Vega VEGABAR 51, Руководство по эксплуатации

Страница: 19 / 80

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 ). L ow -
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 equalisation
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 of the cable mantle , strip approx .
1
cm
insulation from 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
8
P ress down the opening levers of the terminals , you will hear the
terminal spring closing
9
C
heck the hold of the wires in the terminals by lightly pulling on
them
10
C
onnect the screen to the internal ground terminal
,
connect the
outer ground terminal to potential equalisation
11
T ighten the compression nut of the cable entry . T he seal ring must
completely encircle the cable
12
S crew the housing cover on
S ingle / D ouble chamber
housing
VEGABAR
51
• F
oundation
F
ieldbus
19
5
C
onnecting to power supply
36715
-
EN
-
110629