Danfoss VLT AutomationDrive FC 300 Programming Manual page 61

Parameter Descriptions
2-20 Release Brake Current
Range: Function:
Size [ 0 - par. Set the motor current for release of the
related 16-37 A] mechanical brake, when a start condition
*
is present. The default value is the
maximum current the inverter can
provide for the particular power size. The
upper limit is specified in 16-37 Inv. Max.
Current.
NOTE
When Mechanical brake control
output is selected but no mechanical
brake is connected, the function will
not work by default setting due to
too low motor current.
2-21 Activate Brake Speed [RPM]
Range: Function:
Size related [0 - 30000 Set the motor speed for activation
*
RPM] of the mechanical brake, when a
stop condition is present. The upper
speed limit is specified in
4-53 Warning Speed High.
2-22 Activate Brake Speed [Hz]
Range:
Size related [ 0 - 5000.0 Hz] Set the motor frequency for
*
2-23 Activate Brake Delay
Range: Function:
0 s [0 - Enter the brake delay time of the coast after ramp-
*
5 s] down time. The shaft is held at zero speed with full
holding torque. Ensure that the mechanical brake
has locked the load before the motor enters coast
mode. See Mechanical Brake Control section in the
Design Guide.
To adjust transition of the load to the mechanical
brake, set 2-23 Activate Brake Delay and 2-24 Stop
Delay.
Setting of brake delay parameters does not impact
the torque. The frequency converter does not
register that mechanical brake is holding the load.
®
VLT AutomationDrive Programming Guide
Function:
activation of the mechanical
brake, when a stop condition is
present.
®
MG33MG02 - VLT is a registered Danfoss trademark
2-23 Activate Brake Delay
Range: Function:
After setting 2-23 Activate Brake Delay the torque
drops to zero in few minutes. The sudden torque
change leads to movement and noise.
2-24 Stop Delay
Range: Function:
0 s [0 - 5 s] Set the time interval from the moment when the
*
motor is stopped until the brake closes.
To adjust transition of the load to the mechanical
brake, set 2-23 Activate Brake Delay and 2-24 Stop
Delay.
This parameter is a part of the stopping function.
2-25 Brake Release Time
Range: Function:
0.20 s [0 - 5 s] This value defines the time it takes for the
*
mechanical brake to open. This parameter
must act as a time-out when brake feedback is
activated.
2-26 Torque Ref
Range: Function:
0 % [ 0 - The value defines the torque applied against the
*
0 %] closed mechanical brake, before release.
The torque/load on a crane is positive and
between 10% and 160%.To obtain the best starting
point, set 2-26 Torque Ref to approximately 70%.
The torque/load on a lift can be both positive and
negative and between -160% and 160% To obtain
the best starting point, set 2-26 Torque Ref to 0%.
The higher the torque error (2-26 Torque Ref vs.
actual torque) is, the more movement during load
take over.
2-27 Torque Ramp Up Time
Range: Function:
0.2 s [0 - 5 s] The value defines the duration of the torque
*
ramp in clockwise direction.
2-28 Gain Boost Factor
Range: Function:
1 [0 - 4 ] Only active in flux closed loop. The function
*
ensures a smooth transition from torque control
mode to speed control mode when the motor
takes over the load from the brake.
Increase to minimise the movement. Activate the
Advanced Mechanical Brake (parameter group 2-3*)
by setting 2-28 Gain Boost Factor to 0.
3 3
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