Danfoss VLT AutomationDrive FC 300 Programming Manual page 67

3 Parameter descriptions
3.4.3 2-1* Brake Energy Funct.
Parameter group for selecting dynamic braking parameters. Only valid for drives with brake chopper.
2-10 Brake Function
Option:
[0] * Off
3
[1] Resistor brake
[2] AC brake
2-11 Brake Resistor (ohm)
Range:
Application [Application dependant]
dependent*
2-12 Brake Power Limit (kW)
Range:
Application [Application dependant]
dependent*
For 200 - 240 V units:
For 380 - 480 V units
For 380 - 500 V units
For 575 - 600 V units
This parameter is only active in frequency converters with an integral dynamic brake.
2-13 Brake Power Monitoring
Option:
[0] * Off
[1] Warning
66
Function:
No brake resistor is installed.
A brake resistor is incorporated in the system, for dissipation of surplus brake energy as heat. Con-
necting 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.
Is selected to improve braking without using a brake resistor. This parameter controls an overmag-
netization of the motor when running with a generatoric load. This function can improve the OVC-
function. Increasing the electrical losses in the motor allows the OVC function to increase the braking
torque without exceeding the over voltage limit. Please note that AC brake is not as effective as
dynamic breaking with resistor.
AC brake is for VVC + and flux mode in both open and closed loop.
Function:
Set the brake resistor value in Ohms. This value is used for monitoring the power to the brake
resistor in par. 2-13 Brake Power Monitoring
with an integral dynamic brake.
Use this parameter for values without decimals. For a selection with two decimals, use
Brake Resistor (ohm)
par. 30-81
Function:
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.
390 2 ×
dutytime
P resistor
=
[W]
R
× 120
778 2 ×
dutytime
P resistor
=
[W]
R × 120
810 2 ×
dutytime
P resistor
=
[W]
R
× 120
943 2 ×
dutytime
P resistor
=
[W]
R
× 120
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
duty time.
No brake power monitoring required.
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.
MG.33.M8.02 - VLT
. This parameter is only active in frequency converters
.
Brake Resistor (ohm)
), the DC link voltage, and the resistor
Brake Power Limit (kW) ).
®
is a registered Danfoss trademark
FC 300 Programming Guide