Danfoss VLT AutomationDrive FC 302 Programming Manual page 65

Parameter Descriptions
2-20 Release Brake Current
Range: Function:
Size [ 0 - Set the motor current for release of the
related par. mechanical brake when a start condition is
*
16-37 A] present. The default value is the maximum
current the inverter can provide for the
particular power size. The upper limit is
specified in parameter 16-37 Inv. Max.
Current.
NOTICE
When mechanical brake control
output is selected, but no mechanical
brake is connected, the function does
not work by default setting due to
too low motor current.
2-21 Activate Brake Speed [RPM]
Range: Function:
Size [0 - Set the motor speed for activation of
related 30000 the mechanical brake, when a stop
*
RPM] condition is present. The upper speed
limit is specified in
parameter 4-53 Warning Speed High.
2-22 Activate Brake Speed [Hz]
Range:
Size related [ 0 - 5000.0
*
Hz]
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 parameter 2-23 Activate Brake Delay and
parameter 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.
After setting parameter 2-23 Activate Brake Delay,
the torque drops to zero after a few minutes. The
MG33MJ02
Programming Guide
Function:
Set the motor frequency for
activation of the mechanical
brake when a stop condition is
present.
Danfoss A/S © Rev. 10/2014 All rights reserved.
2-23 Activate Brake Delay
Range: Function:
sudden torque change leads to movement and
noise.
2-24 Stop Delay
Range: Function:
0 s [0 - 5 Set the time interval from the moment when the
*
s] motor is stopped until the brake closes.
To adjust transition of the load to the mechanical
brake, set parameter 2-23 Activate Brake Delay and
parameter 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.
3.4.4 Hoist Mechanical Brake
The hoist mechanical break control supports the following
functions:
•
2 channels for mechanical brake feedback to offer
further protection against unintended behaviour
resulting from broken cable.
•
Monitoring of mechanical brake feedback
throughout the complete cycle. This helps protect
the mechanical brake, especially if more
frequency converters are connected to the same
shaft.
•
No ramp-up until feedback confirms mechanical
brake is open.
•
Improved load control at stop. If the value of
parameter 2-23 Activate Brake Delay is too small,
W22 is activated and the torque is not allowed to
ramp down.
•
The transition when motor takes over the load
from the brake can be configured. 2-28 Gain
Boost Factor can be increased to minimise the
movement. To achieve smooth transition, change
the setting from the speed control to the position
control during the change-over.
•
Set 2-28 Gain Boost Factor to 0 to enable
Position Control during 2-02 DC Braking
Time. This enables parameters 2-30 to
2-33, which are PID parameters for the
Position Control.
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