Publicité
Manual BVS 21 ATEX E 069 X
The minimum and maximum cross sections of
conductor that can be connected must be taken
into account (see Section 3, Technical data).
All screws and/or nuts on the terminals, including
those that are not in use, must be securely tight-
ened. Applying excess torque, however, can
damage the connection.
4.5
Terminals for earthing or equipotential
bonding
Particular attention must be paid to the con-
nections for protective conductors.
The enclosures are fitted with an internal and an
external connection for the earth conductor (PE)
or the equipotential bonding conductor.
The number of terminals provided for the PE
must be at least equal to the number of circuits.
The minimum permissible cross section of the
PE terminal is shown in table 2 as a function of
the maximum permissible cross section of the
associated phase and neutral terminals.
Maximal permissible cross
section of the phase or
neutral terminal
2
S [mm
]
≤ 16
> 16 bis/à/to 35
> 35
Table 2:
Minimum cross section of the PE conductor
terminal
4.6
Equipotential bonding and PE conductor
From the standpoint of intrinsic safety Ex i, a dis-
tinction must be made between the equipotential
bonding conductors and the PE conductors in
the installation. The bonding conductor is regard-
ed as a passive conducting element that fulfills
the required separation conditions with a 500 V
insulation test. The PE conductor, however, is at
a certain potential in the event of a fault, and is
regarded as an active, non-intrinsically safe ele-
ment.
Edition October 2021
Copyright
Minimum cross section of
the associated protective
conductor terminal
2
Sp [mm
]
S
16
0.5 · S
17
thuba Ltd., CH-4002 Basel
Switzerland
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