VEGA 3041 User Manual
Operating Instruction
Ex-separator type 3041
5 6 7 8
MTL 3000 Series
MEASUREMENT TECHNOLOGY LTD.
Level and Pressure
125mA
FUSE
1 2 3 4
out
in
Application and function
Ex-separator type 3041 for intrinsically safe power
supply of two-wire transmitters in Ex-areas.
Transmitters such as e.g. VEGABAR and VEGADIF,
with a current output of 4 … 20 mA, are used in
conjunction with the separator in Ex-areas. The
separator separates Ex-areas from not-Ex-areas,
meets Ex ia IIC and is characterized by three general
functions:
- intrinsically safe power supply of a two-wire
transmitter in Ex-areas
- transmission of the 4 … 20 mA current signal
- galvanic isolation of the three circuits (power
supply, converter and output circuit).
The power supply of 20 … 35 V DC is connected to
terminals 3 and 4..
Operating instruction
This current signal in the trnasmitter circuit is
transmitted floating by the separator via terminals 1
and 2 to the connected signal conditioning instrument.
Due to the complete galvanic isolation of the three
circuits, the circuits can be earthed at one end to the
earth potential in any position. Problems in the signal
transmission to processing systems by earthing
problems and current loss are thereofre solved.
„Intrinsically safe“ identifies a protection by which
current and voltage of a circuit are limited such that
the energy released in case of shortcircuits and
switching procedures is not sufficient to ignite explosive mixtures.
On terminals 5 and 6 the separator delivers an
intrinsically safe, floating DC voltage to power a twowire transmitter. The transmitter converts a parameter,
e.g. a pressure into a 4 ... 20 mA current signal proportional to the parameter.
Transmitters
(Sensors)
Technical data and dimensions
Power supply (terminals 3 and 4)
Voltage 20 … 35 V DC
Power consumption max. 2,8 W
Current consumption max. 125 mA
Transmitter circuit (Ex-area, terminal 5 and 6)
Signal transmission range 4 … 20 mA
Characteristic for intrinsic safety (Ex ia IIC) U
No-load voltage 28 V
Full load voltage 17,5 V
Line impedance max. in Ohm Z
Output circuit (Not-Ex-area, terminal 1 and 2)
Signal transmission areas 4 … 20 mA
Inner resistor > 1 MΩ
Load resistor max. 800 Ω
Linearity error at 20°C < 20 µA
Temperature drift < 1 µA/°C
Residual ripple < 10 µA peak – peak
= 28 V; I
max
R
≥ 300 Ω; PK ≤ 2,6 W
I
17,5 V – (min. transmitter operating voltage)
= ––––––––––––––––––––––––––––––––––––––––––––
max
p
≤ 93 mA
K
0,023 A
out
in
Signal
conditioning
instrument
2 Ex-separator type 3041
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