123
Brake engage time
Parameter Description
This parameter determines how long the drive will maintain full
current and control of the motor after the direction inputs, X2A.14
and X2A.15 have been turned off. After the adjusted time, motor
current will continue to ow, however the analog input will be
clamped and the speed control gains will be reduced. This time
should be adjusted longer than the actual required time for the
brake to mechanically drop.
Note: when using digital speed selection the selected speed
input must be turned off before or at the same time as the
direction input is turned off. When using analog or serial speed
control, the command speed should be brought to zero before
turning off the direction signal.
Unit: seconds
Value range: 0.00 … 3.00 Seconds
Default setting: 0.50 Seconds
Current hold time
Once the time in LF.78 has expired, current will continue owing
to the motor, but the drive will ramp the motor torque down to zero
over the time adjusted in LF.79. This provides a smooth transition
of the load to the brake and a quiet de-energization of the motor.
This time should be adjusted such that the drive shuts off the
current before the controller drops the drive enable (X2A.16) and
opens the motor contactor. If the drive enable is dropped before
the current is shut off, it is possible the drive will respond with
base block protection “BBL” with can prevent further operation for
1 to 3 seconds depending on the drive size. Therefore the times
should be adjusted to prevent this. Additionally during this time
the speed control is turned off to prevent the motor from driving
against the brake.
The total time between the drop of the direction signals
(X2A.14 & X2A.15) and the turn off of motor current is LF.78
+ LF.79. The time delay for dropping the enable (X2A.16) and
the opening of the motor contact should be greater than the
sum of LF.78 and LF.79.
Unit: seconds
Value range: 0.1 … 0.5 Seconds
Default setting: 0.3 Seconds
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