Transformer Fire prtoection

[15121981]

Hi,

We have Oil filled transformer in cable cellar area part of our substation.

(Cable cellar: we mean that swithcgear has been kept at First floor level & on ground the cable layed & are terminated in switch gear)

Transformer are covered all the three side with 2 hr fire rated wall (including back side towards cable cellar area & other two side we have another transformer separated by fire wall) & front side fencing gate for ventilation.The Roof of this transformer are covered with sheated roof panel.

Following i need to discuss.

1. Is this transformer we will consider as outdoor or indoor based on above condtion
2. Does this required fire protection as water spray system for more than 500 gallon oil capacity.

 

[chicopee]

I remember this issue was raised sometime ago and one of the responders had posted a picture of an automatic fire suppression system for a power transformer located outside. Is the structure isolated or attached to a building?

 

[15121981]

thanks for responding. We have transformer kept at ground floor attached to building.

e.g we have 24 meter building the central part 18 meter we have concrete slab and 6 meter arms on both side for transformer bay.Hope this clarify your query,please find the attached sketch

 

[chicopee]

I have seen many transformer either oil filled or dry type in structure with and without automatic sprinkler protection. With you attached building, if its fire resistance is adequate, then, forgo the expense of fire suppression. Also consult with your fire insurance carrier as it may have a different requirement.

 

[NightME]

I don't think the sketch was attached

 

[15121981]

I hope this time sketch link is attached.

 

[cdafd]

Will the entire building have a fire sprinkler system already ???

 

[ZDR1985]

Normally oil filled transformers with 500gal oil and more is protected by high velocity spray system. But, I have seen transformers with that size that doesnt have spray system. As long as fire walls and separation distance to a building is in accordance with NFPA 850.

Ref. NFPA 850

7.8.6* Transformers. Oil-filled main, station service, and startup
transformers not meeting the separation or fire barrier
recommendations in 5.1.4 or as determined by the Fire Protection
Design Basis Document should be protected with automatic
water spray or foam-water spray systems.
7.8.7* Substations and Switchyards. Substations and switchyards
located at the generating facility and utilizing combustible
oil–filled equipment should be protected by the yard fire hydrant
system where practical. Spatial separation of transformers and
other equipment containing over 500 gal (1893 L) of oil should
be in accordance with 5.1.4. Consideration should be given to
water spray protection of transformers critical to the transmission
of the generated power.