~90
92
1
3
2
4
F
ig
.
12
:
F
ront panel mounting
1
F
ront panel
2
T
erminal strap
3
P
in
4
K
nurled nut
5
C
onnecting to voltage
supply
5
.
1
P
reparing the connection
N
ote safety instructions
G
enerally note the following safety instructions
:
l
C
onnect only in the complete absence of line
voltage
l
I
f overvoltage surges are expected
,
overvolt
-
age arresters should be installed
T
ip
:
W
e recommend
VEGA
overvoltage arrest
-
ers
B
61
-
300
(
power supply
VEGAMET
381
)
and
B
62
-
36
G
(
sensor supply
).
T
ake note of
safety instructions for
E
x applications
I
n hazardous areas you should take note of
the appropriate regulations
,
conformity and
type approval certi
fi
cates of the sensors
and power supply units
.
S
elect power
supply
T
he power supply can be
20
…
253
V AC
,
50
/
60
H
z
or
20
…
253
V DC
.
S
electing connection cable
P
ower supply of
VEGAMET
381
is connected with
standard cable according to the national installation
standards
.
S
tandard two
-
wire cable without screening can be
used to connect sensors
.
I
f electromagnetic inter
-
ference is expected
,
screened cable must be used
.
C
able screening and grounding
C
onnect the cable screen on both ends to ground
potential
.
I
n the sensor
,
the screen must be
connected directly to the internal ground terminal
.
T
he ground terminal outside on the sensor housing
must be connected to the potential equalisation
.
I
f potential equalisation currents are expected
,
the
screen connection on the side of
VEGAMET
381
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 interference signals
remains
.
S
elect connection cable for
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
M
ount
VEGAMET
381
2
C
onnect sensor cable to terminal
1
and
2
,
and
where applicable
,
connect the screen
3
C
onnect power supply
(
switched o
ff
)
to termi
-
nal
5
and
6
4
I
f necessary
,
connect fail safe and operating
relay as well as current output
T
he electrical connection is
fi
nished
.
VEGAMET
381
21
C
onnecting to voltage supply
27567
-
01
-
070216
