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Maintenance
prevent injury. Keep hands, clothing and tools clear of the
electrical terminals and rotating components. Ensure that
the footing is stable at all times.
Table 1.
Troubleshooting
SYMPTOM
Chilled Water Valve Fails to Open
or Close
EC Fan(s) Fail to Start
Control is Erratic
System Short of Capacity
Electric Heater Inoperable
Hot water Heater
20
PROBABLE CAUSE
1.
Temperature set point too high/low.
2.
No control power to the chilled water valve.
3.
Actuator failed
1.
Power failure
2.
Motor starter protector (MSP) tripped
3.
Control transformer circuit breaker tripped
4.
EC fan's internal overheat protection
interrupted fan motor operation.
5.
Defective fan.
Wiring improperly connected or broken.
1.
Low chilled water flow.
2.
Supply water temperature too high.
3.
Reduced airflow.
4.
Dirty coil.
1.
Circuit breaker tripped.
2.
Temperature setpoint too low.
3.
Overheat switch open.
4.
Manual reset overheat safety switch tripped.
5.
Heater element burned out.
6.
Defective contactor.
1.
Low hot water flow.
2.
Hot water supply temperature too low.
3.
Temperature setpoint too low.
4.
Control power interrupted.
RECOMMENDATION
Adjust to correct temperature setting.
Check wiring diagram and rewire if required.
Replace actuator.
1. Check main power source voltage.
2. Check power input cable
Reset motor starter protector and check amperage of
motor. Compare to setting on the motor starter
protector and adjust to the correct FLA if necessary.
Check for short circuit or ground fault. If none, reset
circuit breaker.
Determine the cause of the interruption and correct.
Possible causes are:
1. Blocked rotor.
2. Low supply voltage > 5 seconds.
3. Loss of phase > 5 seconds.
After causes 1, 2, and 3 are corrected, the motor will
automatically reset.
4. Over-temperature of electronics.
5. Over-temperature of motor.
After causes 4 and 5 are corrected, the fan(s) must be
manually reset by turning off power for 20 seconds.
Repair or replace,
Check wiring against schematic diagram.
Check for leaks.
Check chilled water supply.
Check filters, dampers.
Clear coil fins of debris.
Check for short circuit; reset circuit breaker.
Increase temperature setpoint.
Insufficient air flow across heater elements. Correct
or replace as needed.
Reset manual overheat safety switch (see item
immediately above).
Check continuity with an ohm meter. Replace heater
element.
Repair or replace.
Check hot water flow at supply source. Inspect piping
for leaks or obstructions.
Check hot water supply.
Increase temperature setpoint.
Check for loose or broken wires.
AH-SVX010C-EN
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