224 Carrier Frequency (Carrier Freq.); 230 Digital Speed Up/Down (Speed Up Down); 300 Brake Function (Brake Option); 306 Dc Braking Time (Dc-Brake Time) - Danfoss VLT 2000 Series Manual

224 Carrier frequency (CARRIER FREQ.)

Value:
2 - 16 kHz
Function:
To avoid or reduce motor noise you can increase or
reduce the carrier frequency of the frequency converter.
Description:
It is possible to change the carrier frequency between
2 and 16 kHz. The disadvantages of operating at a
high carrier frequency are:
− reduced continuous output current, see page 95.
− reduced efficiency.
− higher capacitive leakage current.
− increased RFI radiation from the VLT frequency
converter.
See also the derating curve on page 95.
The disadvantages of a too low carrier frequency are
a less ideal output current and motor loss.

230 Digital speed up/down (SPEED UP DOWN)

Value:
Disable (DISABLE)
Enable (ENABLE)
Enable and save (ENABLE+STORE)
Function:
Using this parameter you can make the VLT
frequency converter lock the output frequency to the
latest indicated speed reference.
Description:
You can choose to have either digital speed up/down
(terminal 18/27 and 19) or other speed references.
When you have chosen Enable you must choose
Speed up (terminal 18) and Speed down (terminal 19)
in parameters 402/404 and 403.
When Enable and save is selected a speed will be
saved automatically after 15 seconds so that the unit
remembers this frequency after new start-up.
The other references will not be active so that the di-
gital references cannot be combined with other
references.
= Factory setting. Text in ( ) = Display text. The figures in [ ] are used in bus communication.
70
VLT

300 Brake function (BRAKE OPTION)

Value:
4.5 kHz
Function:
Using this parameter you can inform the VLT
frequency converter that a brake function and a brake
resistor have been connected. For information on
sizing, see page 30.
Description:
Choose Applied if you use a brake function and a
brake resistor.

306 DC braking time (DC-BRAKE TIME)

Value:
Function:
Using this parameter you can record how long the DC
braking must be active.
Description:
When you choose the braking time you must consider
[0]
[1] if you want to maintain the braking torque or if you
[2] want to use a stop function.
The DC braking time must be ≠ 0 to activate DC
braking.
307 DC-brake cut-in frequency (DC-BRK ON FREQ)
Value:
Function:
Using this parameter you can record the output fre-
quency at which DC braking must start when ramping
down to standstill.
Description:
The cut-in frequency depends on the application. The
cut-in frequency must be > 0 to activate DC braking.
Instead of using this parameter you can activate DC
braking via terminal 27 if a DC braking time and a DC
brake voltage have been recorded.
® 2000 Series
Not applied (NOT APPLIED)
Applied (APPLIED)
0 - 60 sec. 0 sec.
0 - 500 Hz 1 Hz
MG.20.B6.02 – VLT is a registered Danfoss trademark
[0]
[1]