III. Controls and Adjustments. Hoshizaki KM-1100MAJ50

III. Controls and Adjustments

• A Hoshizaki exclusive control board is employed in KM series appliances.

• All models are pretested and factory adjusted.

• For a control board check procedure, see "II.C. Control Board Check."

NOTICE

• Fragile, handle very carefully.

• The control board contains integrated circuits, which are susceptible to failure due to static discharge. It is especially important to touch the metal part of the icemaker when handling or replacing the control board.

• Do not touch the electronic devices on the control board or the back of the control board.

• Do not change wiring and connections. Do not misconnect K3 WHITE, K4 RED, and K5 BLACK, because the same connector is used for the thermistor, jumper, and float switch.

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

• Always replace the whole control board assembly if it goes bad.

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A. Control Board Layout

1. "J" Control Board

"J" Control Board

• Bin Control Switch Closed LED (green)

(on continuously in thermostatic bin control application)

• Bin Control Switch Open LED (yellow)

(mechanical bin control application only)

• "ALARM RESET" Button • Part Number • Alarm Buzzer • S4 Dip Switch • "OUTPUT TEST" Button

(used to test relays on control board)

• K3 (white) Connector

Thermistor (harvest control and high temperature safety)

• POWER OK LED (red)

(lights when 10.5VAC is supplied to K2 connector)

• Relay LEDs

(4) (indicate which relays are energized and which K1 connector pins are energized

• LED 2 (X2 Relay)

LED 2 on: K1 Connector Pin #2 LED 2 off: K1 Connector Pin #3

• LED 3 (X3 Relay)

LED 3 on: K1 Connector Pin #5 LED 3 off: K1 Connector Pin #4 (energized in freeze)

• LED 4 (X4 Relay)

K1 Connector Pin #6

• LED 1 (X1 Relay)

K1 Connector Pin #1, #9

• K4 (red) Connector

K4 Jumper (thermostatic bin control application)

• S5 Dip Switch • K5 (black) Connector

Float Switch (water level)

Label

(control board revision level indicated on label on side of relay)

• K1 Connector

Pins #1 through #10 #1, 9 Compressor Relay Fan Motor #2 Hot Gas Valve #3 Liquid Line Valve #4 Pump Motor (icemaking) #5 Pump Motor (harvest pump timer and pump-out) #6 Inlet Water Valve #7, 10 Component Power Supply #8 Open

• K2 Connector

Control Transformer (10.5VAC)

"J" Control Board

Part Number 2A7664-04 28

B. LED Lights and Audible Alarm Safeties

Beep occurs and red "POWER OK" LED turns on when control switch is moved to "ICE" position.

Sequence

Green LEDs 1 through 4 turn on and sequence from initial startup as listed in the table below. Order of green LEDs from the outer edge of control board is 1, 4, 3, 2.

Sequence Step

1-Minute Fill Cycle Harvest Cycle Harvest Pump Time (harvest assist) Freeze Cycle

LED

4 1, 4, 2 1, 3, 2

Energized Components

WV Comp, FM, HGV, WV Comp, FM, HGV, PM

Time LEDs are On Min.

Max.

1 minute 20 minutes 0 seconds 50 seconds Anti-Slush Control 1 1, 3 Comp, FM, PM, LLV Comp, FM, LLV 5 minutes freeze timer setting If S5 dip switch 5 on, PM off 10 sec. when thermistor at 36°F (2.2°C) 10 seconds 20 seconds Pump-Out Cycle 1, 4 † , 3, 2 Comp, FM, HGV, PM, WV † , DV *FM energized if on K1 Connector Pin #9; † pump-out timer setting

Alarms Type

1 Beep

Alarm

High Evaporator Temp. (temperature > 127°F) (53°C)

Notes

Check for harvest problem (stuck HGV or relay), hot water entering unit, stuck HM, or shorted thermistor. 2 Beep 3 Beep Harvest Backup Timer (harvest > 20 min. for two cycles in a row) Freeze Timer (freeze > freeze timer setting for two cycles in a row) Check thermistor (open), HGV not opening, TXV or LLV leaking by, low charge, inefficient Comp.

Check FS stuck closed (up), WV leaking by, HGV leaking by, PM not pumping, TXV defective, LLV not opening, low charge, or inefficient Comp.

To reset above safeties, press "ALARM RESET" button with power supply on.

6 7 Low Voltage (92Vac±5% or less) High Voltage (147Vac±5% or more) Red LED turns off if voltage protection operates. Control voltage safeties automatically reset when voltage is corrected.

