Hoshizaki KM-501MWH, KM-501MRH, KM-501MAH User Manual

HoshizakiHoshizaki America, Inc.

Modular Crescent Cuber

Models

KM-501MAH

KM-501MWH

KM-501MRH

“A Superior Degree

of Reliability”

SERVICE MANUAL

www.hoshizaki.com

		Number: 73137
		Issued: 10-16-2006
		Revised: 3-27-2007

IMPORTANT

Only qualified service technicians should attempt to service or maintain this icemaker. No such 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: [phone] Technical Service

[phone]

Fax: [phone]

[phone]

Web Site: www.hoshizaki.com

NOTE: To expedite assistance, all correspondence/communication MUST include the following information:

•Model Number

•Serial Number

•Complete and detailed explanation of the problem

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
I. Specifications......................................................................................................................	5
A. Icemaker........................................................................................................................	5
1. KM-501MAH (air-cooled).........................................................................................	5
2. KM-501MWH (water-cooled)....................................................................................	6
3. KM-501MRH (remote air-cooled).............................................................................	7
B. Condensing Unit............................................................................................................	8
1. URC-6F....................................................................................................................	8
II. General Information..........................................................................................................	10
A. Construction................................................................................................................	10
1. KM-501MAH (air-cooled).......................................................................................	10
2. KM-501MWH (water-cooled)..................................................................................	11
3. KM-501MRH (remote air-cooled)...........................................................................	12
B. Sequence of Operation................................................................................................	13
1. One Minute Fill Cycle.............................................................................................	13
2. Initial Harvest Cycle ..............................................................................................	13
3. Freeze Cycle .........................................................................................................	13
4. Pump-Out Cycle ....................................................................................................	13
5. Normal Harvest Cycle ...........................................................................................	13
C. Control Board..............................................................................................................	15
1. Control Board Layout.............................................................................................	16
2. Features.................................................................................................................	17
a) Maximum Water Supply Period – 6 minutes.......................................................	17
b) Harvest Backup Timer and Freeze Timer............................................................	17
c) High Temperature Safety.....................................................................................	17
d) Low Water Safety................................................................................................	17
e) High Voltage and Low Voltage Cut-outs..............................................................	17
f) LED Lights and Audible Alarm Safeties...............................................................	18
3. Controls and Adjustments......................................................................................	19
a) Default Dip Switch Settings.................................................................................	19
b) Harvest Control – Thermistor..............................................................................	19
c) Harvest Timer (dip switch 1 & 2).........................................................................	20
d) Pump-Out Timer (dip switch 3 & 4).....................................................................	20
e) Pump-Out Frequency Control (dip switch 5 & 6).................................................	21
f) Freeze Timer (dip switch 9 & 10)..........................................................................	21
g) Bin Control..........................................................................................................	21
4. Control Board Check Procedure............................................................................	22
5. Control Board Replacement...................................................................................	22

III. Technical Information.......................................................................................................	23
A. Water Circuit and Refrigeration Circuit........................................................................	23
1. KM-501MAH (air-cooled).......................................................................................	23
2. KM-501MWH (water-cooled)..................................................................................	24
3. KM-501MRH (remote air-cooled)...........................................................................	25
B. Wiring Diagrams..........................................................................................................	26
1. KM-501MAH (air-cooled) and KM-501MWH (water-cooled)..................................	26
2. KM-501MRH (remote air-cooled)...........................................................................	27
C. Timing Chart................................................................................................................	28
D. Performance Data........................................................................................................	30
1. KM-501MAH (air-cooled).......................................................................................	30
2. KM-501MWH (water-cooled)..................................................................................	31
3. KM-501MRH (remote air-cooled)...........................................................................	32
IV. Service Diagnosis............................................................................................................	33
A. 10-Minute KM Diagnostic Procedure ..........................................................................	33
B. Diagnostic Charts........................................................................................................	34
1. No Ice Production...................................................................................................	34
2. Evaporator is Frozen Up.........................................................................................	38
3. Low Ice Production.................................................................................................	39
4. Abnormal Ice..........................................................................................................	39
5. Other......................................................................................................................	39
V. Removal and Replacement of Components.....................................................................	41
A. Service for Refrigerant Lines.......................................................................................	41
1. Refrigerant Recovery.............................................................................................	41
2. Evacuation and Recharge (R-404A)......................................................................	41
B. Brazing.........................................................................................................................	42
C. Removal and Replacement of Compressor.................................................................	42
D. Removal and Replacement of Drier.............................................................................	43
E. Removal and Replacement of Expansion Valve..........................................................	44
F. Removal and Replacement of Hot Gas Valve and Line Valve .....................................	44
G. Removal and Replacement of Evaporator...................................................................	45
H. Removal and Replacement of Water Regulating Valve - Water Cooled Model Only...	46
I. Adjustment of Water Regulating Valve - Water-Cooled Model Only..............................	46
J. Removal and Replacement of Headmaster (Condensing Pressure Regulator - C.P.R.)
- Remote Air-Cooled Model Only..............................................................................	47
K. Removal and Replacement of Thermistor...................................................................	48
L. Removal and Replacement of Fan Motor.....................................................................	49
M. Removal and Replacement of Inlet Water Valve.........................................................	49
N. Removal and Replacement of Pump Motor.................................................................	49
O. Removal and Replacement of Spray Tubes.................................................................	50
VI. Cleaning and Maintenance Instructions..........................................................................	51
A. Cleaning and Sanitizing Procedures............................................................................	51
1. Cleaning Procedure...............................................................................................	52
2. Sanitizing Procedure - Following Cleaning Procedure...........................................	53
B. Maintenance................................................................................................................	53
C. Preparing the Icemaker for Long Storage....................................................................	54

