Section 5 | Before Calling Service |
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Temperature is Too High or Low
QF400/QC700/QF800
The temperature sensor (thermistor) is mounted on the compressor discharge line. The temperature sensor provides input to the control board. The control board monitors the temperature anytime the compressor is energized.
If the thermistor detects 245°F or higher for 15 continuous seconds:
1.The ice machine will
2.The control board “Disch Temp” light will continue to flash twice then pause, to indicate the ice machine has shut off on high temperature.
3.The ice machine will remain off until the toggle switch is moved from ICE to OFF, and back to ICE.
or
Line voltage is interrupted and restored.
If the thermistor detects 155°F or less for 3 continuous minutes:
1.The control board ignores the low temperature limit for the first 30 minutes of compressor run time.
2.The ice machine will
3.After the
Temperature Sensor Checklist
4.After 30 minutes of compressor run time, the ice machine will check the discharge line temperature.
Discharge line temperature normal: The ice machine continues to make ice.
Discharge line temperature below 155°F after 30 minutes of run time:
The ice machine will start another
If the discharge line temperature drops below 155°F for 3 continuous minutes during 7 consecutive cycles the ice machine will start a SafeGuard Mode.
During the SafeGuard Mode the ”Disch Temp” light will continually flash to indicate a Safeguard Mode. The ice machine remains off until:
•The toggle switch is moved from ICE to OFF, then back to ICE.
•Line voltage is interrupted and restored.
INDICATOR LIGHT
Before 48 hours have elapsed:
After a Standby Mode has been initiated the Control Board “Disch Temp“ light will flash anytime the toggle switch is placed in the OFF position.
After 48 hours have elapsed:
The SafeGuard will be automatically erased from memory and the “Disch Temp” light will not flash.
Possible Problem List | Corrective Action List |
Thermistor is not properly insulated | Insulate thermistor. |
Thermistor loose | Secure thermistor to discharge line. |
Thermistor mounted in the wrong location | Position thermistor on discharge line 6 in. from compressor |
| discharge port. |
Thermistor defective | Refer to CHECK PROCEDURE under “Thermistor.” |
Flooding expansion valve | Replace expansion valve. |
Refrigerant overcharge or undercharge | Recover and weigh in nameplate charge. |
Low ambient temperature | Verify ambient temperature remains above 45°F (7.2°C). |
Defective compressor | Replace compressor. |
Insufficient or low water pressure | Verify water pressure is between 20 and 80 psig. |
Part Number 000002688 |
