Vega VEGABAR 17, Руководство по эксплуатации

Страница: 13 / 36

C
onnect the cable screen on both ends to ground potential
.
I
f potential equalisation currents are expected
,
the connection on the
processing side must be made 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 interfer
-
ence signals remains
.
W
arning
:
C
onsiderable potential di
ff
erences exist inside galvanic plants as well
as vessels with cathodic corrosion protection
. V
ery large equalisation
currents can
fl
ow through the cable screen when the screen is
grounded on both ends
. T
o avoid this
,
the cable screen must be
connected to ground potential only on one end
(
inside the switching
cabinet
)
in such applications
. T
he cable screen must
not
be
connected to the internal ground terminal in the sensor and the outer
ground terminal on the housing
not
to potential equalisation
!
I nformation :
T
he metallic parts of the instrument
(
antenna
,
transmitter
,
concentric
tube
,
etc
.)
are conductively connected with the inner and outer ground
terminal on the housing
. T
his connection exists either as a direct
metallic contact or via the shielding of the special connection cable on
instruments with external electronics
. Y
ou can
fi
nd speci
fi
cations on
the potential connections within the instrument in chapter
" T echnical
data " .
T
ake note of the corresponding installation regulations for
E
x
applications
.
5
.
2
C
onnection procedure
P
roceed as follows
:
1
L
oosen the screw on the rear of the plug connector
2
R
emove the plug connector and seal from
VEGABAR
17
3
R
emove the plug insert from the plug housing
C able screening and
grounding
S
elect connec
-
tion cable for
E
x
applications
C onnection via angle
plug connector
VEGABAR
17 13
5
C
onnecting to power supply
27636
-
EN
-
120531