Danfoss VLT AutomationDrive FC 301 Programming Manual page 115

VLT AutomationDrive FC 301/302
Programming Guide
Parameter 2-12 Brake Power Limit (kW)
Table 160: Parameter 2-12 Brake Power Limit (kW)
2-12 Brake Power Limit (kW)
Default value: Size related
Conversion index: 0
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 thereby specifies when a warning/alarm is to be given. To
calculate parameter 2-12 Brake Power Limit (kW), the following formula can be used.
2
U V × t s
br br
P W =
br, avg
R Ω × T s
br br
P is the average power dissipated in the brake resistor. R
br,avg
within the 120 s period, T . U
br
• T2 units: 390 V
• T4 units: 810 V
• T5 units: 810 V
• T6 units: 943 V/1099 V for D–F enclosures
• T7 units: 1099 V
If R is not known, or if T is different from 120 s, the practical approach is to run the brake application, read parameter 16-33
br br
Brake Energy Average and then enter this + 20% in parameter 2-12 Brake Power Limit (kW).
Parameter 2-13 Brake Power Monitoring
Table 161: Parameter 2-13 Brake Power Monitoring
2-13 Brake Power Monitoring
Default value: [0] Off
Conversion index: –
This parameter is only active in drives with a brake. This parameter enables monitoring of the power to the brake resistor. The pow-
er is calculated based on the resistance (parameter 2-11 Brake Resistor (ohm)), the DC-link voltage, and the resistor duty time. If pow-
er monitoring is set to [0] Off or [1] Warning, the brake function remains active, even if the monitoring limit is exceeded. This may
lead to thermal overload of the resistor. It is also possible to generate a warning via a relay/digital output. The measuring accuracy
of the power monitoring depends on the accuracy of the resistance of the resistor (better than ±20%).
Option Name
[0]* Off
[1] Warning 120s
[2] Trip 120s
[3] Warning & Trip 120s
[4] Warning 30s
[5] Trip 30s
Danfoss A/S © 2022.12
Parameter type: Range, 0.001 - 2000.000 kW
Data type: Uint32
is the DC voltage where the brake resistor is active. This depends on the unit as follows:
br
N O T I C E
Parameter type: Option
Data type: Uint8
Description
No brake power monitoring required.
Activates a warning on the display when the power transmitted during the duty time exceeds
100% of the monitoring limit (parameter 2-12 Brake Power Limit (kW)). The warning disappears
when the transmitted power drops below 80% of the monitoring limit.
Trips the drive and shows an alarm when the calculated power exceeds 100% of the monitoring
limit.
Activates both of the above, including warning, trip, and alarm.
is the resistance of the brake resistor. t
br
Setup: All setups
Change during operation: True
Parameter Descriptions
Setup: All setups
Change during operation: True
is the active braking time
br
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