VEGA VEGAPULS 54K enamel - Manual (Page 15)

VEGAPULS 54K enamel 15
24 101-EN-041227
Electrical connection
3 Electrical connection
3.1 Connection and connection
cable
Safety information
As a rule, do all connecting work in the com-
plete absence of line voltage. Always switch
off the power supply before you carry out
connecting work on the radar sensors. Pro-
tect yourself and the instruments, especially
when using sensors which do not operate
with low voltage.
Qualified personnel
Instruments which are not operated with
protective low voltage or DC voltage must
only be connected by qualified personnel.
Connection and screening
A standard two or four-wire cable (sensors
with separate supply) with max. 2.5 mm
2 wire
cross-section can be used for connection.
Quite often, the "electromagnetic pollution"
caused by electronic actuators, energy ca-
bles and transmitting stations is so consider-
able that the sensor cable should be
screened.
We recommend the use of screened cable.
Screening is also a good preventative meas-
ure against future sources of interference.
Ground the cable screen preferably on the
sensor.
It is a good idea to ground the cable screen
on both ends. However, you must make sure
that no ground equalisation currents flow
through the cable screening. Ground equali-
sation currents can be avoided by potential
equalisation systems. If ground equalisation
cables are not available, grounding on both
ends can be realised by connecting (e.g. in
the switching cabinet) one end via a capaci-
tor
1) to the ground potential. Use a very low-
resistance ground connection (foundation,
plate or mains earth).
Note!
In Ex applications, grounding on both ends is
not allowed due to potential transfer.
Ex protection
If an instrument is used in hazardous areas,
the respective regulations, conformity certifi-
cates and type approvals for systems in Ex
areas must be noted (e.g. DIN 0165).
Intrinsically safe circuits must not be con-
nected with more than one active instrument
(i.e. an instrument delivering electrical en-
ergy) must not be connected. Please note
the special installation regulations (DIN 0165).
Connection cable
Make sure that the connection cables are
specified for the expected conditions in your
systems. The cable must have an outer diam-
eter between 5 and 9 mm (1/2 to 1/3 inch), or
with Ex d housing, 3.1 … 8.7 mm (0.12 to
0.34 inch). Otherwise, the seal effect of the
cable entry would not be ensured.
Cables for intrinsically safe circuits must be
marked blue and may not be used for other
circuits.
Earth conductor terminal
On VEGAPULS 54 sensors, the earth con-
ductor terminal is galvanically connected to
the flange.
1) max. 10 nF, e.g. voltage resistance 1500 V,
ceramic.