Installation of EX-Proof Devices 35
English
6 Installation of EX-
Proof Devices
Make sure that the entire interconnec-
tion of intrinsically safe components
remains intrinsically safe. The operator is
responsible for the intrinsic safety of the
overall system.
6.1 Overvoltage protection
If the probe is used as electrical equip-
ment of category 1 G, then a suitable
overvoltage protection device must be
connected in series (apply the valid regu-
lations for operating safety as well as
EN60079-14).
6.2 Zener Barriers
The operation of an intrinsically safe
probe in intrinsic safe areas requires the
use of a Zener barrier.
The minimum supply voltage VS
min of
the transmitter must not fall short. The
minimum supply voltage has been
defined in the respective product-
specific data sheet under "Output signal /
supply".
In order not to fall below VS
min, it is
important to verify which minimum sup-
ply voltage is available at full level control
of the transmitter. Make sure the Zener
Barrier you chose fits these requirements.
DANGER
Danger of explosion! Do not work on
any parts under current while the
explosion hazard is present!
6.3 Galvanically Insulated
Amplifier
When installing the intrinsically safe
device as zone-0-equipment, the supply-
ing must be carried out by a power sup-
ply which must be galvanically insulated
and which must not be grounded.
When using a galvanically insulated
amplifier with linear bonding, note that
the terminal voltage of the transmitter
will decrease like it does with a Zener
barrier. Furthermore, you have to note
that the supply will additionally decrease
with an optionally used signal amplifier.
When selecting the supplied devices, the
maximum operating conditions must be
observed. When assessing these, refer to
their current data sheets to ensure that
the entire interconnection of intrinsically
safe components remains intrinsically
safe.
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