Danfoss FC 300

2.15.5. 14-3* Current Limit Control
The FC 300 Series features an integral Current Limit Controller which is activated when the motor
current, and thus the torque, is higher than the torque limits set in par. 4-16 and 4-17.
When the current limit is reached during motor operation or regenerative operation, the frequency
converter will try to reduce torque below the preset torque limits as quickly as possible without
losing control of the motor.
While the current control is active, the frequency converter can only be stopped by setting a digital
input to
Coast inverse [2] or Coast and reset inv. [3]. Any signal on terminals 18 to 33 will not be
active until the frequency converter is no longer near the current limit.
By using a digital input set to
Coast inverse [2] or Coast and reset inv. [3], the motor does not
use the ramp-down time, since the drive is coasted. If a quick stop is necessary, use the me-
chanical brake control function along with an external electro-mechanical brake attached to the
application.
14-30 Current Lim Cont, Proportional Gain
Range: Function:
100 %
*
[0 - 500 %] Enter the proportional gain value for the current limit controller.
Selection of a high value makes the controller react faster. Too
high a setting leads to controller instability.
14-31 Current Lim Contr, Integration Time
Range: Function:
0.020 s
*
[0.002 - 2.000 s] Controls the current limit control integration time. Setting it to
a lower value makes it react faster. A setting too low leads to
control instabillity.
2.15.6. 14-4* Energy Optimising
Parameters for adjusting the energy optimi-
sation level in both Variable Torque (VT) and
Automatic Energy Optimization (AEO) mode in
par. 1-03.
14-40 VT Level
Range: Function:
66%
*
[40 - 90%] Enter the level of motor magnetisation at low speed. Selection
of a low value reduces energy loss in the motor, but also reduces
load capability.
This parameter cannot be adjusted while the motor is running.
14-41 AEO Minimum Magnetisation
Range: Function:
40%
*
[40 - 75%] Enter the minimum allowable magnetisation for AEO. Selection
of a low value reduces energy loss in the motor, but can also
reduce resistance to sudden load changes.
2. How to Programme FC 300 Programming Guide
178 MG.33.M2.02 - VLT
®
is a registered Danfoss trademark
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