Siemens MICROMASTER 420 - Page 126

3 Functions Issue 07/04
MICROMASTER 420 Operating Instructions
126 6SE6400-5AA00-0BP0
WARNING
 For compound braking, regenerative braking is superimposed on the DC
braking (braking along a ramp). This means that components of the kinetic
energy of the motor and driven load are converted into thermal energy in the
motor. If this power loss is too high or if the braking operation takes too long,
then this can cause the drive to overheat !
 When using compound braking it must be expected that there is a higher level
of noise above the compound braking switch-in threshold.
NOTE
 Compound braking is de-activated, if
- flying restart is active, and
- DC braking is active is selected.
 The compound switch-in threshold V
DC-Comp
is dependent on P1254
V
DC-Comp
(P1254 = 0) ≠ V
DC-Comp
(P1254 ≠ 0)
a) Auto-detect circuit enabled (P1254 = 1):
- V
DC-Comp
(P1254 = 1) is automatically calculated when the drive inverter
runs-up - i.e. after the line supply voltage has been connected
- Using the auto-detect function, the V
DC-Comp
threshold automatically
adapts itself to the line supply voltage at the particular installation
location.
b) Auto-detect function disabled (P1254 = 0):
-
0210213.1, PV CompDC ⋅⋅=
- The V
DC-Comp
threshold is immediately re-calculated after entering P0210
- P0210 must be adapted to the particular installation location