Technical data
j
| BA 14.0197 | 11/2010
18
Engagement time
Short brake engagement times are vital for emergency braking. DC switching together with
a suitable spark suppressor must therefore be provided.
If the drive system includes a frequency inverter so that the brake is deenergised only when
the motor is at standstill, switching on the AC side is also possible (not valid for emergency
braking). In this case, engagement times will be approx. 5 times longer, connection
3.4
Operating frequency / friction work
BFK464−XX−S−001.iso/dms
Fig. 3
Friction work as a function of the operating frequency
S
fperm
+
*
S
tf
ln
ǒ
1
*
Q
Q
E
Ǔ
Q
perm
+
Q
E
ǒ
1
*
e
*
Stf
Sf
Ǔ
The permissible operating frequency "S
hperm
" depends on the friction work "Q" (see Fig. 3).
An operating frequency of "S
h
" results in the permissible friction work "Q
perm
".
With high speed and friction work, the wear increases strongly, because very high
temperatures occur at the friction faces for a short time.
