Oil type transformers in Hazardous Area

[MYAMYAMYA]

Hello all

What could be the applicable standards (ANSI/IEEE/IEC/NEMA, etc) in case of the requirements of installing 4.16/0.48 kV Loop feed pad mounted oil immersed transformers in hazardous area ( typically should be ZONE 2 with Heavy Industrial Air Condition)? I know only LV/LV dry type transformers can be installed in such areas with special certification but never seen MV transformers in such areas.

Thanks

 

[iceworm]

Disclaimer: All my experience is with CI, D1, or D2 - no Zones. So there could be minor differences.
I have never seen oil filled transformers in classified areas. Probably because of all the protective switches, oil level, winding temperature, rapid rise ... I've never seen any that were rated for classified areas.


Harmless flakes working together can unleash an avalanche of destruction

 

[RRaghunath]

If it is synthetic oil like silicone fluid that has high flash point (>300degC) and doesn't sustain fire on its own, may be it could meet the hazardous area requirement! Just a thought.

 

[moltenmetal]

Oil immersion is, unless I misremember, a method of protection permitted for SOME hazardous area classification purposes (along with methods such as explosion proofing, hermetic sealing, intrinsic safety etc.). Which ones? Look at the codes.

 

[ScottyUK]

In the IEC areas of the world, oil fill is an acceptable protection concept, Ex 'o' and listed under EN 60079-6. Transformers are permissible up to fairly high voltages, and instruments with sparking contacts may be either intrinsically safe or flameproof types. I'm at home and don't have the standards to hand.