must be connected directly to the internal ground terminal
.
T
he
ground terminal outside on the housing must be connected to
the potential equalisation
(
low impedance
).
I
n systems without potential equalisation
,
connect the cable
screen directly to ground potential at the power supply unit and
at the sensor
.
I
n the connection box or
T
-
distributor
,
the screen
of the short stub to the sensor must not be connected to
ground potential or to another cable screen
.
T
he cable screens
to the power supply unit and to the next distributor must be
connected to each other and also connected to ground
potential via a ceramic capacitor
(
e
.
g
.
1
n
F
,
1500
V
).
T
he low
frequency potential equalisation currents are thus suppressed
,
but the protective e
ff
ect against high frequency interference
signals remains
.
T
he total capacitance of the cable and of all capacitors must
not exceed
10
n
F
in
E
x applications
.
T
ake note of the corresponding installation regulations for
E
x
applications
.
I
n particular
,
make sure that no potential equal
-
isation currents
fl
ow over the cable screen
.
I
n case of
grounding on both sides this can be achieved by the use of a
capacitor or a separate potential equalisation
.
5
.
2
C
onnection procedure
P
roceed as follows
:
1
U
nscrew the housing cover
2
I
f an indicating and adjustment module is installed
,
remove
it by turning it slightly to the left
.
3
L
oosen compression nut of the cable entry
4
R
emove approx
.
10
cm
(
4
in
)
of the cable mantle
,
strip
approx
.
1
cm
(
0
.
4
in
)
insulation from the ends of the
individual wires
5
I
nsert the cable into the sensor through the cable entry
6
L
ift the opening levers of the terminals with a screwdriver
(
see following illustration
)
7
I
nsert the wire ends into the open terminals according to
the wiring plan
S
elect connection
cable for
E
x applica
-
tions
14
VEGABAR
53
-
P
ro
fi
bus
PA
C
onnecting to power supply
28250
-
EN
-
051004