I. Specifications

A. Icemaker

1. KM-501MAH (air-cooled)

AC SUPPLY VOLTAGE	115/60/1
AMPERAGE	13 A ( 5 Min. Freeze AT 104°F / WT 80°F)
MINIMUM CIRCUIT AMPACITY	20 A
MAXIMUM FUSE SIZE	20 A
APPROXIMATE ICE PRODUCTION	Ambient	WATER TEMP. (°F)
PER 24 HR.	Temp.(°F)	50		70		90
lbs./day ( kg/day )	70	*498 (226)		474 (215)		433 (197)
Reference without *marks	80	480 (218)		442 (201)		397 (180)
	90	474 (215)		*416 (189)		372 (169)
SHAPE OF ICE	100	463 (210)		406 (184)		332 (150)
	Crescent Cube
ICE PRODUCTION PER CYCLE	9.5 lbs. (4.3 kg) 480 pcs.
APPROXIMATE STORAGE CAPACITY	N/A
ELECTRIC & WATER CONSUMPTION	90/70°F			70/50°F
ELECTRIC W (kWH/100 lbs.)	1210(7.0)			1140(5.5)
WATER gal./24HR (gal./100 lbs.)	89(21.3)			245(49.1)
EXTERIOR DIMENSIONS (WxDxH)	22" x 27-3/8" x 30-5/16" (560 x 695 x 770 mm)
EXTERIOR FINISH	Stainless Steel, Galvanized Steel (Rear)
WEIGHT	Net 151 lbs. (69 kg), Shipping			175 lbs. (80 kg)
CONNECTIONS - ELECTRIC	Permanent - Connection
- WATER SUPPLY	Inlet	1/2" FPT
- DRAIN	Outlet	3/4" FPT
		3/8" OD Tube
CUBE CONTROL SYSTEM	Float Switch
HARVESTING CONTROL SYSTEM	Hot Gas and Water, Thermistor and Timer
ICE MAKING WATER CONTROL	Timer Controlled. Overflow Pipe
COOLING WATER CONTROL	N/A
BIN CONTROL SYSTEM	Thermostat
COMPRESSOR	Hermetic, Model AKA9455ZXA
CONDENSER	Air-Cooled , Fin and tube type
EVAPORATOR	Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL	Thermostatic Expansion Valve
REFRIGERANT CHARGE	R-404A, 1 lb. 10 oz. (735g)
DESIGN PRESSURE	High 467PSIG, Low 210PSIG
P.C. BOARD CIRCUIT PROTECTION	High Voltage Cut-out ( Internal )
COMPRESSOR PROTECTION	Auto-reset Overload Protector ( Internal )
REFRIGERANT CIRCUIT PROTECTION	Auto-reset High Pressure Control Switch
LOW WATER PROTECTION	Float Switch
ACCESSORIES -SUPPLIED	N/A
-REQUIRED	Ice Storage Bin
OPERATING CONDITIONS	VOLTAGE RANGE					104 - 127 V
	AMBIENT TEMP.					45 -100° F
	WATER SUPPLY TEMP.					45 - 90° F
	WATER SUPPLY PRESSURE					10 - 113 PSIG

