VEGA VEGAPULS 56K - Manual (Page 24)

24 VEGAPULS 56K
22915-EN-041227
Electrical connection
4 Electrical connection
4.1 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 cable
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 two or four-wire cable must be
screened.
We recommend the use of screening. The
screening is also a precautionary measure
against future sources of interference. Con-
nect the cable screen to earth on two ends
(on the sensor and on the processing sys-
tem) only if you have determined by meas-
urement that no or only low earth
compensation currents flow over the
screens. Use a very low impedance earth
connection (foundation, plate or mains earth).
Ex protection
If an instrument is used in hazardous areas,
the appropriate regulations, conformity and
type approval certificates for systems in Ex
areas must be noted (e.g. DIN 0165).
Connection cable
Make sure that the connection cables are
specified for the expected application condi-
tions in your systems. The cable must have an
outer diameter between 5 and 9 mm (M20x1.5)
or 3.5 … 8.7 mm (
1 /
2
“ NPT). Otherwise, the seal
effect of the cable entry would not be ensured.
Cables for intrinsically safe circuits must be
marked blue and must not be used for other
circuits.
Earth conductor terminal
On all VEGAPULS 56 sensors, the earth
conductor terminal is galvanically connected
to the metal process connections.
4.2 Connecting the sensor
After mounting the sensor at the measure-
ment location according to the instructions in
chapter „3 Mounting and installation“, loosen
the closing screw on top of the sensor. The
sensor lid with the optional indicating display
can then be opened. Unscrew the sleeve nut
and slip it over the connection cable (after
removing about 10 cm of cable mantle). The
sleeve nut of the cable entry has a self-lock-
ing ratchet that prevents it from opening on
its own.
Now insert the cable through the cable entry
into the sensor. Screw the sleeve nut back
onto the cable entry and clamp the stripped
wires of the cable into the proper terminal
positions.
The terminals hold the wire without a screw.
Press the white opening levers with a small
screwdriver and insert the copper core of the
connection cable into the terminal opening.
Check the hold of the individual wires in the
terminals by lightly pulling on them.