Siemens SIMOVERT 6SE7024-1EB85-0AA0 Operating Instructions Manual page 80

Start-up
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
When U falls below the Off threshold, bridging of the precharging resistors is ended and the unit is again in the
d
precharging state.
Rated voltage U
n
chained in V (A.C.)
rms
460
440
415
400
380
230
200
Table 4.1 On and off thresholds for units 6SE70xx-xEx8x
4-2
ENGLISH
exceeds the On threshold.
d
Rated values of DC-link
voltage U in V= at rated load
nd
(set parameter P071 on the
SIMOVERT Master Drive)
605
578
545
526
500
302
263
WARNING
On threshold
of U in V=
d
508
486
458
442
420
254
220
Siemens AG
Common Rectifier
11.98
Off threshold
of U in V=
d
419
400
378
364
346
209
181
6SE7087-6AC85-0AA0
Operating instructions