Bosch Rexroth Servodyn-D Series, Руководство по обслуживанию, Страница: 18 / 74

Electric Drives
and Controls
2–3 Bosch Rexroth AG Servodyn-D 1070 066 032 / 03
Mains connection at the place of installation
2.2 Earth-leakage circuit-breaker
Inverters incorporate switched power units which are always associated
with capacitive leakage currents against earth. The leakage currents
may depend on the number of inverters, the earthing conditions as well
as the design and length of motor power cables.
Mains filters and shielded cables used to improve the electromagnetic
compatibility (EMC) increase the leakage currents further. For this rea-
son, no earth-leakage circuit-breakers with nominal leakage currents of
less than 300 mA may be used.
DANGEROUS ELECTRICAL VOLTAGE
Personnel protection is only guaranteed if earth-leakage circuit-
breakers with nominal leakage currents of less than 30 mA are
used.
.
Inductors and/or capacitors present in the electric circuit may lead
to spurious trips. If radio interference suppression filters are used,
spurious trips can only be avoided by installing an isolating trans-
former.
DANGEROUS ELECTRICAL VOLTAGE
If a pulse power current sensitive e.l.c.b. type A in accordance with
IEC-755 (VDE 0664) is used, its protective function is not guaran-
teed for inverters with a 3-phase mains connection (B6 circuit).
The protection of all electrical components connected together with in-
verters with a 3-phase mains connection to a pulse power current sensi-
tive e.l.c.b. may be adversely affected.
Therefore, you should either install an isolating transformer with a pro-
tective device and earthing in the mains feeder, or use a universal cur-
rent sensitive e.l.c.b. type B which also provides safety disconnection in
the event of DC leakage currents.