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

2. KM-501MWH (water-cooled)

AC SUPPLY VOLTAGE	115/60/1
AMPERAGE	10 A ( 5 Min. Freeze AT 104°F / WT 80°F)
MINIMUM CIRCUIT AMPACITY	20 A
MAXIMUM FUSE SIZE	20 A
APPROXIMATE ICE PRODUCTION	Ambient	WATER TEMP. (°F)
PER 24 HR.	Temp.(°F)	50		70		90
lbs./day ( kg/day )	70	*498 (226)		495 (224)		465 (211)
Reference without *marks	80	496 (225)		491 (223)		447 (203)
	90	495 (224)		*488 (221)		449 (204)
SHAPE OF ICE	100	480 (218)		479 (217)		413 (187)
	Crescent Cube
ICE PRODUCTION PER CYCLE	9.5 lbs. (4.3 kg) 480 pcs.
APPROXIMATE STORAGE CAPACITY	N/A
ELECTRIC & WATER CONSUMPTION	90/70°F			70/50°F
ELECTRIC W (kWH/100 lbs.)	1080(5.3)			1070(5.2)
WATER gal./24HR (gal./100 lbs.)	101(20.8)			177(35.6)
WATER COOLED CONDENSER	670(137)			390(78)
gal./24HR (gal./100 lbs.)
EXTERIOR DIMENSIONS (WxDxH)	22" x 27-3/8" x 30-5/16" (560 x 695 x 770 mm)
EXTERIOR FINISH	Stainless Steel, Galvanized Steel (Rear)
WEIGHT	Net 151 lbs. (69 kg), Shipping			175 lbs. (80 kg)
CONNECTIONS - ELECTRIC	Permanent - Connection
- WATER SUPPLY	Inlet	1/2" FPT
- DRAIN	Outlet	3/4" FPT
		3/8" OD Tube
CUBE CONTROL SYSTEM	Float Switch
HARVESTING CONTROL SYSTEM	Hot Gas and Water, Thermistor and Timer
ICE MAKING WATER CONTROL	Timer Controlled. Overflow Pipe
COOLING WATER CONTROL	Pressure Regulator
BIN CONTROL SYSTEM	Thermostat
COMPRESSOR	Hermetic, Model AKA9455ZXA
CONDENSER	Water-cooled, Tube in tube type
EVAPORATOR	Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL	Thermostatic Expansion Valve
REFRIGERANT CHARGE	R-404A, 15 oz. (425g)
DESIGN PRESSURE	High 427PSIG, Low 210PSIG
P.C. BOARD CIRCUIT PROTECTION	High Voltage Cut-out ( Internal )
COMPRESSOR PROTECTION	Auto-reset Overload Protector ( Internal )
REFRIGERANT CIRCUIT PROTECTION	Auto-reset High Pressure Control Switch
LOW WATER PROTECTION	Float Switch
ACCESSORIES -SUPPLIED	N/A
-REQUIRED	Ice Storage Bin
OPERATING CONDITIONS	VOLTAGE RANGE					104 - 127 V
	AMBIENT TEMP.					45 -100° F
	WATER SUPPLY TEMP.					45 - 90° F
	WATER SUPPLY PRESSURE					10 - 113 PSIG

