VEGA VEGABAR 40 4 … 20 mA - Manual (Page 12)

12 VEGABAR 40 (4 … 20 mA)
Mounting, electrical connection
2 Mounting
2.1 Mounting instructions
VEGABAR can be mounted in any position.
Cable entries must point downwards to avoid
moisture ingress. For this purpose, the hous-
ing can be rotated by 330° in relation to the
mounting part.
A seal, appropriate for connection, must be
used for mounting. This seal is either sup-
plied with VEGABAR or must be provided by
the customer.
2.2 Compensation of the atmos-
pheric pressure
On instruments for gauge pressure meas-
urement, the atmospheric pressure is com-
pensated via a breather facility integrated in
the housing.
3 Electrical connection
3.1 Connection instructions
The electronics in VEGABAR 40 requires a
supply voltage 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 integrated DC current
source (e.g. active PLC input)
- VEGAMET or VEGADIS 371
Make sure that the external energy source is
reliably separated from the mains circuits
acc. to DIN VDE 0106, part 101. The above
mentioned VEGA instruments meet this re-
quirement, and protection class II 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 resistances of the connected
instruments in the circuit (see Connected
instruments, load resistor).