Transformer area calculation

[Davidson84]

Im designing a deluge system for a 230 kV transformer in a electrical power station, at the moment of calculate area of transformer NFPA 15 suggest the following: "The water shall be applied al a net rate not less than 0.25 gpm/ft2 of the proyected area of a rectangular prism envelope for the transformer and its appurtenances,..." so I most consider ONE big rectangular prism that contains body transformer, radiators and oil conservator tank, in this case its include a non-existent surface area but I guess its a like a security margin. Im doing it fine?

 

[chicopee]

I would not advise a water sprinkler protection for such a room. I always believe that it is best to have such electrical equipment in a separate fire resistive room.

 

[cdafd]

Might just be an outside transformer

 

[Davidson84]

Actually is an outdoor oil-insulated transformer...

dont try, do it!

 

[chicopee]

I have never seen water deluge or sprinkler protection for transformers whether outside or inside of buildings and I have done "tons" of property surveys.

 

[cdafd]

http://www.firefightingindia.com/Big-image/transformer-protection-5.jpg

http://www.sinclairfire.com.au/uploads/52/37/08082009162.jpg

http://www.diamondelectricals.com/images/protectowire/lhs12_2.jpg

 

[cdafd]

http://www.eng-tips.com/viewthread.cfm?qid=327639

http://www.sfpe.org/LinkClick.aspx?fileticket=XKjV3Tf3sME=&tabid=259&mid=743

 

[LCREP]

Chicopee

If you look at power plants you will see a ton of deluge systems protecting transformers along with fire walls on either side of the transformer.

 

[chicopee]

I'll take a look at some of the local power plants in our area in due time.

 

[GeorgeMech]

Chicopee,

It depends upon the area and the AHJ. Most of the transformer here in Qatar is protected by deluge water spray system and it's a requirement from the AHJ.

 

[GeorgeMech]

Davidson,

Your assumptions are correct but remember that this is only "theoretical", minimum demand required. When you are using the actual spray nozzle, it tends that the demand of the system is more compared to the theoretical value.

 

[3cio]

Good day!

Georgemech is right, in qatar a lot of deluge system was done for an outdoor transformer.

 

[Davidson84]

Thanks Guys for your comments, actually I'm checking some data sheets about blast preventing systems for oil-isulated outdoor power transformers, I dont have so much time working on Fire prevention in my job, but this forum has been very useful as long as I've been studing the NFPA standard.

dont try, do it!

 

[DavidCR]

Chicopee, US standards like UL, IEEE and insdustrial standards like from "B. of Reclamation" (

http://www.usbr.gov/power/data/fist/fist3_32/fist3-32.pdf)

use deluge systems for outdoor transformers. NFPA 850 and 15 guive guidelines as recomendadtions but for UL and "Reclamation" is obligatory in some conditions.

 

[DavidCR]

For the area question.
Wether you supose a prism or take on account all oil cointainig exposed parts. At the end the hyd. calculatins will tell you if you are using enough water for a range of pressure conditions. Depending of the geometry you shall also include areas underneath radiators, big spaces between tank and radiators,etc. So you can do and aprox calcution based on prsim but when you locste all the nozzles and define diameters yo shall check enough water is cooling all required surfaces at least with 0.25gpm or so.