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2-10 Brake Function
Option:
Function:
[0] *
Off
No brake resistor installed.
[1]
Resistor brake
Brake resistor incorporated in the system, for dissipation of surplus brake energy as heat. Connect-
ing a brake resistor allows a higher DC link voltage during braking (generating operation). The
Resistor brake function is only active in frequency converters with an integral dynamic brake.
[2]
AC brake
2-11 Brake Resistor (ohm)
Range:
Function:
50.00
Ohm*
[5.00 - 65535.00 Ohm]
Set the brake resistor value in Ohms. This value is used for monitoring the power to the brake
resistor in par.2-13
. This parameter is only active in frequency converters
with an integral dynamic brake.
If the selection is xxxx use this parameter. If the selection is xxx.xx, use par. 3-81
Quick Stop Ramp
Time
.
2-12 Brake Power Limit (kW)
Range:
Function:
5.000 kW* [0.001 - 2000.000 kW]
Set the monitoring limit of the brake power transmitted to the resistor.
The monitoring limit is a product of the maximum duty cycle (120 sec.) and the maximum power
of the brake resistor at that duty cycle. See the formula below.
For 200 - 240 V units:
Presistor
= 390
2 ×
dutytime
R
× 120
For 380 - 480 V units:
Presistor
= 778
2 ×
dutytime
R
× 120
For 525 - 600 V units:
Presistor
= 943
2 ×
dutytime
R
× 120
This parameter is only active in frequency converters with an integral dynamic brake.
2-13 Brake Power Monitoring
Option:
Function:
This parameter is only active in frequency converters with an integral dynamic brake.
This parameter enables monitoring of the power to the brake resistor. The power is calculated on
the basis of the resistance (par.2-11
, the DC link voltage, and the resistor duty
time.
[0] *
Off
No brake power monitoring is required.
[1]
Warning
Activates a warning on the display when the power transmitted over 120 s exceeds 100% of the
monitoring limit (par.2-12
The warning disappears when the transmitted power falls below 80% of the monitoring limit.
[2]
Trip
Trips the frequency converter and displays an alarm when the calculated power exceeds 100% of
the monitoring limit.
[3]
Warning and trip
Activates both of the above, including warning, trip and alarm.
If power monitoring is set to
Off
[0] or
Warning
[1], 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%).
2 Parameter Description
VLT
®
AQUA Drive Programming Guide
48
MG.20.O4.02 - VLT
®
is a registered Danfoss trademark
2