VEGA VEGABAR 20 - Manual (Page 11)

VEGABAR 20 11
Mounting, electrical connection
2 Mounting
VEGABAR can be mounted in any position.
Cable entries must point downwards to avoid
humidity ingress. For this purpose the hous-
ing can be rotated by 330° in relation to the
mounting part.
A seal, appropriate for the connection, must
be used for mounting. This seal is either
supplied with VEGABAR or must be provided
by the customer.
Compensation of the atmospheric
pressure
The atmospheric pressure of instruments
used for overpressure measurements is
compensated via a breather facility inte-
grated in the housing.
3 Electrical connection
3.1 Connection information
The electronics in VEGABAR 20 require a
power supply of 12 … 36 V DC. It is pro-
vided in two-wire technology, i.e. supply
voltage and current signal are led to the
terminals via the same two-wire connection
cable.
This external energy is provided via a sepa-
rate power supply unit:
- power supply unit, e.g. VEGASTAB 690
- processing unit with integral DC-current
source (e.g. active PLC-input)
- VEGAMET or VEGADIS 371
Note that the external energy source is reli-
ably separated from the mains circuits acc.
to DIN VDE 0106, part 101. The above-men-
tioned VEGA-instruments meet this require-
ment, and protection class III is therefore
ensured.
The external energy source must supply a
terminal voltage of at least 12 V to the trans-
mitter. The actual terminal voltage on the
transmitter depends on the following factors:
- output voltage of the external energy
source under nominal load,
- electrical resistors of the connected instru-
ments in the circuit (see connected instru-
ments, load resistor).
Note the following instructions for electrical
connection:
- Connection must be made acc. to the spe-
cific installation standards (e.g. in Germany
according to the VDE-regulations).
- Terminal voltage must not exceed 36 V to
avoid damage to the electronics.
- Electrical connection is provided with re-
verse polarity protection.
- The wiring between VEGABAR and the
power supply can be carried out using
standard two-wire cable.