User Manual

Safety notes
2.3 ATEX for intrinsically safe circuits
SIRIUS ACT 3SU1 pushbuttons and signaling devices
26 System Manual, 02/2015, A5E03457306020A/RS-AB/002
2.3
ATEX for intrinsically safe circuits
The intrinsic safety of a circuit is achieved by limiting the current and voltage. This property
limits the "intrinsically safe" protection type to circuits with relatively low power. Suitable
applications are found, for example, in measuring and control engineering.
The purpose of pushbuttons and signaling devices is to reliably signal conditions (for
example, sources of faults or interference factors) on machinery and installations so that the
affected equipment can be controlled and brought into a safe state if a hazardous situation
develops.
From our portfolio of pushbuttons and signaling devices, non-illuminated actuators, contact
modules, empty enclosures and special accessories (see table below) are categorized in
accordance with the ATEX Directive 94/9/EC as simple electrical equipment and are thus
suitable for use in intrinsically safe circuits.
The devices listed in the overview below are assigned to Temperature Class T4.
3SU1 pushbuttons and signaling devices
Type
Version
Basis for approval
Actuating and signaling ele-
ments
3SU10.0-…..-….
3SU10.2-…..-….
3SU11.0-…..-….
3SU12.0-…..-….
Plastic or metal version Simple electrical equipment
according to DIN EN 60079-
11
Contact modules 3SU1400-.AA10-..A0
3SU1400-.DA..-.AA0
Spring-loaded terminals or
screw terminals
Holders 3SU1500-0AA10-0AA0
3SU1550-0AA10-0AA0
Plastic or metal version
Empty enclosure
3SU18..-.AA..-….
Plastic or metal version
Accessories 3SU19.0-0A…-0..0
3SU19.0-0B…-0..0