Electronic Bypass Function; Electronic Bypass Sequence Function - Mitsubishi Electric FR-F800 Instruction Manual

5.11.1

Electronic bypass function

The inverter contains complicated sequence circuits for switching between the commercial power supply operation and
inverter operation. Therefore, interlock operation of the magnetic contactor for switching can be easily performed by
simply inputting start, stop, and automatic switching selection signals.
Pr. Name
57
Restart coasting time
A702
58
Restart cushion time
A703
135 Electronic bypass
A000 sequence selection
136 MC switchover interlock
A001 time
137
Start waiting time
A002
138
Bypass selection at a fault
A003
Automatic switchover
139
frequency from inverter to
A004
bypass operation
Automatic switchover
159 frequency range from
A005 bypass to inverter
operation

The coasting time when Pr.57 = "0" is as shown below. (When Pr.162 Automatic restart after instantaneous power failure selection is set to
the initial value.)
FR-F820-00077(1.5K) or lower and FR-F840-00038(1.5K) or lower: 0.5 s
FR-F820-00105(2.2K) to FR-F820-00340(7.5K) and FR-F840-00052(2.2K) to FR-F840-00170(7.5K): 1 s
FR-F820-00490(11K) to FR-F820-02330(55K) and FR-F840-00250(11K) to FR-F840-01160(55K): 3.0 s
FR-F820-03160(75K) or higher and FR-F840-01800(75K) or higher: 5.0 s
Electronic bypass sequence function
• When operating the motor at 60 Hz (or 50 Hz), the motor can be more efficiently operated with a commercial power supply.
In addition, if the motor cannot be stopped for a long period of time even for an inverter maintenance and inspection, it is
recommended that a commercial power supply circuit be installed.
• When switching between inverter operation and commercial power supply operation, commercial power supply may be
accidentally applied to the output side of the inverter. To avoid such situation, provide an interlock where the magnetic
contactor at the commercial power supply side turns ON at turn OFF of the magnetic contactor at the inverter output side.
The inverter's electronic bypass sequence that outputs timing signals for the magnetic contactors can act as a complicated
interlock between the commercial power supply operation and the inverter operation.
Initial Setting
value range
0 Coasting time differs according to the inverter capacity.
Set the waiting time for the inverter to perform a restart at
9999 0.1 to 30 s
power restoration after an instantaneous power failure.
9999 No restart
1 s 0 to 60 s Set the voltage cushion time for restart.
0 Without electronic bypass sequence
0
1 With electronic bypass sequence
1 s 0 to 100 s Set the operation interlock time for MC2 and MC3.
Set a time period that is a little longer than the time period
0.5 s 0 to 100 s from the ON signal input to the actual pick-up operation of
MC3 (0.3 to 0.5 s).
0 Inverter output stop (motor coasting) at inverter failure
Automatic switchover to commercial power supply operation
0 at inverter failure. (Switchover is not possible when an
1
external thermal relay (E.OHT) or CPU fault (E.CPU) is
occurring.)
Set the frequency where the inverter operation is switched to
commercial power supply operation.
The inverter operation is performed from a start to Pr.139
0 to 60 Hz
setting, then it switches automatically to the commercial
9999
power supply operation when the output frequency is equal
to or above Pr.139.
9999 Without automatic switchover
Set the frequency where the commercial power supply
operation, which has been switched from the inverter
operation with Pr.139, switches back to inverter operation.
When the frequency command becomes less than (Pr.139 -
0 to 10 Hz
Pr.159), the motor switches automatically to inverter
operation and operates at the frequency of the frequency
command. Turning OFF the inverter start command (STF/
9999
STR) also switches the operation to the inverter operation.
To switch the commercial power supply operation, which has
been switched from the inverter operation with Pr.139, to the
9999 inverter operation again, the inverter start command (STF/
STR) is turned OFF. The operation switches to the inverter
operation, and the motor decelerates to a stop.
(A) Application parameters
V/F V/F V/F Magnetic flux Magnetic flux Magnetic flux
Description
PARAMETERS

5
GROUP
A
363