 (358) 739 (335)

100 811 (368) 777 ( 353) 694 (315) SHAPE OF ICE Cresc ent Cube ICE P RODUCTION PER CYCLE 14.3 lbs. (6.5 kg ) 720 pcs. APPROXIMATE STORAGE CAPACITY N/A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs. ) 2070 (6.3) 2000 (5.7) WATER gal./24HR (gal./100 lbs.) 264 (33.4) 454 (53.9) EXTERIOR DIMENSIONS (WxDxH) 30" x 27-3/8" x 37-7/16" (762 x 695 x 950 mm) EXTERIOR FINISH Stainless Steel, Galvanized Steel (Rear) WEIGHT Net 216 lbs. ( 98 kg ), S hipping 282 lbs. ( 128 kg ) CONNECTIONS - ELECTRIC Permanent - Connection

- WATER SUPPLY Inlet 1/2" FPT

- DRAIN Outlet 3/4" FPT

Condensing Pressure Regulator on URC-12F REFRIGERANT CHARGE R-404A, 9 lbs. 14 oz. ( 4500 g )

( Icemaker 5 lbs. 8 oz. Cond. Unit 4 lb. 6 oz. ) DESI GN PRESSURE High 467 PSIG, Low 230 PSIG P.C. BOARD CI RCUIT PROTECTION High Voltage Cut-out ( Internal ) COMPRESSOR PROTECTION Auto-reset Overload Pr otector ( Internal ) REFRIGERANT CIRCUIT PROTECTION Auto-reset High Pressure Control Switch LOW WATER PROTECTION Float Switch ACCESSORIES -SUPPLIED N/A

-REQUIRED Ice Storage Bi n, Remote Condenser Unit OPERATING CONDITIONS VOLTAGE RANGE 187 - 253 V

AMBIENT TEMP. 45 -100° F

W ATER SUPPLY TEMP. 45 - 90° F

WATER SUPPLY PRESSURE 10 - 113 PSIG

We reserve the right to make changes in specifications and design without prior notice.

5. CONDENSING UNIT

URC-12F

MODEL: URC-12F

SPECIFICATIONS

EXTERIOR

DIMENSIONS (W x D x H)

REFRIGERANT CHARGE

URC-12F

WEIGHT

CONNECTIONS

REFRIGERANT ELECTRICAL

CONDENSER

HEAD PRESSURE CONTROL

AMBIENT CONDITION

Galvanized Steel

35 - 11/16” x 15-11/16” x 21-15/16” (907.2 x 398 x 557.8 mm)

R404A 4 lbs. 7 oz. (2000 g)

Net 80 lbs. (36 kg) Shipping 87 lbs. (39 kg)

One Shot Couplings (Aeroquip) Permanent Connection

Air-cooled

Condensing Pressure Regulator

Min. -20°F - Max. +122°F (-29°C to +50°C) Outdoor use

II. GENERAL INFORMATION

1. CONSTRUCTION

[a] KM-900MAH

Models with Thermostat

Models with Mechanical Bin Control

[b] KM-900MWH

Models with Thermostat

Models with Mechanical Bin Control

[c] KM-900MRH

Models with Thermostat

Models with Mechanical Bin Control

[d] KM-900MRH3

Models with Thermostat

Models with Mechanical Bin Control

2. CONTROLLER BOARD

[a] SOLID-STATE CONTROL

1) A HOSHIZAKI exclusive solid-state control is employed in KM-900MAH, KM-900MWH, KM-900MRH and KM-900MRH3 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.

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.

The green LED’s 1-4 represent the corresponding relays and energize and sequence 5 seconds from initial start-up as follows:

Sequence Step LED’s on Length: Min. Max. Avg.

1 Minute Fill Cycle LED4 60 sec. Harvest Cycle LED1, 4, & 2 2 min. 20 min. 3-5 min. Freeze Cycle LED1 5 min. 60 min. 30-35 min. Reverse Pump Out LED1, 3, & 2 10 sec. 20 sec. 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.

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)

[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.

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.

IMPORTANT

Water Valve opening is limited to 6 minutes.

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.

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.

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.

+ 51 hidden pages

Hoshizaki KM-900MRH Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual