GE VersaPoint IC220PBI002, User Manual

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GFK-1911B Chapter 5 Power for the Station 5-7
5
Segment 1 The NIU supply and the main supply U
M
are supplied at
the NIU (1).
The supply voltage of the logic U
L
and the supply voltage
of the analog modules U
ANA
are generated from the NIU
supply (U
L
and U
ANA
are not considered in the figure).
Electrical isolation between logic and I/O is given
through the separate supply of the NIU and U
M
. The
segment supply U
S
for segment 1 is tapped from the
main supply U
M
. In this case, this happens through a
switch located at the corresponding terminal points of
the bus module. The digital output modules (2 and 3) are
located in a switched segment circuit.
As the two output modules consume a maximum of 8A,
the main voltage U
M
must be reinjected behind these
two modules to prevent the current carrying capacity of
the voltage jumpers from being exceeded.
Segment 2 The supply voltage U
M
is reinjected at the power terminal
(4).
Using a jumper, the segment voltage U
S
for segment 2
is tapped at this module from the main voltage U
M
.
Segment 3 Segment 3 is created though a segment terminal with
fuse (7).
In a segment terminal with fuse the segment voltage is
automatically tapped from the main voltage. This
segment circuit is protected by an internal fuse. Because
of this fuse the circuit is suitable for the connection of
input terminals without internal fusing (8 and 9) or for the
connection of output terminals (not present in this
example).
Segment Circuits have the advantage of isolating errors
In this example, a short circuit in input module 8 would not affect the modules
of the first or second segment. Because of the fuse in segment terminal 7,
only the third segment is switched off.
If an error occurred in the system, the discrete output modules 2 and 3 could
be switched on or off without affecting modules of other segments.