BU 0750 GB
Technical design subject to change
83
Parameter
Setting value / Description / Note
Parameter
set
Available with option
P107
Brake reaction time
P
Always available
0 ... 2.50 s
[ 0.00 ]
For physical reasons electromagnetic brakes take a certain amount of time before responding. As a
result load sagging may occur in lifting gear applications because there is a delay before brake ac-
tion applies to the load as well.
This kind of delayed action can be taken into account by providing a suitable setting of parameter
P107 (brake control).
During the brake reaction time which is adjustable as required the frequency inverter will supply the
absolute minimum frequency set in P505. As a result the motor will not start up against the brake
and loads will not sag when the motor stops.
For this aspect see also the >Lifting time< parameter P114.
Notes:
We recommend that (especially with hoisting gear) an internal relay be used for
electromagnetic brake control (P434/441 function 1, external brake). Besides
do not select an absolute minimum frequency less than 2.0 Hz (P505).
Setting example:
hoisting gear with brake
P114 = 0.2 sec.
P107 = 0.2 sec.
P201…P208 = motor data
P434 = 1 (ext. brake)
P505 = 2...4Hz
For sure ramp-up speed
P112 = 402 (Aus)
P536 = 2.1 (Aus)
P537 = 0 (Aus)
P539 = 2/3 (I
SD
observation)
against load sagging
P214 = 50...100% (preset)
Output frequency
P107
brake is lifted
P114
or
P107, if P114 = 0
ON signal
P505
OFF signal
time
Note:
After a brake release time has been set (P107 / P114), the brake will not be controlled until
at least ¼ of the rated magnetization current (P209) is flowing. The static boost will be taken
into account accordingly if the values are < 100%.
