Mitsubishi Electric FR-D720S SC EC Instruction Manual page 417

Parameter
6.19.4 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 regener-
ation status.
Possible to avoid regeneration by automatically increasing the frequency and continue opera-
tion if the fan happens to rotate faster than the set speed due to the effect of another fan in the
same duct.
Pr. No. Name
Regeneration
882
avoidance operation
selection
Regeneration
883
avoidance operation
level
Regeneration
avoidance
885
compensation
frequency limit value
Regeneration
886
avoidance voltage
gain
Regeneration avoid-
665
ance frequency gain
The above parameters can be set when Pr. 160 = 0.
FR-D700 SC EC
Initial Setting
Value Range
0
1
0
2
200V
400V DC
class
300–800V
400V
780V DC
class
0–10Hz
6Hz
9999
100% 0–200%
100% 0–200%
Description
Regeneration avoidance function
invalid
Regeneration avoidance function is
always valid
Regeneration avoidance function is
valid only during a constant speed
operation
Set the bus voltage level at which
regeneration avoidance operates.
When the bus voltage level is set to
low, over voltage error will be less apt
to occur. However, the actual decelera-
tion time increases. The set value
must be higher than the power supply
voltage × √2.
Set the limit value of frequency which
rises at activation of regeneration
avoidance function.
Frequency limit invalid
Responsiveness at activation of regen-
eration avoidance.
A larger setting will improve respon-
siveness to the bus voltage change.
However, the output frequency could
become unstable. When vibration is
not suppressed by decreasing the
Pr. 886 setting, set a smaller value in
Pr. 665.
Special operation
Refer to
Parameters referred to
Section
1 Maximum 6.3.1
frequency
8 Deceleration time 6.6.1
22 Stall prevention 6.2.4
operation level
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