Analysis On Common Faults - Hitachi S1 Series Basic Manual

S1 series standard inverter
7.5.2 Other state
Displayed code
PoFF
Note: After set the RO terminal function as function 5 (inverter fault), it will send the signal to the
contactor to cut off the input power when inverter reports ETH (ground short circuit fault) or other
faults.

7.6 Analysis on common faults

7.6.1 Motor fails to work
Running
properly
Normal
Whether it runs
No
properly after the
parameters are
reset?
Exception occurs
Normal
Whether the
Running
communication wiring
properly
is performed properly?
State type
System power
failure
Rectify the fault
Yes
based on the
fault inforamtion
Communication
Whether communication
parameters are properly set?
Yes
normal
Running
properly
Exception occurs
Motor fault
Possible cause
The system is powered off or
the bus voltage is too low.
Motor fails to work
Whether the POWER
indicator is on?
Whether the keypad
displays information?
Yes
Whether fault information
is displayed?
No
Identify the channel of
running commands
Keypad
Press RUN to run
Exception occurs
Whether the speed
command is set
properly?
Yes
Exception occurs
Check the voltage of
UVW with a multimeter
Normal
Whether the motor is
properly wired?
Yes
No
Whether the load is too
heavy?
-161-
Check the grid
conditions.
Whether the air switch
No
and EM contactor on the
input side are closed?
Yes
Check the voltage
of RST with a
multimeter
Exception occurs
Terminal
Check the voltage
of the grid
Check whether the input terminal
is in the correct state
Yes
No
Whether it runs properly after the
speed command is properly set?
Inverter fault
No
Wire the motor
properly
Reduce the load if
Yes
the motor is locked
due to heavy loads
Solution
No
Close the air
contactor
Normal
Inverter fault
Running
properly
Normal
Whether it runs
No
properly after the
terminal is closed?
Exception occurs
Normal
Normal
running