2-11 Brake Resistor (ohm)
Range:
Function:
converters with an integral dynamic brake.
Use this parameter for values without
decimals.
2-12 Brake Power Limit (kW)
Range:
Function:
Size
related
*
[0.001 -
2000
kW]
Parameter 2-12 Brake Power Limit (kW)
is the
expected average power dissipated in the
brake resistor over a period of 120 s. It is
used as the monitoring limit for
parameter 16-33 Brake Energy Average
and
specifies when a warning/alarm is given.
To calculate
parameter 2-12 Brake Power
Limit (kW)
, the following formula can be
used.
P
br, avg
W =
U
br
2
V × t
br
s
R
br
Ω × T
br
s
P
br,avg
is the average power dissipated in
the brake resistor, R
br
is the resistance of
the brake resistor. t
br
is the active breaking
time within the 120 s period, T
br
.
U
br
is the DC voltage where the brake
resistor is active. For T4 units, the DC
voltage is 778 V, which can be reduced by
parameter 2-14 Brake voltage reduce
NOTICE
If R
br
is not known or if T
br
is different
from 120 s, the practical approach is
to run the brake application, read out
parameter 16-33 Brake Energy Average
,
and then enter this value + 20% in
parameter 2-12 Brake Power Limit
(kW)
.
2-14 Brake voltage reduce
Range:
Function:
0 V
*
[ 0 - 0 V] Setting this parameter may change the brake
resistor (
parameter 2-11 Brake Resistor (ohm)
).
2-16 AC Brake, Max current
Range:
Function:
100 %
*
[0 -
160 %]
Enter the maximum permissible current
when using AC brake to avoid overheating
of motor windings.
NOTICE
Parameter 2-16 AC Brake, Max current
has no effect when
parameter 1-10 Motor Construction
is
set to
[1] PM, non-salient SPM
.
2-17 Over-voltage Control
Option:
Function:
Overvoltage control (OVC) reduces the risk of
the frequency converter tripping due to an
overvoltage on the DC link caused by
generative power from the load.
[0]
*
Disabled
No OVC required.
[1]
Enabled
(not at
stop)
Activates OVC except when using a stop signal
to stop the frequency converter.
[2]
Enabled
Activates OVC.
WARNING
PERSONAL INJURY AND EQUIPMENT
DAMAGE
Enabling OVC in hoisting applications
may lead to personal injuries and
equipment damage. Do not enable OVC
in such applications.
2-19 Over-voltage Gain
Range:
Function:
100 %
*
[0 - 200 %]
Select overvoltage gain.
4.3.3 2-2* Mechanical Brake
2-20 Release Brake Current
Range:
Function:
0 A
*
[0 -
100 A]
Set the motor current for release of the
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
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.
2-22 Activate Brake Speed [Hz]
Range:
Function:
0 Hz
*
[0 - 400 Hz] Set the motor frequency for activation of
the mechanical brake when a stop
condition is present.
Parameter Descriptions
VLT
®
AutomationDrive FC 360
38
Danfoss A/S © 7/2015 All rights reserved.
MG06C602
4
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