Elster Instromet 83 480 540, Руководство по эксплуатации и инструкции по установке

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Function Expansion Unit FE260
Elster-Instromet GmbH 11
3.2 Screening and earthing
The cables for connection to the intrinsically safe electrical circuits (blue terminal block)
and to the outputs A1 to A4 have a screen which must be earthed at both ends to prevent
interference due to high frequency electromagnetic fields.. The screen must be connected
all round, complete and flat. The FE260, similar to the volume corrector (e.g. EK260) to be
connected, has special metallic EMC cable glands for this.
3.3 Intrinsically safe electrical circuits
The FE260 is approved according to DIN EN 50020 as “associated electrical equipment” in
the Category “ia” (see Chapter A-2). The blue terminal block on the right-hand side
includes three intrinsically safe circuits. If an intrinsically safe device is connected to them
(e.g. an EK260 volume corrector) which is located in the area subject to explosion hazards
(Zone 1), then the appropriate regulations must be followed. The implications of this
include:
!
Follow the stipulations in the relevant regulations and standards, in particular DIN
EN 60079-14 (VDE 0165 Part 1) and DIN EN 50014.
!
Make sure that the limits quoted in the certificate of conformance (Chapter A-2) do
not exceed the limits quoted in the certificate of conformance for the intrinsically
safe device to be connected.
!
Only cable may be used for the intrinsically safe electrical circuits which fulfils the
following requirements according to DIN EN 60079-14, Section 12.2.2.1:
Insulated cables with a proof voltage of at least 500 VAC between conductor-earth,
conductor-screen and screen-earth.
If fine-stranded conductors are used, the conductor ends must be protected
against splaying out, e.g. by the use of wire-end sleeves.
The diameter of individual conductors as well as single wires in fine-stranded
conductors must not be less than 0.1 mm.
!
Since the cable screens are connected at both ends, the volume corrector housing
must be electrically connected to the earthed housing of the FE260 via a potential
equalisation conductor. The potential equalisation conductor must have a cross-
sectional area of at least 4 mm². (DIN EN 60079-14, Sect. 12.2.2.3).
The FE260 is earthed using terminal "c" in Fig. 4 (page 9).
Furthermore all other relevant requirements in DIN EN 60079-14 must be fulfilled.
Screened cables must be used for reasons of electromagnetic compatibility (EMC). In this
respect, labelling of the cables or a special sheath colour is not necessary according to
DIN EN 60079-14, Sect. 12.2.2.6.