VEGA VEGAPULS 41 4 … 20 mA; HART compact sensor - Manual (Page 39)

VEGAPULS 41 – 4 … 20 mA 39
26620-EN-041227
Electrical connection
VEGAPULS 41 Ex with pressure-tight encapsulated connection
compartment in four-wire technology (Ex d)
• Four-wire technology, supply and output signal via two separate two-wire cables for opera-
tion in Ex-Zone 1 (VEGAPULS …Ex) or Ex-Zone 0 (VEGAPULS …Ex0).
• Output signal 4 … 20 mA (active).
• Optional external indicating instrument with analogue and digital display (can be mounted
up to 25 m away from the sensor in Ex area).
• Adjustment with PC, HART ® handheld or adjustment module MINICOM (can be plugged into
the sensor or into the external indicating instrument VEGADIS 50).
• Load max. 500
Ω.
2
2
4
2
2
- +
4 … 20mA
> 250
Ω
1) If the resistance of the processing systems
connected to the 4 … 20 mA signal output is less
than 250
Ω, a resistor must be connected to the
connection cable during adjustment to get a loop
resistance between 250
Ω.
The digital adjustment signal would otherwise be
severely damped or short-circuited due to
insufficient resistance of the connected
processing system. Digital communication with the
PC or the HART
® handheld would not be ensured.
VEGA-
CONNECT
VEGADIS 50 Ex
Ex area
active 2)
HART ® handheld
Non Ex area
2) 4 … 20 mA active means that the sensor delivers
a level-dependent current of 4 … 20 mA (source).
The measuring signal of the sensor reacts
electrically to the processing system (e.g. display)
like a current source.