Mitsubishi Electric FR-F820-04750 Instruction Manual page 590

(A) Application parameters
Outline of operation of deceleration stop at a power failure
● If an undervoltage or power failure occurs, the output frequency is turned OFF only for the
frequency set to Pr. 262 "Subtracted frequency at deceleration start".
● The motor decelerates for the time set to Pr. 264 "Power-failure deceleration time 1". (The decel-
eration time setting is the time it takes for the motor to stop from Pr. 20 "Acceleration/deceleration
reference frequency".)
● Change the deceleration time (slope) to the stop using Pr. 265 "Power-failure deceleration time"
2 when the frequency is too low to obtain the regenerative energy or in other instances.
Fig. 5-213:
Action setting at undervoltage and power failure
● Set Pr. 261 to select the action at an undervoltage and power failure.
Pr. 261
Setting
0
1
2
11
12
21
22
Tab. 5-211: Setting of Pr. 261
5 - 428
Power supply
Output
frequency
Power-failure
deceleration
time switchover
frequency
Pr. 266
Parameters for stop selection at power failure
Power restoration
Action at undervoltage during deceleration at
and power failure occurrence of power
failure
Coasts to stop Coasts to stop
Deceleration stop
Re-acceleration
Deceleration stop
Deceleration stop
Re-acceleration
Deceleration stop
Re-acceleration
Pr. 264
Subtracted
Power-failure
frequency at deceleration time 1
deceleration
start
Pr. 262
Deceleration stop time
—
According to Pr. 262 to
Pr. 266 setting
Automatic adjustment of
deceleration time
Parameters
Pr. 265
Power-failure
deceleration
time 2
Time
Undervoltage avoidance
function
—
Not used
Not used
With
With
Not used
Not used
I001173E