8
3
Application
3.1 Maintenance, service
The transfer characteristics of the devices remain stable, even over long periods
of time, thus eliminating the need for regular adjustment. Maintenance is there
fore not required.
3.2 Fault elimination
Units that are operated in connection with potentially explosive atmospheres
must not be modified in any way. Repairs on a unit may be carried out only by
specially trained and authorized specialist personnel.
3.3 Insulation coordinates for units with Ex certification
according to EN 60079‐11
The units are determined for use in degree of soiling 2, per EN 60664.
3.4 Ambient conditions
Ambient temperature: -20 °C ... +60 °C ( -4 °F ... +140 °F )
Storage temperature: -25 °C ... +70 °C ( -13 °F ... +158 °F )
Humidity: max. 75 % relative humidity without condensation
3.5 Operating principle
Safety barriers form the interface between intrinsically safe and
non‐intrinsically safe circuits. It is their task to limit the energy transmitted from
the non‐Ex area to the Ex area, both in normal operation and in the event of a
fault.
The barrier limits the current and voltage in the intrinsically safe circuit if the
voltage on the non‐intrinsically safe side reaches excessively high values or if
a short circuit occurs on the intrinsically safe side.
In normal operation the voltage between terminals 7 and 8 or 5 and 6 is less
than the breakdown voltage U
only a small leakage current through the diodes.
HBM
of the Zener diodes, and therefore there is
Z
SB01A
A1020-4.0 en/de/fr