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 Baseefa - what
to consider!
    
Intrinsic safety differs from other forms of protection because it is
based on the principle that the equipment is electrically safe. The
definition of an intrinsically safe circuit is generally one that does not
contain sufficient electrical energy, even under fault conditions, to
cause a spark or generate sufficient heat to ignite a combustible gas
mixture. Under the current standards, Ex ia equipment is tested with two
coincident faults applied to the system. Ex ib equipment is tested with
one fault.
Intrinsic safety requirements are covered by European Standards BS
EN50014, EN50020 and EN50039, and the guidance Standard EN50073. In the
United States the relevant Standard is UL 913 "Intrinsically Safe and
Associated Apparatus (for use in Class I, II and III Division 1, Hazardous
(Classified) Locations).
Other forms of protection are based on mechanical safety and for
flameproof equipment the equipment enclosure should be capable of
containing an explosion within it, thereby avoiding the possibility of the
system becoming an external ignition source.
Flameproof requirements are covered by European Standard EN50018,
BS4683 : Part 2 :1971, BS5001 : Part 5 1977 and the guidance Standard
EN50073. In the United States the relevant Standard is UL 1203
"Explosion Protected and Associated Apparatus (for use in Class I, II
and III Division 1, Hazardous (Classified) Locations)."
Product must be manufactured by a BASEEFA approved contractor.
ACL can take the product from concept through design, approval and
manufacture |
