Special detectors
Safety barrier SB3
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10.10 Safety barrier SB3
Device for zone 0, 1 and 2 areas at risk of explosion
10.10.1 Functions
If fire detectors are being installed and operated in potentially explosive
atmospheres, the installations and apparatus must conform to country-specific
safety regulations. Fire detector circuits usually only require a small amount of
electrical energy. Ignition protection category 'intrinsic safety' Ex i is suitable for this
application. This is based on standards EN 50014 (EN 60079-0) and EN 50020
(EN 60079-11). A safety barrier limits the electrical energy between non-
intrinsically safe and intrinsically safe circuits.
Safety barriers limit electrical power to a level that is low enough to prevent
electrical sparks from igniting a gas mixture. Safety barriers SB2 and SB3 are
approved for ignition protection category [Ex ia] IIC/IIB. At the output of the safety
barriers, only equipment that conforms to country-specific regulations and is
approved for intrinsically safe ignition protection category Ex ia or Ex ib may be
connected.
Observe national guidelines and regulations.