ic equipment for use in power installations). This is also specified in UL 508C
(Industrial Control Equipment) for North America. Housing cover or encapsu‐
lation by closed housing is used as protection against direct contact with live
conductors.
7.5.2
Protective Grounding
General Information
High contact voltage in case of error caused
by too long disconnecting time of mains cir‐
cuit breaker!
CAUTION
Select the mains circuit breaker such that the disconnecting time in the case
of error (short circuit or ground fault) is shorter than 5 s according to
EN 60204‑1 (Annex A.1).
Keep the fault loop impedance
of the electrical equipment (machine, instal‐
lation) as low as possible so that, in the case of error, the circuit breaker can
trigger within the specified disconnecting time.
Overcurrent protection normally is realized in the form of fuses or overcurrent
release devices (circuit breakers, motor circuit breakers) installed at the
mains connection. For details see figure.
Overcurrent protection generally is sized or set with a release current of
1.3 × nominal current of the loads connected to this connection point.
In the case of an insulation error or a connection between mains phase and
device housing connected to the equipment grounding conductor, the drive is
disconnected from the mains.
For dimensioning the fuses, comply with these data: See
15.3.4 "Mains Contactor and Fusing " on page 265
Fault loop impedance is the cumulative impedance from the current source via the
active conductors to the fault location and back to the current source via the equip‐
ment grounding conductor (see EN 60204‑1, Annex A.2). The fault loop impe‐
dance must be determined either by means of calculation or by means of meas‐
urement. Line lengths and the line cross sections have an influence on the fault
loop impedance.
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
Bosch Rexroth AG
85/309
Project Planning of Mains Connection
