Start-up
11.98
4-2
ENGLISH
Siemens AG 6SE7087-6AC85-0AA0
Common Rectifier Operating instructions
WARNING
The rated ac-side voltage setting on the switch S1 must correspond exactly with the
voltage set on the connected converters, thus guaranteeing the correct sequence of
bypassing and load current extraction.
If the rated ac-side voltage is set too high, the end of precharging is not reached when one
of the connected converter is tapping load current adequately. Consequently, the
precharging resistors get overheated and the unit switches off with a 'Fault' signal. The
bypassing relays also open too early in the event of mains voltage drops and may be
damaged by dc arcs.
If the rated ac-side voltage is set too low, the precharging resistors are bypassed too early
and an overcurrent pulse occurs which may lead to damaging of the rectifier, the relay
contacts and the fuses.
When using parallel converters, it is imperative to connect the positive and negative poles
(C/L+ and D/L-) of the dc link correctly because its freewheeling diodes are not adequately
protected against excess currents by the fuses of the common rectifier.
Operation without a main contactor or a similarly functioning device that isolates the unit
from the mains when the 'Fault' contact opens is not permissible and may lead to
damaging of the unit.
To prevent unexpected activation after malfunctions, it is necessary to wire a latching
circuit for the main contactor.
A voltage must be selected with switches S1 or S3 as otherwise the fuse will drop out.
Precharging begins as from the point when the mains voltage is applied and is ended by bridging of the
precharging resistors when U
d
exceeds the On threshold.
When U
d
falls below the Off threshold, bridging of the precharging resistors is ended and the unit is again in the
precharging state.
Rated voltage U
n
chained in V
rms
(A.C.)
Rated values of DC-link
voltage U
nd
in V= at rated load
(set parameter P071 on the
SIMOVERT Master Drive)
On threshold
of U
d
in V=
Off threshold
of U
d
in V=
460 605
508 419
440 578
486 400
415 545
458 378
400 526
442 364
380 500
420 346
230 302
254 209
200 263
220 181
Table 4.1
On and off thresholds for units 6SE70xx-xEx8x
www
. ElectricalPartManuals
. com
