144 Gain Ac Brake - Danfoss VLT 2800 Series Operating Instructions Manual

Function:
This parameter can be set so that the internal fan is
automatically switched on and off. You can also set
the internal fan to be permanently switched on or off.
Description of choice:
If Automatic [0] are selected, the internal fan is
switched on or off depending on the ambient tem-
perature and the loading of the frequency converter.
If Always switched on [1] Always switched off [2] is
selected, the internal fan will be permanently
switched on or off.
NB!:
If Always switched off [2] is selected in combi-
nation with high switch frequency, long motor
cables or high output power, the frequency con-
verter's life span is reduced.

144 Gain AC brake

144
(GAIN AC BRAKE)
Value:
1.00 - 1.50
Function:
This parameter is used to set the AC brake. Using
par. 144 it is possible to adjust the size of the gener-
ator torque that can be applied to the motor without
the intermediate circuit voltage exceeding the warn-
ing level.
Description of choice:
The value is increased if a greater possible brake
torque is required. If 1.0 is selected, this corre-
sponds to the AC brake being inactive.
NB!:
If the value in par. 144 is increased, the
motor current will simultaneously increase sig-
nificantly when generator loads are applied. The
parameter should therefore only be changed if it is
guaranteed during measurement that the motor cur-
rent in all operating situations will never exceed the
maximum permitted current in the motor. Please
note: that the current cannot be read out from the
display.
146 Reset voltage vector
146
(RESET VECTOR)
Value:
*Off (OFF)
Reset (RESET)
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.A5.02 - VLT is a registered Danfoss trade mark
®
VLT 2800 Series
Function:
When the voltage vector is reset it is set to the same
starting point each time a new process commences.
Description of choice:
Select reset (1) when running unique processes
each time they arise. This will enable repetitive pre-
cision when stopping to be improved. Select Off (0)
for example for lifting/lowering operations or syn-
chronous motors. It is an advantage that the motor
and the frequency converter are always synchro-
nised.
1.30
[0]
[1]
23