Instantaneous Power Failure/Under-Voltage Signal - Hitachi SJ300 Series Instruction Manual

Instantaneous
An instantaneous power failure (complete loss) or under-voltage condition (partial loss) of
inverter input voltage can occur without warning. SJ300 Series inverters can be configured to
Power Failure /
respond to these conditions in different ways. You can select whether the inverter trips or retries
Under-voltage
(restart attempt) when an instantaneous power failure or under-voltage condition occurs. You
Signal
can select the retry function with parameter B001.
When enabled, the Retry Function operates in the following ways:
• Under-voltage conditions – When an instantaneous power failure or under-voltage condi-
• Over-current/voltage conditions – When retry function is selected and an over-current or
tion occurs, the inverter will attempt to restart up to 16 times. A trip condition will occur on
the 17th attempt, which must be cleared with the Stop/Reset key.
an over-voltage condition occurs, a restart is attempted 3 times. A trip will occur on the 4th
failed restart attempt. Use parameter B004 to select the trip and alarm response to instanta-
neous power failure and under-voltage conditions. The following table shows the related
parameters to these power fault conditions, and timing diagrams are on the next page.
Code Function
B001 Selection of
automatic restart
mode
B002 Allowable under-
voltage power failure
time
B003 Retry wait time
before motor restart
B004 Instantaneous power
failure / voltage trip
alarm enable
B005 Number of restarts
on power failure /
under-voltage trip
events
B007 Restart frequency
threshold
Data or Range
00 Alarm output after trip, automatic
restart disabled
01 Restart at 0 Hz
02 Retry with frequency matching to
present motor speed
03 Retry with frequency matching
followed by deceleration to stop—
then trip alarm
0.3 to 1.0 sec. The amount of time a power input
under-voltage can occur without
tripping the power failure alarm. If
under-voltage exists longer than this
time, the inverter trips, even if the
restart mode is selected. If it exists
less than this time retry will be
attempted.
0.3 to 100 sec. Time delay after a trip condition goes
away before the inverter restarts the
motor
00 Disable
01 Enable
02 Disable during stop and ramp to stop
00 Restart up to 16 times on instanta-
neous power failure or under-voltage
01 Always restart on instantaneous
power failure or an under-voltage
condition
0.00 to 400.0 Hz When frequency of the motor is less
than this value, the inverter will
restart at 0 Hz
4–51
SJ300 Inverter
Description