Legend:

CB

–control board;

Comp

–compressor;

FM

–fan motor;

FS

–float switch;

HGV

–hot gas valve;

HM

–headmaster (C.P.R.);

LLV

–liquid line valve;

PM

–pump motor;

TXV

–thermostatic expansion valve;

WV

–inlet water valve 29

C. Settings and Adjustments

NOTICE

Dip switches are factory set. Failure to maintain factory settings may adversely affect performance and warranty coverage. For more information, contact your Hoshizaki Service Center.

1. Default Dip Switch Settings

The dip switches are factory-adjusted to the following positions:

S4 Dip Switch No.

KM-1100MAJ50

1 2 3 4 5 6 7 8 9 10

OFF OFF OFF OFF OFF OFF ON OFF OFF OFF

S5 Dip Switch (Do Not Adjust) "J" Control Board Dip Switch No.

1 2 3 4

KM-1100MAJ50

5

OFF OFF OFF OFF ON

S4 Dip Switch "J" Control Boards

Freeze Timer (9 & 10) Factory Use (8) Harvest Pump Time (Harvest Assist) (7) (Do Not Adjust) Harvest Pump Time (Harvest Assist Duration) (6) (Do Not Adjust) Pump-Out Frequency Control (5) Pump-Out Time/Harvest Time During Pump-Out (3 & 4) Harvest Timer (1 & 2)

S5 Dip Switch "J" Control Board Only

Do Not Adjust Anti-Slush (5) Minimum Harvest Time (4) Refill Counter (2 and 3) Float Switch Selector (1) 30

2. Harvest Timer (S4 dip switch 1 & 2)

The harvest timer starts counting when the thermistor reaches 48°F (9°C) at the evaporator outlet and the control board reads 3.9 kΩ from the thermistor. The harvest timer is factory set, and generally no adjustment is required. However, a setting longer than the factory setting may be advised in cases where the drain provided at harvest needs to be prolonged for extra cleaning. Before changing this setting, contact Hoshizaki Technical Support at 1-800-233-1940 for recommendations. Keep in mind that setting the harvest timer to a longer setting decreases 24-hour production.

Note that the pump-out timer (S4 dip switch 3 & 4) acts in place of the harvest timer during cycles with a pump out. For details, see "III.C.3. Pump-Out Timer (S4 dip switch 3 & 4)." Note: On models with a pump-out every cycle, the harvest timer is only relevant during the initial harvest cycle since a pump out occurs every cycle thereafter.

S4 Dip Switch Setting No. 1 No. 2

OFF OFF ON OFF ON OFF ON ON

Time (sec.)

60 90 120 180

3. Pump-Out Timer/Harvest Time During Pump-Out (S4 dip switch 3 & 4)

NOTICE

• On models with harvest pump timer, do not adjust 3 off and 4 on. Pump does not run in pump-out rotation in this setting.

When a pump-out is called for, the pump motor stops for 2 sec., then energizes in the reverse direction, taking water from the bottom of the water tank and forcing pressure against the check valve seat allowing water to go through the check valve and down the drain. At the same time, water flows through the small tube to power flush the float switch. The pump motor drains the water tank for the time determined by the pump-out timer. The pump-out timer also acts in place of the harvest timer during cycles with a pump-out. The pump-out timer is factory set, and generally no adjustment is required. However, where water quality is bad and the icemaker needs a longer pump-out time, the pump-out timer can be adjusted. The pump-out timer control can be set to pump-out for 10 or 20 sec.

S4 Dip Switch Setting T1 No. 3

OFF ON OFF ON

No. 4

OFF OFF ON ON 10 10 10 20 T1: Time to drain the water tank T2: Harvest timer at pump out

Time (sec.) T2 S5-4 OFF S5-4 ON

150 100 180 120 180 130 70 180 31

Inlet Water Valve S5-4 OFF S5-4 ON

Closed Closed Closed Open Closed Closed Closed Closed

4. Pump-Out Frequency Control (S4 dip switch 5)

The pump-out frequency control is factory set to drain the water tank every 10 cycles.

Generally no adjustment is required. However, where water quality is bad and the icemaker needs a pump-out more often, the pump-out frequency can be adjusted. The pump-out frequency control can be set to have a pump-out occur every cycle, or every 10 cycles.

The first pump-out is dependent on S4 dip switch 5. See the table below.

