Hoshizaki KM-1301SRH-E Thermistor Check, Adjustment of Water Regulating Valve water-cooled model

E. Thermistor Check

To check thermistor resistance, follow the steps below.

1)Turn off the power supply.

2)Remove the front panel, then move the control switch to the "OFF" position.

3)Remove the control box cover.

4)Remove the thermistor.

5)Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3 minutes.

6)Disconnect the white thermistor connector from the control board WHITE K3 connector and check the resistance between thermistor leads. Normal reading is within 4.7 to

6.2 kΩ. If outside the normal reading, replace the thermistor. See "V.B. Important Notes for Component Replacement." If inside the normal reading, continue to the next step.

7)Replace the thermistor in its correct position. See "V.B. Important Notes for Component Replacement."

8)Reconnect the white thermistor connector to the control board WHITE K3 connector.

9)Replace the control box cover in its correct position, then turn on the power supply.

10)Move the control switch to the "ICE" position.

11)Once the harvest cycle starts, begin timing the harvest cycle.

12)The harvest timer should terminate and end the harvest cycle within 2 to 3 minutes. If the harvest timer does not terminate and end the harvest cycle, the harvest timer is bad and the control board should be replaced.

F. Adjustment of Water Regulating Valve (water-cooled model)

The water regulating valve (also called "water regulator") is factory set, and generally no adjustment is required. However, when necessary, adjust the water regulator using the following procedures.

1)Prepare a thermometer to check the condenser drain temperature. Attach a pressure gauge to the high-side line of the system.

2)Five minutes after a freeze cycle starts, confirm that the thermometer reads 104°F to 115°F (40°C to 46°C). If it does not, use a flat blade screwdriver to rotate the adjustment screw on the water‑regulating valve until the temperature is in the proper range (rotate counterclockwise to raise the temperature or clockwise to lower the temperature). See Fig. 5. Next, check that the reference pressure is in the range indicated in the Head Pressure table in the Performance Data section. If it is not in the proper range, verify the refrigerant charge.

Adjustment Screw

CCW – Higher

CW – Lower

Top View

Fig. 5

3) Check that the condenser drain temperature is stable.

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