HBM FIT 7A, Operating Manual

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Inputs and outputs
18
A03924_02_YI0_00 HBM: public
FIT
®
7A
Valve 1 Valve 2
Power
supply 1
Power
supply 2
Connector 1 Connector 2 Connector 1 Connector 2
Ub 1
GND 1
Ub 2
GND 2
FIT7A - 1 FIT7A - 2
OUTx OUTx
GND
connection
Fig. 7.1 GND potential and load circuit
Important
No GND potential is present at device socket 2, so you must connect the refer­
ence potential (GND) of the load circuits with GND at device socket 1.
There are two distinctive cases when connecting GND potential:
1. The arrangement of the function blocks, i.e. the digital part for the switch
outputs and the part for supplying with operating voltage and the interface,
is physically separate (
Fig. 7.2 ).
2. Both function blocks are inside a control cabinet ( Fig. 7.3 ).
In the first case, make sure that the shields of both leads, as well as the GND
potential, are each connected with a wire with a minimum cross-section of
1.5 mm
2
. However, the individual leads must not take different routes, they
must be close together and of the same length. The total length of a conductor
must not exceed 10 m (
Fig. 7.2 ).