Danfoss VLT AutomationDrive FC 300 Programming Manual page 52

Parameter Descriptions
2-15 Brake Check
Option: Function:
[1] Warning Monitors brake resistor and brake IGBT for a short-
circuit, and runs a test for brake resistor
disconnection during power-up.
[2] Trip Monitors for a short-circuit or disconnection of the
brake resistor, or a short-circuit of the brake IGBT.
If a fault occurs, the frequency converter cuts out
while displaying an alarm (trip locked).
[3] Stop and Monitors for a short-circuit or disconnection of the
trip brake resistor, or a short-circuit of the brake IGBT.
If a fault occurs, the frequency converter ramps
down to coast and then trips. A trip lock alarm is
displayed (e.g. warning 25, 27 or 28).
[4] AC brake Monitors for a short-circuit or disconnection of the
brake resistor, or a short-circuit of the brake IGBT.
If a fault occurs, the frequency converter performs
a controlled ramp-down. This option is available
for FC 302 only.
[5] Trip Lock
NOTE
Remove a warning arising in connection with Off [0] or
Warning [1] by cycling the mains supply. The fault must be
corrected first. For Off [0] or Warning [1], the frequency
converter keeps running even if a fault is located.
This parameter is only active in frequency converters with an
integral dynamic brake.
2-16 AC brake Max. Current
Range: Function:
100.0 % [Application Enter the maximum permissible
*
dependant] current when using AC brake to
avoid overheating of motor
windings. The AC brake function is
available in Flux mode only (FC 302
only).
2-17 Over-voltage Control
Option: Function:
Over-voltage control (OVC) reduces the risk
of the frequency converter tripping due to
an over voltage on the DC link caused by
generative power from the load.
[0] Disabled No OVC required.
*
[1] Enabled (not at Activates OVC except when using a stop
stop) signal to stop the frequency converter.
FC 300 Programming Guide
2-17 Over-voltage Control
Option:
[2]
NOTE
OVC must not be enabled in hoisting applications.
2-18 Brake Check Condition
Range:
[0]
[1]
2-19 Over-voltage Gain
Range:
100 %
3.4.3 2-2* Mechanical Brake
Parameters for controlling operation of an electro-magnetic
(mechanical) brake, typically required in hoisting
applications.
To control a mechanical brake, 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, e.g. due to an excessive load. Select Mechanical Brake
Control [32] for applications with an electro-magnetic brake
in 5-40 Function Relay, 5-30 Terminal 27 Digital Output, or
5-31 Terminal 29 Digital Output. When selecting Mechanical
brake control [32], the mechanical brake is closed from start
up until the output current is above the level selected in
2-20 Release Brake Current. During stop, the mechanical brake
activates when the speed falls below the level specified in
2-21 Activate Brake Speed [RPM]. If the frequency converter
enters an alarm condition or an over-current or over-voltage
situation, the mechanical brake immediately cuts in. This is
also the case during safe stop.
NOTE
Protection mode and trip delay features (14-25 Trip Delay at
Torque Limit and 14-26 Trip Delay at Inverter Fault) may delay
the activation of the mechanical brake in an alarm condition.
These features must be disabled in hoisting applications.
®
MG.33.MB.02 - VLT is a registered Danfoss trademark
Function:
Enabled Activates OVC.
Function:
At Power Up Brake check will be performed at
*
power up
After Coast Situations Brake check will be performed after
coast situations
Function:
[0 - 200 %] Select over-voltage gain.
*
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