MAN3041-1
3
1
Introduction to Intrinsic Safety
There are many places where an explosive mixture of air and gas or vapour is
—
or may be
—
present
continuously, intermittently or as a result of an accident. These are defined as hazardous areas by BS EN
60079, the code of practice for installation and maintenance of electrical apparatus in potentially explosive
atmospheres.
Hazardous areas are common in petroleum and chemical engineering plants and in factories processing and
storing gases, solvents, paints and other volatile substances.
Electrical equipment for use in these areas needs to be designed so that it cannot ignite an explosive
mixture, not only in normal operation but also in fault conditions. There are a number of methods available
to achieve this but one of the most common is intrinsic safety.
Orbis
™
IS is a range of conventional detectors which has been developed from the standard range of Orbis
smoke and heat detectors.
Orbis IS is a range with modern styling and a TimeSaver IS base. It is electrically compatible with Series 60
intrinsically safe conventional detectors.
Orbis IS is suitable for use in marine and offshore applications as well as in land-based systems and has
been tested and approved to the following standards:
European Standard EN54
Fire Detection and Fire Alarm Systems
:
EN54
–
7: 2000
Optical smoke detector
EN54
–
7: 2000 & CEA 4021: 2003
Multisensor smoke detector
EN54
–
5: 2000
Heat detector
Electromagnetic Compatibility
EN61000-6-3
EN50130-4
ATEX-related standards
:
BSEN60079
–
0:2004
IEC60079
–
0:2004
EN50020:2002 and EN/BSEN/IEC60079
–
26:2004
Marine type approval standards:
American Bureau of Shipping (ABS)
Rules for Building and Classing Steel Vessels 2006
Bureau Veritas (BV)
Rules for the Classification of Steel Ships 2005
Det Norske Veritas (DNV)
Standard for Certification No 2.4: 2004
Germanischer Lloyd (GL)
Rules for Classification and Construction 2003