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

3. KM-501MRH (remote air-cooled)

AC SUPPLY VOLTAGE	115/60/1
AMPERAGE	15 A ( 5 Min. Freeze AT 104°F / WT 80°F)
MINIMUM CIRCUIT AMPACITY	20 A
MAXIMUM FUSE SIZE	20 A
APPROXIMATE ICE PRODUCTION	Ambient			WATER TEMP. (°F)
PER 24 HR.	Temp.(°F)			50	70		90
lbs./day ( kg/day )		70		*482 (219)	475 (215)		437 (198)
Reference without *marks		80		476 (216)	465 (211)		412 (187)
		90		475 (215)	*457 (207)		410 (186)
SHAPE OF ICE	100			458 (208)	446 (202)		367 (166)
	Crescent Cube
ICE PRODUCTION PER CYCLE	9.5 lbs. (4.3 kg ) 480 pcs.
APPROXIMATE STORAGE CAPACITY	N/A
ELECTRIC & WATER CONSUMPTION	90/70°F				70/50°F
ELECTRIC W (kWH/100 lbs.)	1260(6.6)				1220(6.1)
WATER gal./24HR (gal./100 lbs.)	90(19.6)				182(37.8)
EXTERIOR DIMENSIONS (WxDxH)	22" x 27-3/8" x 30-5/16" (560 x 695 x 770 mm)
EXTERIOR FINISH	Stainless Steel, Galvanized Steel (Rear)
WEIGHT	Net 151 lbs. ( 69 kg ), Shipping 175 lbs. ( 80 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 Water, Thermistor and Timer
ICE MAKING WATER CONTROL	Timer Controlled. Overflow Pipe
COOLING WATER CONTROL	N/A
BIN CONTROL SYSTEM	Thermostat
COMPRESSOR	Hermetic,		Model AKA9455ZXA
CONDENSER	Air-cooled Remote, Condenser Unit URC 6F
EVAPORATOR	Vertical type, Stainless Steel and Copper
REFRIGERANT CONTROL	Thermostatic Expansion Valve
	Condensing Pressure Regulator on URC-6F
REFRIGERANT CHARGE	R-404A,			4 lbs. 0 oz. ( 1800 g )
	( Icemaker 2 lbs. 1.5 oz. Cond. Unit 1 lb. 14 oz. )
DESIGN PRESSURE	High 467 PSIG, Low 230 PSIG
P.C. BOARD CIRCUIT PROTECTION	High Voltage Cut-out ( Internal )
COMPRESSOR PROTECTION	Auto-reset Overload Protector ( Internal )
REFRIGERANT CIRCUIT PROTECTION	Auto-reset High Pressure Control Switch
LOW WATER PROTECTION	Float Switch
ACCESSORIES -SUPPLIED	N/A
-REQUIRED	Ice Storage Bin, Remote Condenser Unit
OPERATING CONDITIONS	VOLTAGE RANGE						104 - 127 V
	AMBIENT TEMP.						45 -100° F
	WATER SUPPLY TEMP.						45 - 90° F
	WATER SUPPLY PRESSURE					10 - 113 PSIG

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

B.Condensing Unit

1.URC-6F

18-1/8" (460 mm.)

17-1/8" (435 mm.)

14-9/16" (370 mm.)

17-7/8" (454 mm.)

2-1/2" (63 mm.)

14-15/16" (380 mm.)

24" (610 mm.)

23-1/32"

(585 mm.)

19-11/16"	6/16" x 3/4" (10 mm. x 20 mm.)
(500 mm.)	4 x 2 (SLOTTED HOLES)

14-1/8" (358 mm.)

14-15/16" (380 mm.)

15-11/16" (398 mm.)

18-1/8"

(460 mm.)

20-15/32"

(520 mm.)

21-15/16"

(557 mm.)

7/8" DIA. HOLE (23 mm. DIA.)

6-5/16"

(160 mm.)

2-15/16"

(75 mm.)

SPECIFICATIONS

MODEL: URC-6F

EXTERIOR

DIMENSIONS (W x D x H)

REFRIGERANT CHARGE

WEIGHT

CONNECTIONS

REFRIGERANT

ELECTRICAL

CONDENSER

HEAD PRESSURE CONTROL

AMBIENT CONDITION

Galvanized Steel

21-15/16" x 15-11/16" x 17-7/8" (557 x 398 x 453.8 mm.)

R404A 1 lb. 2 oz. (505 g)

Net 61 lbs. (28 kg)

Shipping 68 lbs. (31 kg)

One Shot Couplings (Parker)

Permanent Connection

Air-cooled

Condensing Pressure Regulator

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

II. General Information

A.Construction

1.KM-501MAH (air-cooled)

Spray Tubes

Control Switch

Bin Control Thermostat

Expansion Valve

Compressor

Float Switch

Water Pump

Water Supply Inlet

Condenser

Hot Gas Valve

Fan Motor

Condenser

Drier

Control Box

10

2. KM-501MWH (water-cooled)

Spray Tubes

Water Supply Inlet

Control Switch
	Water Regulator
Bin Control Thermostat
Expansion Valve	Hot Gas Valve
Compressor
Float Switch	Drier
Water Pump	Control Box

11

3. KM-501MRH (remote air-cooled)

Spray Tubes

Water Supply Inlet

Control Switch
	Junction Box
Bin Control Thermostat
Expansion Valve	Receiver Tank
Compressor
Float Switch	Drier
Water Pump	Hot Gas Valve
	Line Valve
	Control Box

12

B. Sequence of Operation

The steps in the sequence are as outlined below. When power is supplied, a 5 second delay occurs at startup. Note that the order of the LEDs from the outer edge of the board is 1, 4, 3, 2.

