Siemens SENTRON - Configuration

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Notes on installation and use
5.3.3 Configuration
Type B / Type B+ universal current-sensitive residual current protective devices
must be used if smooth or nearly smooth DC residual currents can occur in the
event of a fault when electronic equipment is operated (input circuits 8 to 13 in
table 2).
In these cases, Type AC, A or F residual current protective devices may not be used
to provide protection, as their tripping function can be impaired by the potential
smooth DC residual currents to the extent that they are no longer able to trip even
when those residual currents for which they are designed occur.
For this reason, it is essential to ensure that if Type A or F residual current pro-
tective devices are coordinated with Type B (or B+) in installations with several
load circuits, a Type B or B+ residual current protective device is always connected
upstream of each Type A or Type F residual current protective device. Figure 23
shows an example conguration.
S
n
n
n
≥
≤
≥
I2_13610a
Type
AC/A
300 mA
Type
AC/A
100 mA
Type
B/B+
30 m
A
Wh
230/400 V AC,
3-phase
.+]
Wh
Type
AC/A
n
300 mA
Type
AC/A
n
100 mA
Type
n
30 m
A
≥
≤
≥
S
I2_13611a
230/400 V AC,
3-phase
B/B+
.+]
Figure 23: Conguration example with Type A and B residual current protective
devices