Mitsubishi Electric FR-A700 Series, Technical Manual

Page: 306 / 550

340
PARAMETER
2.14.2 Overvoltage stall prevention operation level
(common)
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.
2.14.3 Regeneration avoidance function [Pr. 665 * , 882, 883, 884*, 885, 886]
(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 happens to rotate faster than the set speed due to the
effect of another fan in the same duct.
common
Base voltage
(DCV)
OL
Time
Output
frequency
(H
Z
)
Overvoltage stall prevention operation example
Time
Model
Overvoltage
Stall Prevention
Operation Start
Level
Overvoltage
Stall Prevention
Operation
Cancel Level
200V
55K or less 390VDC 385VDC
75K or more 385VDC 380VDC
400V
55K or less 780VDC 770VDC
75K or more 785VDC 780VDC
200V
30K or less 390VDC 385VDC
37K or more 385VDC 380VDC
400V
55K or less 780VDC 770VDC
75K or more 785VDC 780VDC
200V 400VDC 395VDC
400V 780VDC 770VDC
A700
F700
E700
D700
(*[Pr. 665] is not available for .)
(*[Pr. 884] is not available for .)
common
F700
E700 D700
[Pr. ] Name Initial Value
Setting
Range
Description
Available Inverters
882
Regeneration
avoidance
operation selection
0
0 Regeneration avoidance function invalid
{ { {
1 Regeneration avoidance function is always valid
2
Regeneration avoidance function is valid only during
a constant speed operation
883
Regeneration
avoidance
operation level
200V
class
380VDC
400VDC
300 to
800V
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 .
{ { {
400V
class
760VDC
780VDC
884
Regeneration
avoidance at
deceleration
detection sensitivity
0
0
Regeneration avoidance by bus voltage change
ratio is invalid
{ {
—
1 to 5
Set sensitivity to detect the bus voltage change ratio.
Setting 1 5
Detection sensitivity low high
A700 F700
E700 D700
A700 F700
E700 D700
A700 F700
E700 D700