VEGA VEGAPULS 45 4 … 20 mA; HART compact sensor - Manual (Page 39)

VEGAPULS 42, 44 and 45 – 4 … 20 mA 39
Electrical connection
2
2
4
2
- +
4 ... 20 mA
VEGADIS
371 Ex
Measuring system with VEGAPULS 42 or 44 on VEGADIS 371 Ex indicating
instrument with current and relay output (Ex ia)
• Two-wire technology (loop powered), intrinsically safe ia supply via the signal cable of the
VEGADIS 371 Ex indicating instrument for operation of the sensor in Ex zone 1 or Ex
zone 0.
• Optional external indicating instrument with analogue and digital display (can be mounted
up to 25 m away from the sensor).
• Adjustment with PC, HART ® handheld or adjustment module MINICOM (can be plugged into
the sensor or into the external indicating instrument VEGADIS 50).
(passive)
VEGADIS 50
0/4 … 20 mA
(active)
Relay
(see „7.2 Approvals“)
Ex area Non Ex area
HART ® handheld
VEGA-
CONNECT 2
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 of 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 would not be ensured.
1 )
Zone 0 or
Zone 1
EEx ia