Connecting To Voltage Supply; Preparing The Connection - Vega VEGAMET 381 Ex Instrucción De Servicio

Connecting to voltage supply

Fig. 11: Wall mounting
1 Metal strap
2 Covering slide switch active-passive
Front panel mounting
1 Remove the pluggable terminal strips from the
top and bottom.
2 Screw pin [3] into the rear of VEGAMET 381 Ex
and tighten with a screwdriver.
3 Insert VEGAMET 381 Ex from the front into the
front panel [1].
4 Place the clamping strap [2] from the back over
the pin [3] and pull it with the knurled nut [4]
against the panel [1].
1
2
~90
Fig. 12: Front panel mounting
1 Front panel
2 Terminal strap
3 Pin
4 Knurled nut
22
1
80
92
3 4
5 Connecting to voltage
supply
2

5.1 Preparing the connection

Note safety instructions
Generally note the following safety instructions:
Connect only in the complete absence of line
l
voltage
If overvoltage surges are expected, overvolt-
l
age arresters should be installed
Tip:
We recommend VEGA overvoltage arrest-
ers B61-300 (power supply VEGAMET 381
Ex) and B62-36G (sensor supply).Take
note of safety instructions for Ex applications
In hazardous areas you should take note of
the appropriate regulations, conformity and
type approval certificates of the sensors
and power supply units.Select power
supply
The power supply can be 20 ... 253 V AC, 50/60 Hz
or 20 ... 253 V DC.
Selecting connection cable
Power supply of VEGAMET 381 Ex is connected
with standard cable according to the national
installation standards.
Standard two-wire cable without screening can be
used to connect sensors. If electromagnetic inter-
ference is expected, screened cable must be used.
Cable screening and grounding
Connect the cable screen on both ends to ground
potential. In the sensor, the screen must be
connected directly to the internal ground terminal.
The ground terminal outside on the sensor housing
must be connected to the potential equalisation.
If potential equalisation currents are expected, the
screen connection on the side of VEGAMET 381
Ex must be made via a ceramic capacitor (e.g. 1 nF,
1500 V). The low frequency potential equalisation
currents are thus suppressed, but the protective
effect against high frequency interference signals
remains.
VEGAMET 381 Ex