S4 Dip Switch Setting No. 5

OFF ON

Pump-Out Frequency

Every 10 cycles Every cycle

1st Pump-Out

After 11th freeze cycle After 2nd freeze cycle

5. Harvest Pump Time (Harvest Assist Duration) (S4 dip switch 6)

NOTICE

Factory set for proper operation. Do not adjust. Adjustment outside of the factory default setting may result in damage to the appliance. Harvest pump time (harvest assist duration) is only active when S4 dip switch 7 is in the "ON" position. In the factory default position, the harvest pump time (harvest assist duration) starts with 50 sec. left to go in harvest cycle (S4 dip switch 6) and after the thermistor reaches 48°F (9°C) at the evaporator outlet and the control board reads 3.9 kΩ from the thermistor. The harvest pump time (harvest assist duration) is factory set, and no adjustment is required.

S4 Dip Switch Setting No. 6

OFF ON

Harvest Pump Time (Harvest Assist) S5-4 OFF S5-4 ON

50 sec.

25 sec.

25 sec.

15 sec.

32

6. Harvest Pump Time (Harvest Assist) (S4 dip switch 7)

NOTICE

Factory set for proper operation. Do not adjust. Adjustment outside of the factory default setting may result in damage to the appliance. a) Harvest Pump Time (Harvest Assist) Depending on S4 dip switch 7 setting, the pump motor either stays off or is energized during the last seconds of the harvest cycle. When the pump motor is energized (S4 dip switch 7 on), water circulates over the evaporator. The harvest water valve is open during harvest for a maximum of 6 minutes or the length of harvest minus the harvest pump time value (S4 dip switch 6), whichever is shorter. When S4 dip switch 7 is in the on position and harvest begins, X11 and X10 relays energize. A latching circuit is created through the X11 and X10 relays. For further details, see "VIII.B. Wiring Diagrams." In the factory default position, 50 sec. before harvest termination, LED 4 turns off, inlet water valve and X11 relay de-energize. X10 relay remains energized through the latching circuit. Next, LED 3 turns on and control board K1 connector pin #5 (DBU wire) energizes, energizing the pump motor for the last seconds of harvest. Harvest pump time adjusted by S4 dip switch 1 & 2 and S5 dip switch 4 settings. Contact Technical Support before adjusted these settings.

S4 Dip Switch Setting Harvest Pump Time No. 7 (Harvest Assist)

OFF ON Disabled Enabled

7. Factory Use (S4 dip switch 8)

Factory set for proper operation. Do not adjust. This must be left in the factory default position.

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8. Freeze Timer (S4 dip switch 9 & 10)

NOTICE

Adjust to proper specification, or the icemaker may not operate correctly.

The freeze timer setting determines the maximum allowed freeze time to prevent possible freeze-up issues. Upon termination of the freeze timer, the control board initiates the harvest cycle or pump-out cycle. After 2 consecutive freeze timer terminations, the control board shuts down the icemaker. In this case, see "II.H.3. Low Ice Production" for possible solutions. The freeze timer is factory set and no adjustment is required. Before changing this setting, contact Hoshizaki Technical Support at 1-800-233-1940 for recommendations.

S4 Dip Switch Setting No. 9 No. 10

OFF OFF OFF ON ON ON OFF ON

Time (min.)

60 50 70 75

9. Float Switch Selector (S5 dip switch 1)

NOTICE

Do not adjust. This must be left in the factory default position or the icemaker will not operate correctly.

This dip switch setting allows use of this control board in single and dual float switch models. This model uses a single float switch style.

S5 Dip Switch Setting Top or Bottom Float Switch No. 1 Control

OFF Bottom Float Switch Enabled ON Top Float Switch Enabled

10. Refill Counter (S5 dip switch 2 and 3)

NOTICE

Do not adjust. These must be left in the factory default position or the icemaker will not operate correctly.

S5 Dip Switch Setting No. 2 No. 3

OFF OFF OFF ON ON ON OFF ON

Refill Counter

0 1 refill 9 refills 10 refills 34

11. Minimum Harvest Time (S5 dip switch 4)

NOTICE

Factory set for proper operation. Do not adjust. Adjustment outside the factory default setting may result in damage to the appliance.

S5 Dip Switch Setting No. 4

OFF ON

Minimum Harvest Timer

120 sec.

70 sec.

12. Anti-Slush (S5 dip switch 5)

NOTICE

Factory set for proper operation. Do not adjust. Adjustment outside the factory default setting may result in damage to the appliance.

This dip switch setting provides anti-slush control during the freeze cycle. When the evaporator temperature reaches 36°F (2.2°C) the control board reads a 5.8kΩ signal from the thermistor and de-energizes the water pump for 10 sec. to melt ice slush and prevent ice slush from blocking the water supply tubing, causing irregular freeze patterns.

S5 Dip Switch Setting No. 5

OFF ON

Anti-Slush

Disabled Enabled 35