Parameters: 2-** Brakes - Danfoss VLT Midi Drive FC 280 Programming Manual

Parameter Descriptions

4.3 Parameters: 2-** Brakes

2-00 DC Hold/Motor Preheat Current
Range: Function:
50 % [0 - Set the holding current as a percentage of the
160 %] rated motor current I
*
Current. This parameter holds the motor function
(holding torque) or pre-heats the motor. This
parameter is active if [0] DC hold is selected in
parameter 1-72 Start Function, or if [1] DC hold/pre-
heat is selected in parameter 1-80 Function at
Stop.
NOTICE
The maximum value depends on the rated
motor current. Avoid 100% current for too
long. It may damage the motor.
2-01 DC Brake Current
Range: Function:
NOTICE
50 [0 -
% 150 %
*
MOTOR OVERHEATING
]
The maximum value depends on the rated
motor current.
To avoid motor damage caused by
overheating, do not run at 100% for too
long.
Set current as % of rated motor current,
parameter 1-24 Motor Current. When speed is
below the limit set in parameter 2-04 DC Brake Cut
In Speed, or when the DC-brake inverse function is
active (in parameter group 5-1* Digital Inputs set to
[5] DC-brake inverse; or via the serial port), a DC-
brake current is applied on a stop command. See
parameter 2-02 DC Braking Time for duration.
2-02 DC Braking Time
Range: Function:
10 s [0 - 60 s] Set the duration of the DC-brake current set in
*
parameter 2-01 DC Brake Current, once
activated.
2-04 DC Brake Cut In Speed
Range: Function:
0 Hz [ 0 - 500 This parameter is for setting the DC brake
*
Hz] cut-in speed at which the DC brake current
parameter 2-01 DC Brake Current is to be
active, with a stop command.
2-06 Parking Current
Range: Function:
100 % [0 - 150 %] Set current as percentage of rated motor
*
current, parameter 1-24 Motor Current.
MG07C302
Programming Guide
parameter 1-24 Motor
M,N
Danfoss A/S © 07/2016 All rights reserved.
2-07 Parking Time
Range: Function:
3 s [0.1 - 60 s] Set the duration of the parking current set in
*
parameter 2-06 Parking Current, once activated.
2-10 Brake Function
Option: Function:
[0] Off No brake resistor is installed.
*
[1] Resistor A brake resistor is incorporated in the system for
brake dissipating surplus brake energy as heat.
Connecting a brake resistor allows a higher DC-
link voltage during braking (generating
operation). The brake resistor function is only
active in frequency converters with an integral
dynamic brake.
[2] AC brake Improve braking without using a brake resistor.
This parameter controls an overmagnetization 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 braking
torque without exceeding the voltage limit.
NOTICE
The AC brake is not as efficient as
dynamic braking with resistor.
AC brake is for VVC
and closed loop.
2-11 Brake Resistor (ohm)
Range: Function:
Set the brake resistor value in Ω. This
Size [ 0 -
related 65535 value is used for monitoring the power to
*
Ohm] the brake resistor. Parameter 2-11 Brake
Resistor (ohm) is only active in frequency
converters with an integral dynamic brake.
Use this parameter for values without
decimals.
2-12 Brake Power Limit (kW)
Range: Function:
Size [0.001 - Parameter 2-12 Brake Power Limit (kW) is the
related 2000 expected average power dissipated in the
*
kW] 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.
U
P W =
br, avg R
br
+ mode in both open
2
V × t s
br br
Ω × T s
br
41
4 4