Mitsubishi Electric FR-A800, Instruction Manual

Page: 868 / 1042

(G) Control parameters Parameters
5 - 688
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) or brake resistor (FR-ABR, etc.).
When using regeneration unit (FR-BU2, BU, FR-BU, FR-CV, FR-HC2) or brake resistor (FR-ABR, etc.)
to consume the regenerative power, set to Pr. 882 = "0 (initial value)" (disables regeneration avoid-
ance function). When consuming 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).
When using the vector control and the regeneration avoidance function together, there may be a
sound from the motor at the time of deceleration. In such case, adjust the gain by performing easy
gain tuning, etc. (Refer to page 5-67.)
Parameters referred to
Pr. 1 Maximum frequency => page 5-310
Pr. 8 Deceleration time => page 5-233
Pr. 22 Stall prevention operation level => page 5-84