Regeneration Avoidance Function (Pr. 665, Pr. 882, Pr. 883, Pr. 885, Pr. 886) - Mitsubishi Electric FR-E720-0.1K(SC) Instruction Manual

4.21.4 Regeneration avoidance function (Pr. 665, Pr. 882, Pr. 883, Pr. 885, Pr. 886)

This function detects a regeneration status and increases the frequency to avoid the regenerative status.
Possible to avoid regeneration by automatically increasing the frequency and continue operation if the fan happens
to rotate faster than the set speed due to the effect of another fan in the same duct.
Parameter
Name
Number
Regeneration
882 avoidance operation
selection
Regeneration
883 avoidance operation
level
Regeneration
avoidance
885
compensation
frequency limit value
Regeneration
886 avoidance voltage
gain
Regeneration
665 avoidance frequency
gain
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 188)
∗ For the single-phase 100V power input model, power input voltage
(1) What is regeneration avoidance function? (Pr. 882, Pr. 883)
When the regeneration load is large, the DC bus voltage rises and an overvoltage fault (E. OV ) may occur.
When this bus voltage rise is detected and the bus voltage level reaches or exceeds Pr. 883, increasing the frequency
avoids the regeneration status.
The regeneration avoidance function is always ON when "1" is set in Pr. 882 and activated only during a constant speed
when "2" is set in Pr. 882.
Regeneration avoidance operation example
for acceleration
Pr. 883
During regeneration
avoidance function operation
Regeneration avoidance
operation example for deceleration
Pr. 883
During regeneration
avoidance function operation
Special operation and frequency control
Setting
Initial Value
Range
0 Regeneration avoidance function invalid
1 Regeneration avoidance function is always valid
0
Regeneration avoidance function is valid only during a constant
2
speed operation
100V
class, 400
Bus voltage level at which regeneration avoidance operates. When
200V VDC
the bus voltage level is set to low, overvoltage error will be less apt
300 to 800V
class
to occur. However, the actual deceleration time increases.
400V 780
The set value must be higher than the "power supply voltage ×
class VDC
Limit value of frequency which rises at activation of regeneration
0 to 10Hz
avoidance function.
6Hz
9999 Frequency limit invalid
Responsiveness at activation of regeneration avoidance.
100% 0 to 200%
A larger setting will improve responsiveness to the bus voltage
change. However, the output frequency could become unstable.
When vibration is not suppressed by decreasing the Pr. 886 setting,
100% 0 to 200%
set a smaller value in Pr. 665.
× ×
2 .
2
Regeneration avoidance operation example
for constant speed
Time
Time
Time
Time
Description
Pr. 883
During regeneration avoidance
function operation
2
". *
4
Time
Time
261