6-22
Possible Causes
What to Check and Suggested Measures
(6) A high intensity noise
was given to the
inverter.
Check if appropriate noise control measures have been
implemented (e.g., correct grounding and routing of control and
main circuit wires).
Î
Improve noise control.
Î
Improve noise reduction measures on the host side.
Î
Replace the RS-485 relay converter with a recommended
insulated converter.
(7) The RS-485
communications card
malfunctioned.
Î
Replace the RS-485 communications card (option).
[ 20 ]
erf
Data saving error during undervoltage
Problem
The inverter failed to save data such as the frequency commands, PID commands,
timer value for the timer operation (which are specified through the keypad) or the
output frequencies modified by the
UP
/
DOWN
terminal commands when the power
was switched OFF.
Possible Causes
What to Check and Suggested Measures
(1) The voltage fed to the
control PCB dropped
suddenly while data was
being saved when the
power was turned OFF,
because the DC link bus
was rapidly discharged.
Check how long it takes for the DC link bus voltage to drop to the
preset voltage when power is turned OFF.
Î
Remove whatever is causing the rapid discharge of the DC link
bus electricity. After pressing the
key and releasing the
alarm, return the data of the relevant function codes (such as the
frequency commands, PID commands, timer value for the timer
driven operation (specified through the keypad) or the output
frequencies modified by the
UP
/
DOWN
terminal commands
when the power was switched OFF) back to the original values
and then restart the operation.
(2) A high intensity noise
affected the operation of
the inverter while data
was being saved when
the power was turned
OFF.
Check if appropriate noise control measures have been
implemented (e.g., correct grounding and routing of control and
main circuit wires).
Î
Improve noise control. After pressing the
key and releasing
the alarm, return the data of the relevant function codes (such as
the frequency commands, PID commands, timer value for the
timer driven operation (specified through the keypad) or the
output frequencies modified by the
UP
/
DOWN
terminal
commands when the power was switched OFF) back to the
original values and then restart the operation.
(3) The control circuit failed.
Check if
erf
occurs each time power is switched ON.
Î
The control PCB (on which the CPU is mounted) is defective.
Contact your Fuji Electric representative.