Mitsubishi Electric FATEC FR-A800 Manual page 106

7
REVIEW OF INSTALLATION ENVIRONMENT
Power failure time deceleration-to-stop function
Usually, when a power failure occurs, the motor starts coasting. However, if the power failure
time deceleration-to-stop function is used, the motor can be decelerated in a relatively short
time by using the regenerative power. Even though the start signal is ON, it does not restart
at a power restoration. The mode in which the motor re-accelerates at a power restoration
during deceleration at occurrence of power failure can be selected as well.
Continuous operation function at instantaneous power failure
When an instantaneous power failure is detected, the operation is continued by using the
regenerative power generated by decelerating the motor. After the power restoration, the
motor is accelerated until it reaches the command frequency and continues to operate.
When the load inertia is small, a trip may occur due to an undervoltage since the
regenerative power from the motor is not provided.
In this case, use the automatic restart after instantaneous power failure.
7.1 Power supply of inverter (harmonics and instantaneous power failure)
Power
supply
During deceleration at
occurrence of power failure
During stop at
occurrence
of power failure
STF
Power supply
Instantaneous power failure
During deceleration
at occurrence of
power failure
Time
Re-acceleration
Time
1
2
3
4
5
6
7
8
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