Hitachi SJ Series, User Manual

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12-14-7
Chapter 12 Inverter Function
When instantaneous power failure/under-voltage
occurs [bb-24]=02
Ex. 1: Power recovery within Allowable
instantaneous power failure time [bb-25]
Parameter
• If a power failure has occurred so that the power
to the inverter's control power supply terminals
(R0,T0) is lost, and then the inverter is restarted, it
is considered as power-on and the inverter will
operate in accordance with the restart after reset
[bb-41].
• Even if the power to control power supply
terminals (R0, T0) is lost, it will take time until the
internal power supply is completely lost.
• Trip after instantaneous power
failure/under-voltage can be switched between
"enabled" and "disabled" by using [bb-27]
Selection of instantaneous power
failure/under-voltage trip during stopping. This will
prevent the occurrence of an error during stopping.
If the error is prevented, the output terminal [AL]
will not turn on.
t0: Instantaneous power failure time
t1: Allowable instantaneous power failure time [bb-25]
t2: Retry wait time [bb-26]
Ex. 2: Power recovery after Allowable instantaneous
power failure time [bb-25]
• In a system where the power to control power
supply terminals (R0, T0) gradually decreases, it
is possible to cause a trip when Allowable
instantaneous power failure time has elapsed.
• To make the power to control power supply
terminals (R0, T0) last as much as possible by the
inverter alone when an instantaneous power
failure occurs, remove the J51 connector cables
from terminals R0 and T0, connect the main circuit
terminals P and R0 to each other, and connect the
main terminals N and T0 to each other. Use 0.75
mm
2
or heavier wires for the connections.
Item Parameter Data Description
Selection of instantaneous power
failure/under-voltage retry [bb-24] 02 Performs frequency pull-in restart.
Allowable instantaneous power
failure time [bb-25] 0.3~25.0(s) Restarts the motor if it is within the
allowable time.
Retry wait time after instantaneous
power failure/under-voltage [bb-26] 0.3~100.0(s) Sets the wait time after the operation
command.
!
t0
t2
t1
Free-running
Power
supply
Inverter output
Motor speed
[bb-42]
Restarting with frequency pull-in
t1
T0
Free-running
Power
supply
Inverter output
Motor speed
[bb-42]