Danfoss VLT AutomationDrive FC 301 Programming Manual page 64

Parameter Descriptions
3.3.3 2-2* Mechanical Brake
Parameters for controlling operation of an electro-magnetic
(mechanical) brake, typically required in hoisting
applications.
3 3
To control a mechanical braking, a relay output (relay 01 or
relay 02) or a programmed digital output (terminal 27 or
29) is required. Normally, this output must be closed
during periods when the frequency converter is unable to
hold the motor, for example due to an excessive load.
Select [32] Mechanical Brake Control for applications with
an electro-magnetic brake in parameter 5-40 Function Relay,
parameter 5-30 Terminal 27 Digital Output, or
parameter 5-31 Terminal 29 Digital Output. When selecting
[32] Mechanical brake control, the mechanical braking is
closed from start-up until the output current is above the
Start
1=on
term.18
0=o
Par 1-71
Start delay time
Shaft speed
Output current
Pre-magnetizing
current or
DC hold current
Par 2-23
Brake delay time
Relay 01
Mechanical brake
locked
Mechanical brake
free
Illustration 3.19 Mechanical Braking
2-20 Release Brake Current
Range:
par. [0.00 -
16-37 par.
A 16-37 A]
*
62
VLT
Par 1-74
Start speed
Par 1-76 Start current/
Par 2-00 DC hold current
Reaction time EMK brake
on
o
Function:
Set the motor current for release of the
mechanical braking 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 parameter 16-37 Inv. Max. Current.
Danfoss A/S © 01/2018 All rights reserved.
®
AutomationDrive FC 301/302
level selected in parameter 2-20 Release Brake Current.
During stop, the mechanical braking activates when the
speed drops below the level specified in
parameter 2-21 Activate Brake Speed [RPM]. If the frequency
converter enters an alarm condition, an overcurrent, or
overvoltage situation, the mechanical braking immediately
cuts in. This is also the case during Safe Torque Off.
NOTICE
Protection mode and trip delay features
(parameter 14-25 Trip Delay at Torque Limit and
parameter 14-26 Trip Delay at Inverter Fault) may delay
the activation of the mechanical braking in an alarm
condition. These features must be disabled in hoisting
applications.
Par 2-20
Release brake current
2-20 Release Brake Current
Range:
Par 2-21
Activate brake
speed
Time
Function:
NOTICE
When mechanical brake control output
is selected, but no mechanical braking
is connected, the function does not
work by default setting due to too low
motor current.
MG33MO02