Mitsubishi Electric FR-A700 Technical Manual page 306

2.14.2 Overvoltage stall prevention operation level
If the regenerative energy of the motor at deceleration
becomes excessive and DC bus voltage exceeds the
specified value, this function stops the decrease in
frequency for 3s maximum to prevent overvoltage trip. As
soon as the regenerative energy has reduced, deceleration
resumes.
When overvoltage stall prevention is activated,
(overvoltage stall) appears and the OL signal is output.
Note that a stop distance extends if overvoltage stall
prevention operation activates.
Whether to perform overvoltage stall prevention or not is
selected using stall prevention operation selection of [Pr.
156] (refer to page 338). When stall prevention operation
disabled is selected using [Pr. 156], overcurrent stall
prevention operation is not also operated.
Model
55K or less
A700
200V
75K or more
55K or less
400V
75K or more
30K or less
F700
200V
37K or more
55K or less
400V
75K or more
200V
E700
400V
D700
2.14.3 Regeneration avoidance function [Pr. 665
common
(common)
This function detects a regeneration status and increases
the frequency to avoid the regeneration status.
It is possible to avoid regeneration by automatically
increasing the frequency and continue operation if a fan
[Pr. ] Name
Regeneration
882 avoidance
operation selection
200V
class
Regeneration
883 avoidance
operation level
400V
class
Regeneration
avoidance at
884
deceleration
detection sensitivity
Overvoltage Overvoltage
Stall Prevention Stall Prevention
Operation Start Operation
Level Cancel Level
390VDC 385VDC
385VDC 380VDC
780VDC 770VDC
785VDC 780VDC
390VDC 385VDC
385VDC 380VDC
780VDC 770VDC
785VDC 780VDC
400VDC 395VDC
780VDC 770VDC
Setting
Initial Value
Range
0
380VDC
A700 F700
400VDC
E700 D700
300 to
800V
760VDC
A700 F700
780VDC
E700 D700
0
1 to 5
(common)
* , 882, 883, 884*, 885, 886]
(*[Pr. 884] is not available for
happens to rotate faster than the set speed due to the
effect of another fan in the same duct.
Description
0 Regeneration avoidance function invalid
1 Regeneration avoidance function is always valid
Regeneration avoidance function is valid only during
2
a constant speed operation
Set the bus voltage level at which regeneration
avoidance operates. When the bus voltage level is
set to low, overvoltage error will be less apt to occur.
However, the actual deceleration time increases.
The set value must be higher than the power supply
voltage x .
Regeneration avoidance by bus voltage change
0
ratio is invalid
Set sensitivity to detect the bus voltage change ratio.
Setting 1
Detection sensitivity low
340
common
OL
Overvoltage stall prevention operation example
(*[Pr. 665] is not available for
Available Inverters
A700
5
high
PARAMETER
Time
Time
.)
F700
.)
E700 D700
F700
E700 D700
—