Regeneration Avoidance Function (Pr.882 To Pr.886) - Mitsubishi Electric F700 Instruction Manual

Special operation and frequency setting

3.19.5 Regeneration avoidance function (Pr.882 to Pr.886)

This function detects a regeneration status and increases the frequency to avoid the regeneration status.
Pr.872
Possible to avoid regeneration by automatically increasing the frequency and continue operation if the fan
page 117
Pr.888 happens to rotate in the opposite direction due to the effect of another fan in the same duct.
page 216
Parameter
Number
Regeneration
882 avoidance operation
selection
Regeneration
883 avoidance operation
level
Regeneration
avoidance at
884
deceleration
detection sensitivity
Regeneration
avoidance
885
compensation
frequency limit value
Regeneration
886 avoidance voltage
gain
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 140)
(1) What is regeneration avoidance function? (Pr.882, Pr.883)
⋅ When the regeneration status is serious, the DC bus voltage rises and an overvoltage alarm (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 performed during any of acceleration, constant speed and deceleration.
Regeneration avoidance operation
example for acceleration
Pr.883
During regeneration
avoidance function operation
⋅ Setting Pr. 882 to "1" validates the regeneration avoidance function.
REMARKS
⋅ The inclination of the frequency increased or decreased by the regeneration avoidance function changes depending on the
regeneration status.
⋅ The DC bus voltage of the inverter is normally about
440VAC, the bus voltage is about 622VDC). However, it varies with the input power supply waveform.
⋅ The Pr. 883 setting should be kept higher than the DC bus voltage level. Otherwise, the regeneration avoidance function is
always on.
⋅ While overvoltage stall (
on and increases the frequency according to the regeneration amount.
208
Initial
Name
Value
0
760VDC
0
6Hz
100%
Regeneration avoidance operation
example for constant speed
Time
Time
) stops the output frequency during deceleration, the regeneration avoidance function is always
Setting
Range
0 Regeneration avoidance function invalid
1 Regeneration avoidance function valid
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
300 to 800V
actual deceleration time increases. The set value must be
higher than the power supply valtage ×
Regeneration avoidance by bus voltage change ratio is
0
invalid
Set sensitivity to detect the bus voltage change
1 to 5 Setting
Detection sensitivity low
Set the limit value of frequency which rises at activation of
0 to 10Hz
regeneration avoidance function.
9999 Frequency limit invalid
Adjust responsiveness at activation of regeneration
avoidance. A larger setting will improve responsiveness to
0 to 200%
the bus voltage change. However, the output frequency
could become unstable.
Pr.883
Time
During regeneration
avoidance function operation
Time
times greater than the input voltage (when the input voltage is
2
Description
.
2
1 5
high
Regeneration avoidance operation
example for deceleration
Pr.883
During regeneration
avoidance function operation
Time
Time