Operating instructions

15
For optimum adjustment to different products and production processes as well as differently
electrical loads, the most favorable operating and control modes may be set according to the
following overview.
2.1 OPERATING MODES
This chapter gives an overview of the different operating modes.
FULL WAVE SWITCH (TAKT)
Depending on the prescribed set point, the
mains voltage is periodically switched. In this
operating mode, almost no harmonics are
created. Whole multiples of the mains peri-
ods are switched. The operating mode „full
wave switch“ is especially suited for loads with
thermal inertia. For mains load optimization the
optional feature dASM or the optional ASM
feature (not for new installations) can be used
with this operating mode.
For operating mode TAKT, also SSSD ramp can be used. This is useful in case of switching on a
transformer. The SSSD ramp will only be used once after reset or impulse inhibit.
Key parameters are
TAKT cycle period T
0
[sec]
Soft-Start SST [msec]
Soft-Down SDN [msec]
PHASE-ANGLE FIRING (VAR, WITH 1P AND 3P)
Depending on the prescribed set point, the sine oscillation of the mains voltage is gated using a
larger or smaller control angle a. This operating mode is characterized by high control dynamics.
In operating mode phase-angle firing, it is possible to compensate harmonics of the mains voltage
by using circuit variants (e.g. vector group transformer).
To prevent sudden changes of modulation, SSSD feature can be used. It works as a restrictor for
peaks.
Key parameters are
Soft-Start SST [msec]
Soft-Down SDN [msec]
2. FUNCTIONS