Mitsubishi Electric 800 Series Instruction Manual page 378

 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.
NOTE
• Note that a PM motor cannot be driven by the commercial power supply.
 Precautions for electronic bypass sequence function
• The response time of the inverter to the signals depends on the command source, NET or External. After the
communication with the inverter is established, the motor operation is performed according to the command via NET. The
commercial power supply operation with the motor is performed when the MRS signal turns ON before the communication
is established. It is recommended to turn the MRS signal ON after the communication is established. Example: the
response time of the inverter to the signals in the Network operation mode (power-ON). The command source is External
for the MRS signal and NET for the STF (STR) and CS signals.
Power supply
Communication status
MRS(External)
STF(NET)
CS(NET)
ON
ON
Until the communication with the inverter is established
From when the communication is established until the inverter receives a command
ON
ON
ON
Commercial
Inverter operation
power supply
operation
5. PARAMETERS
5.11 (A) Application parameters
3
4
5
5
5
6
7
8
9
10
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