Where to Buy Associated Non-Incendive Field Wiring Apparatus?

[themoke]

I see reference to Associated Non-Incendive Field Wiring Apparatus on equipment Control Drawings all the time. The definition from ISA 12.12.01-2013 is as follows:

associated nonincendive field wiring apparatus
apparatus in which the circuits are not necessarily nonincendive themselves, but that affect the
energy in nonincendive field wiring circuits and are relied upon to maintain nonincendive energy
levels.

I'm having a hard time trying to find where can you purchase a device that bears this name. Any ideas? It sounds like it essentially serves the same function as an I.S. barrier. Perhaps I.S. barriers are intended to be used for this purpose as well? If you have installed NIFW(non-incendive field wiring) circuits, please reply with what equipment you used for your 'Associated Apparatus'. This is general question about Non-Incendive Field Wiring, I don't have a particular application in mind.

Thanks!
Mike

 

[ScottyUK]

From IEC 60079-0, 'associated apparatus' is "Electrical apparatus which contains both energy-limited and non-energy-limited circuits and is constructed so that the non-energy-limited circuits cannot adversely affect the energy-limited circuits"

Associated apparatus could be a zener barrier, a galvanic isolator, or something which incorporates one or other of those functions within it. An example of something which incorporates it would be Moore's SPA[sup]2[/sup] trip amps.