Envicool EMW90HDNC1U - Page 45

User Manual
7 Fault Management
EMW90HDNC1U Air-cooled Chiller
43
Alarm Name
Generation
Condition
Possible Causes Processing Method
Superheat
Protection
of the system is lower
than the alarm setting
value
Excessive refrigerant.
Recover a small amount of
refrigerant.
The electronic expansion
valve is faulty and the
opening is too large.
Replace the electronic
expansion valve.
Inaccurate monitoring due
to faulty suction
temperature sensor or
low pressure sensor.
Replace the suction
temperature sensor or low
pressure sensor.
Freq Inverter
Over Voltage
Compressor inverter
voltage is higher than
overvoltage alarm
point.
Input voltage is on the
high side.
Adjust the voltage to the normal
range.
The
acceleration/deceleration/
constant speed
overvoltage is caused by
external force dragging
the motor.
Cancel external power or install
braking resistor.
Acceleration overvoltage
is caused by short
acceleration time.
Increase the acceleration time.
Shorter deceleration time
leads to deceleration
overvoltage.
Increase deceleration time.
Acceleration/deceleration
overvoltage caused by no
additional braking
resistor.
Add braking resistor.
Freq Inverter
Under
Voltage
Compressor inverter
voltage is lower than
undervoltage alarm
point.
Instantaneous power
failure.
The alarm will be automatically
released after fault recovery.
The input terminal voltage
of the frequency
converter is not within the
specification
requirements.
Adjust the voltage to the normal
range.
Abnormal bus voltage.
Replace the frequency
converter.
Rectifier bridge and buffer
resistance are abnormal.
Replace the frequency
converter.
Abnormal driving board.
Replace the frequency
converter.
Abnormal control panel.
Replace the frequency
converter.