Mitsubishi Electric FR-F740 EC Instruction Manual page 316

Operation selection at power failure
Power failure stop function (with DC bus voltage constant control) (Pr. 261 = 21)
Deceleration time is automatically adjusted to keep (DC bus) voltage constant in the converter
when the inverter decelerates to a stop. Even if power is restored during power failure decel-
eration, deceleration to a stop is continued and the inverter remains stopped. To restart, turn
OFF the start signal once, then turn it ON again.
Setting Pr. 261 = "21" disables the settings of Pr. 262 to Pr. 266.
Fig. 6-99:
NOTES
Power supply
When automatic restart after instantaneous power failure is selected (Pr. 57 ≠ "9999"),
deceleration to stop function is invalid and the restart after instantaneous power failure oper-
ation is performed.
When the power failure deceleration stop function is active (Pr. 261 = "1" or "21"), the
inverter will not start even if the power is turned ON with the start signal (STF/STR) ON.
After switching ON the power supply, turn OFF the start signal once and then ON again to
make a start.
6 - 166
Pr. 261 = 21
Power supply
Turn OFF STF once to make acceleration again
Power failure stop function
ON
Not started as inverter is
stopped due to power
failure
During deceleration at occurrence of power failure
Deceleration time: automatically adjusted
During stop at
occurrence of
power failure
Output
frequency
Time
OFF
ON
Parameter
Time
I002099E