Mitsubishi Electric FR-A740-00023 Instruction Manual page 269

Pr.261 = 1
Power
supply
During deceleration at
occurrence of power failure
During stop at
occurrence of
power failure
STF
Y46
Turn off STF once to make acceleration again
(4) Original operation continuation at instantaneous power failure function (Pr. 261 = "2, 12")
⋅ When power is restored during deceleration after an instantaneous power failure, acceleration is made again up to
the set frequency.
⋅ When this function is used in combination with the automatic restart after instantaneous power failure operation,
deceleration can be made at a power failure and acceleration can be made again after power restoration. When
power is restored after a stop by deceleration at an instantaneous power failure, automatic restart operation is
performed if automatic restart after instantaneous power failure has been selected (Pr. 57 ≠ "9999")
When power is restored during
Pr. 261 = 2
deceleration at occurrence of
power failure
IPF
Power
supply
Output
frequency
During deceleration
at occurrence of
power failure
Y46
* Acceleration time depends on Pr. 7 (Pr. 44 ).
(5) Undervoltage avoidance function (Pr. 261 = "11, 12", Pr. 294 )
⋅ When Pr. 261 = "11, 12", the deceleration time is automatically adjusted (shortened) to prevent undervoltage from
occuring during deceleration at an instantaneous power failure.
⋅ Adjust the slope of frequency decrease and response level with Pr. 294. A larger setting will improve
responsiveness to the bus voltage.
REMARKS
Undervoltage avoidance function is invalid during torque control by real sensorless vector control. When Pr. 261 = "11 (12)", the
inverter operates in the same manner as when "1 (2)" is set in Pr. 261.
(3) Power failure stop mode (Pr. 261 = "1, 11")
⋅ If power is restored during power failure deceleration, deceleration to
a stop is continued and the inverter remains stopped. To restart, turn
off the start signal once, then turn it on again.
REMARKS
Power supply
Time
⋅
When automatic restart after instantaneous power failure is selected (Pr.
≠
"9999"), deceleration to stop function is invalid and the restart after
57
instantaneous power failure operation is performed.
⋅
After a power failure stop, the inverter will not start if the power supply is switched
on with the start signal (STF/STR) input. After switching on the power supply, turn
off the start signal once and then on again to make a start.
Power
supply
Output
frequency
Reacceleration*
Time
Y46
Operation selection at power failure
and instantaneous power failure
ON
Not started as inverter
is stopped due to power
failure
STF
OFF
Y46
When used with automatic restart
Pr.261 = 2, Pr.57 9999
after instantaneous power failure
During power failure
During deceleration
at occurrence of
power failure
Output
frequency
Time
ON
Automatic restart
after instantaneous
power failure
Time
Reset time + Pr.57
259
4