SI21 Solar Pump VFD Manual
12
Chapter 4 Fault Diagnosis and Solution
This chapter describes the VFD fault, alerts, and operation of the failure on the VFD, the display information
on VFD and countermeasures.
Keypad
display
Fault
code
Fault type
Possibility reason
Troubleshooting
E.LU2
Under
voltage at
runs
●Power voltage too low
●DC main contactor don’t
close
●Check input power to solve
●Ask support
E.oU1
Over voltage
at
acceleration
●Power voltage fluctuation
over limit
●Too start rotating motor
●Check power grid
●Restart until motor is stop
completely, or set [F1.00] set for
1 or 2
E.oU2
Over voltage
during
deceleration
●Deceleration time too
small
●The driving load too heavy
●Power voltage fluctuation
over limit
●Prolong deceleration time
●Reduce the load, or select
bigger capacitor drive, or connect
braking unit
●Check input power
E.oU3
Overvoltage
at
constant
speed
●The input voltage is too
high.
●An external force drives
the motor during
deceleration
●Adjust the voltage to
normal range.
●Cancel the external force or
install the braking resistor.
E.oU4
Over voltage
at stop
●Voltage fluctuate above
limit
●Check the input voltage
E.oC1
Over current
during
acceleration
●Acceleration time is too
short
●To start rotating motor
●V/F setting not correct or
torque boost setting too big
●Solar drive capacitor is too
small
●Prolong acceleration time
●Restart motor when it on still,
or set F1.00 for 1 or 2.
●Reset V/f curve or torque boost
setting
E.oC2
Over current
during
deceleration
●The output circuit is
grounded or short circuited.
●Motor auto-tuning is not
performed.
●The acceleration time is
too short.
●Manual torque boost or
V/F curve is not appropriate.
●The voltage is too low.
●The startup operation is
●Eliminate external faults.
●Perform the motor auto tuning.
●Increase the acceleration time.
●Adjust the manual torque boost
or V/F curve.
●Adjust the voltage to
normal range.
●Select rotational speed tracking
restart or start the motor after it
stops.
