VEGA VEGAPULS 54K enamel - Manual (Page 27)

VEGAPULS 54K enamel 27
24 101-EN-041227
Electrical connection
VEGAPULS 54K Ex with pressure-tight encapsulated connection
compartment in four-wire technology
• Four-wire technology, supply and output signal via two separate two-wire cables for opera-
tion in Ex-Zone 1 (VEGAPULS …K Ex) or Ex-Zone 0 (VEGAPULS …K 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
- +
4 … 20 mA
2
2
2
4
1)
250 Ω
EEx d ia
1) If the resistance of the processing systems
connected to the 4 … 20 mA signal output is less
than 200
Ω, a resistor must be connected to the
connection cable during adjustment to get a loop
resistance between 250
Ω up to 300 Ω.
The digital adjustment signal would otherwise be
severely damped or short-circuited due to
insufficient resistance of the connected process-
ing system. Digital communication with the PC or
the HART
® handheld would not be ensured.
VEGA-
CONNECT 2
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.