VEGA VEGAPULS 51V…54V - Manual (Page 13)

VEGAPULS 51 V … 54 V 13
Types and versions - Configuration of meas. systems
2.2 Configuration of measuring
systems
Which radar sensor you use depends on
your process requirements and installation
conditions as well as on the requirements of
your control or processing system.
On sensors with digital output signal like
VEGAPULS 51 V … 54 V a meas. system
consists of a sensor and a processing unit.
The processing unit (the signal conditioning
instrument VEGAMET or the processing
system VEGALOG) evaluates the level pro-
portional digital meas. signal in a number of
routines and provides then the levels as
individual current, voltage or switching
signals.
On the following pages you find the various
instrument configurations which are called in
the following meas. system and which are
partly shown with a signal processing.
• 2 sensors on one two-wire line
(page 14)
• 2 sensors in Ex on one two-wire line
(page 15)
• 15 sensors on one two-wire line
(page 16)
• 3 sensors in Ex on one two-wire line
(page 17)
Ex
Series 50 sensors require for operation in Ex-
areas Ex-separator VEGATRENN 548 V Ex,
providing intrinsically safe Ex-circuits to the
sensors.
On the Ex-separtor VEGATRENN 548 V up to
9 sensors can be connected in groups with
three sensors each (see page 17).
Note to page 15…17:
2) Sensor lines should be looped in screened cables.
It is recommended to earth the cable screens on
both ends. However it must be noted that no earth
compensation currents flow over the screen. Earth
compensation currents are avoided in case of
earthing on both ends by connecting the cable
screen on one earth side (e.g. in the switching
cabinet) via a capacitor (e.g. 1 µF; 100 V) with the
earth potential.
Sensor lines leading to the same separator card,
can be looped together in one screened multiple
wire cable.
Sensor lines leading to other separator cards must
be looped in separate screened cables.