Power Failure-Time Deceleration-To-Stop Function (Pr. 261 To Pr. 266, Pr. 294 ) - Mitsubishi Electric FR-A720-0.4K Instruction Manual

Operation selection at power failure
and instantaneous power failure

4.17.2 Power failure-time deceleration-to-stop function (Pr. 261 to Pr. 266, Pr. 294 )

When a power failure or undervoltage occurs, the inverter can be decelerated to a stop or can be decelerated
and re-accelerated to the set frequency.
Parameter
Name
Number
Power failure stop
261
selection
Subtracted frequency at
262
deceleration start
Subtraction starting
263
frequency
Power-failure deceleration
264
time 1
Power-failure deceleration
265
time 2
Power failure deceleration
266
time switchover frequency
294 UV avoidance voltage gain
* When the setting of Pr. 21 Acceleration/deceleration time increments is "0" (initial value), the setting range is "0 to 3600s" and the setting increments are
"0.1s", and when the setting is "1", the setting range is "0 to 360s" and the setting increments are "0.01s"
Power supply
Remove the jumper
Connect terminals
R1/L11 and P/+
and terminals
S1/L21 and N/-.
Power supply
Output
Subtracted
frequency
frequency at
Power-failure deceleration start
deceleration Pr.262
time switchover
frequency
Pr.266
270
Initial
Setting Range
Value
0
1
0
11
2
12
3Hz 0 to 20Hz
0 to 120Hz
60Hz
9999
5s 0 to 3600/ 360s *
0 to 3600/ 360s *
9999
9999
60Hz 0 to 400Hz
100% 0 to 200%
(1) Connection and parameter setting
Inverter
⋅ Remove the jumpers across terminals R/L1-R1/L11 and
R/L1
across terminals S/L2-S1/L21, and connect terminals R1/
S/L2
L11 and P/+ and terminals S1/L21 and N/-.
T/L3
R1/L11
⋅ When setting of Pr. 261 is not "0", the motor decelerates to a
S1/L21
stop if an undervoltage, power failure or input phase loss
P/+
(when Pr. 872 ="1"(input phase loss enabled)) occurs.
N/−
(2) Operation outline of deceleration to stop at
Pr.264
Power-failure
⋅ If an undervoltage or power failure occurs, the output
deceleration time 1
frequency is dropped by the frequency set in Pr. 262 .
Pr.265
⋅ Deceleration is made in the deceleration time set in Pr. 264.
Power-failure
deceleration
(The deceleration time setting is the time required from Pr. 20
time 2
Acceleration/deceleration reference frequency to a stop.)
Time
⋅ When the frequency is low and enough regeneration energy
is not provided, for example, the deceleration time (slope)
from Pr. 265 to a stop can be changed.
Description
Coasting to stop
When undervoltage or power failure occurs, the inverter output
is shut off.
Without under
When undervoltage or a power failure
voltage avoidance
occurs, the inverter can be decelerated
With under
to a stop.
voltage avoidance
Without under When undervoltage or a power failure
voltage avoidance occurs, the inverter can be decelerated
to a stop.
With under
If power is restored during a power
voltage avoidance
failure, the inverter accelerates again.
Normally operation can be performed with the initial value
unchanged. But adjust the frequency according to the
magnitude of the load specifications (moment of inertia, torque).
When output frequency ≥ Pr. 263
Decelerate from the speed obtained from output frequency
minus Pr. 262.
When output frequency < Pr. 263
Decelerate from output frequency
Decelerate from the speed obtained from output frequency
minus Pr. 262.
Set a deceleration slope down to the frequency set in Pr. 266.
Set a deceleration slope below the frequency set in Pr. 266.
Same slope as in Pr. 264
Set the frequency at which the deceleration slope is switched
from the Pr. 264 setting to the Pr. 265 setting.
Adjust the response level during undervoltage avoidance
operation. A larger setting will improve responsiveness to the
bus voltage change.
power failure