1. One Minute Fill Cycle

LED 4 is on. WV opens and the fill period begins. After 1 minute, the board checks for a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV will remain energized

through additional 1 minute cycles until water enters the sump and F/S closes. This serves as a low water safety to protect the water pump.

2. Initial Harvest Cycle

LEDs 1, 4, and 2 are on. WV remains open, Comp and FMR energize, HGV opens, and harvest begins. As the evaporator warms, the thermistor located on the suction line checks for a 48°F (9°C) temperature. When 48°F (9°C) is reached, a 3.9 kΩ signal turns

the harvest over to the adjustable harvest timer which is factory set for normal conditions.

The timer has settings of 60, 90, 120, and 180 seconds (dip switch 1 & 2). The water valve is open during harvest for a maximum of 6 minutes or the length of harvest, whichever is shorter. When the harvest timer completes its count down, the harvest cycle is complete and the freeze cycle starts. The minimum total time allowed by the board for a complete harvest cycle is 2 minutes.

3. Freeze Cycle

LED 1 is on. Comp and FMR continue to run, PM and FMS energize, LLV opens, HGV and WV close and the freeze cycle starts. For the first 5 minutes the control board will not accept a signal from F/S. This 5 minute minimum freeze acts as a short cycle protection. At the end of 5 minutes, F/S assumes control. As ice builds on the evaporator the water level in the sump lowers. The freeze continues until F/S opens and terminates ice production.

4. Pump-Out Cycle

LEDs 1, 3, and 2 are on. Comp and FMR continue to run, HGV opens, LLV closes, and

FMS deenergizes. PM stops for 2 seconds and reverses, taking water from the bottom of the sump and forcing pressure against the check valve seat allowing water to go through the check valve and down the drain. At the same time water flows through the small tube to power flush the F/S. When the pump-out timer stops counting, the pump out is complete. Pump out always occurs on the 2nd harvest after startup. Then, depending on the control board setting, pump out occurs every cycle, or every 2nd, 5th or 10th cycle (dip switch 5 &

6).

5. Normal Harvest Cycle

LEDs 1, 4, and 2 are on. Comp and FMR continue to run, HGV remains open and WV opens. As the evaporator warms, the thermistor reaches 48°F (9°C). The control board then receives the thermistor's 3.9 kΩ signal and starts the harvest timer. The water valve is open during harvest for a maximum of 6 minutes or the length of harvest, whichever is shorter. When the harvest timer completes its count down, the harvest cycle is complete and the next freeze cycle starts. The unit continues to cycle through 3, 4 and 5 sequence until the bin control senses ice and shuts the unit down.

Legend: Comp–compressor; FMR–remote fan motor; FMS–self-contained fan motor;

F/S–float switch; HGV–hot gas valve; LLV–Liquid Line Valve; PM–pump motor; WV–inlet water valve

13

KM-501MAH, KM-501MWH, KM-501MRH Sequence Flow Chart and Component Operation

Cycle Steps

2. Harvest Cycle

3. Freeze Cycle

1. One Minute

• Maximum inlet water valve time: 6 minutes

• Minimum freeze time: 5 minutes

4. Pump-Out

Fill Cycle

• Maximum harvest time: 20 minutes

• Maximum freeze time: freeze timer setting

Cycle

			Thermistor in	1 to 3 minute timer	5 minute timer	F/S in
	Initial startup always		control	in control	in control	control
14	begins here		F/S closed		F/S closed
	"E" board will have	F/S Check		F/S Check
	5 second delay	WV Energized	Comp energized	Thermistor temp	Comp continues	Freeze cycle	Pump motor stops
		F/S open	HGV energized	reaches 48°F (9°C)	FMR continues	operation turned	for 2 sec. and then
			FMR energized	(3.9 kΩ or less)	HGV de-energized	over to F/S	reverses for 10/20 sec.
			WV continues	Harvest timer starts	WV de-energized		each 1, 2, 5, or 10 cycles.
					PM energized		Comp continues
				F/S open	FMS energized		FMR continues
				If F/S is open, compressor stops and cycle returns to 1 minute fill			HGV energized
							FMS de-energized

Legend:Comp - compressor	FMS - self-contained fan motor	HGV - hot gas valve	WV - inlet water valve
FMR - remote fan motor	F/S - float switch	PM - pump motor

C.Control Board

•A HOSHIZAKI exclusive solid-state control is employed in KM-501MAH, KM 501MWH and KM 501MRH Modular Crescent Cubers.

