Mitsubishi Electric FR-F820-00077 Instruction Manual page 735

Parameters
Adjustment of regeneration avoidance operation (Pr. 665, Pr. 886)
● When the frequency becomes unstable at the time of regeneration avoidance operation, set the
setting value for Pr. 886 "Regeneration avoidance voltage gain" smaller. On the other hand, if an
overvoltage fault occurs due to a sudden regeneration, increase the setting.
● When the vibration cannot be stabilized even if the setting value of Pr. 886 is made smaller, set
the setting value of Pr. 665 "Regeneration avoidance frequency gain" smaller.
NOTES During the regeneration avoidance operation, the stall prevention (overvoltage) (oL) is displayed
and the overload alarm (OL) signal is output. The operation when the OL signal is output can be
set with Pr. 156 "Stall prevention operation selection". The OL signal output timing can be set with
Pr. 157 "OL signal output timer".
The stall prevention is enabled even at the time of regeneration avoidance operation.
The regeneration avoidance function cannot decrease the actual deceleration time for the motor
to stop. The actual deceleration time is determined by the regenerative power consumption per-
formance, so to decrease the deceleration time, consider using a regeneration unit (FR-BU2, BU,
FR-BU, FR-CV, FR-HC2).
When using regeneration unit (FR-BU2, BU, FR-BU, FR-CV, FR-HC2) to consume the regenerative
power, set to Pr. 882 = "0 (initial value)" (disables regeneration avoidance function). When con-
suming the regenerative power at the time of deceleration with the regeneration unit, etc., set to
Pr. 882 = "2" (enables regeneration avoidance function only at the time of constant speed).
Parameters referred to
Pr. 1
Pr. 8
Pr. 22
FR-F800
Maximum frequency
Deceleration time
Stall prevention operation level
(G) Control parameters
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