Dc Braking - Danfoss VT2800 Series Design Manual

123 Min. frequency for activation of
function at stop
(MIN.F.FUNC.STOP)
Value:
0,1 - 10 Hz
Function:
In this parameter, the output frequency is set at
which the function selected in parameter 122
Function at stop is to be acti v ated.
Description of choice:
Set the required output frequency.
NB!:
If parameter 123 is set higher than parameter
130, then the start delay function (parameter
120 and 121) will be skipped.
NB!:
If parameter 123 is set too high, and DC
hold has been chosen in parameter 122,
the output frequency will jump to the value
in parameter 123 without ramping up. This may
cause an overcurrent warning / alarm.

DC Braking

During DC braking DC voltage is supplied to the
motor, and this will cause the shaft to be brought to
a standstill. In parameter 132 DC brake voltage DC
brake voltage can be preset from 0-100%. Max. DC
brake voltage depends on the motor data selected.
In parameter 126 DC braking time DC braking time
is determined and in parameter 127 DC brake cut-in
frequency the frequency at which DC braking becomes
acti v e is selected. If a digital input is programmed to DC
braking inverse [5] and shifts from logic '1' to logic '0',
DC braking will be acti v ated. When a stop command
becomes acti v e, DC braking is acti v ated when the
output frequency is less than the brake cut-in frequency.
NB!:
DC braking may not be used if the inertia in
the motor shaft is more than 20 times greater
than the motor's internal inertia.
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.E9.02 - VLT is a registered Danfoss trademark
126 DC brake time
(DC BRAKING TIME)
Value:
0 - 60 sec.
0,1 Hz
Function:
In this parameter, the DC brake time is set at which
parameter 132 DC brake voltage is to be acti v e.
Description of choice:
Set the required time.
127 DC brake cut-in frequency
(DC BRAKE CUT-IN)
Value:
0.0 (OFF) - par. 202
Output frequency high limit, f
Function:
In this parameter, the DC brake cut-in frequency
is set at which the DC brake is to be acti v ated
in connection with a stop command.
Description of choice:
Set the required frequency.
128 Thermal motor protection
(MOT.THERM PROTEC)
Value:
No protection (NO PROTECTION)
Thermistor warning
(THERMISTOR WARN)
Thermistor trip (THERMISTOR TRIP)
ETR warning 1 (ETR WARNING 1)
ETR trip 1 (ETR TRIP 1)
ETR warning 2 (ETR WARNING 2)
ETR trip 2 (ETR TRIP 2)
ETR warning 3 (ETR WARNING 3)
ETR trip 3 (ETR TRIP 3)
ETR warning 4 (ETR WARNING 4)
ETR trip 4 (ETR TRIP 4)
Function:
The frequency converter can monitor the motor
temperature in two different ways:
- Via a PTC thermistor that is mounted on the motor.
The thermistor is connected between terminal 50
(+10V) and one of the digital input terminals 18, 19,
27 or 29. See parameter 300 Digital inputs.
®
VLT 2800 Series
MAX
10 sec
OFF
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