•All models are pretested and factory-adjusted.

CAUTION

1.Fragile, handle very carefully.

2.A control board contains integrated circuits, which are susceptible to failure due to static discharge. 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 and float switch. K4 is not connected.

5.Always replace the whole board assembly if it goes bad.

6.Do not short out power supply to test for voltage.

15

1. Control Board Layout

Control Products "E" Control Board

Alarm Reset Switch

Dip Switch

Backup Freeze

Timer LED

Backup Harvest

Timer LED

Alarm Buzzer

Power LED (lights when power is supplied to the board)

Relay LEDs (4) (indicate which relays are energized as listed below)

LED 2

Hot Gas Valve (HGV)

Self-Contained Fan

Motor (FMS) (FMS off when LED on)

LED 3

Pump Motor (PM) (on at pump out only)

LED 4

Water Valve (WV)

LED 1

Compressor (Comp) Remote Fan Motor (FMR)

Transformer

Connector

Output Test Switch

(used to test relays on board)

Connector K3 Harvest Control (thermistor)

Connector K4 Open

(not connected)

Microprocessor (board revision level indicated by last 2 digits on label)

Connector K5

Float Switch

Part Number

Connector K1

Pins #1 through #10

#1, 9 Magnetic Contactor #2 Hot Gas Valve

#3 Line Valve

Self-Contained Fan Motor (FMS) #4 Pump Motor (icemaking)

#5 Pump Motor (drain) #6 Water Valve

#7, 10 Power (line, bin control) #8 Open

Switch for "C" board and "ALPINE" board (service boards only)

	Control Board
Part Number	2A1410-01 (factory); 2A1410-02 (service)
Type	HOS-001A (Control Products - 10 Pin)

16

2. Features

a)Maximum Water Supply Period – 6 minutes

Inlet water valve opening, in the harvest cycle, is limited by the harvest timer. The water valve cannot remain open longer than the maximum period. The water valve can close in less than six minutes if the harvest cycle is completed.

b)Harvest Backup Timer and Freeze Timer

The harvest backup timer shuts down the icemaker if, for two cycles in a row, the harvest cycle takes more than 20 minutes to complete. The control board will signal this problem using 2 beeps every 3 seconds.

The freeze timer shuts down the icemaker if, for two cycles in a row, the freeze cycle takes longer than the time specified to complete. The control board will signal this problem using 3 beeps every 3 seconds. The time is factory set using dip switches 9 & 10.

The reset button on the control board must be pressed with power on to reset either of these safeties.

c)High Temperature Safety

The temperature of the suction line in the refrigeration circuit is limited by the high temperature safety. This protects the unit from excessively high temperatures. If the evaporator temperature rises above 127 ± 7°F (53 ± 4°C), the thermistor operates the safety. This shuts down the circuit and the icemaker automatically stops.

The control board will signal this problem using 1 beep every 3 seconds. The reset button on the control board must be pressed with power on to reset the safety.

d)Low Water Safety

If the pump motor is operated without water, the mechanical seal can fail. To prevent this type of failure, the control board checks the position of the float switch at the end of the initial one minute water fill cycle and at the end of each harvest cycle.

If the float switch is in the up position (electrical circuit closed), the control board changes to the ice making cycle. If the float switch is in the down position (electrical circuit open), the control board changes to additional one minute water fill cycles until water enters the sump and the float switch closes. When the float switch closes, the control board changes to the ice making cycle. The unit will not start without adequate water in the sump. This serves as a low water safety to protect the pump motor from mechanical seal failure.

For water-cooled model, if the water is shut off, the unit is protected by the high pressure switch.

e)High Voltage and Low Voltage Cut-outs

The maximum and minimum allowable supply voltages of this icemaker are limited by the high voltage and low voltage cut-outs.

If miswiring (especially on single phase 3 wire models) causes excessive voltage (147Vac

±5% or more) on the control board, the high voltage cut-out shuts down the circuit in 3 seconds and the icemaker automatically stops. The control board will signal this problem using 7 beeps every 3 seconds.

The icemaker also automatically stops in cases of insufficient voltage (92Vac ±5% or less). The control board will signal this problem using 6 beeps every 3 seconds. When the proper supply voltage is resumed, the icemaker automatically starts running again.

17