Design of blast wall between transformers

[anjande]

Do you know how a blast wall is designed for the Transformer yard between two transformers? Basically, the question is what should be the design criteria or loading for such design? Also, what are the expected thickness of such wall ( RCC) per NFPA and Underwriters laboratories.Which code should be referred to find out the thickness of blast wall?

May I expect a reply on my above queries soon? Please respond.

 

[DavidCR]

On NFPA 850 3-2.4 you find requirements for fire walls or walls to separate transformers and transformers and buildings.

For outdoor transformers (500 usgal oil or more) the walls should be 2-hr fire walls according to NFPA 850.

Also they indicate that the barrier should be designed to withstand the effects of exploding tranformer bushings or lighting arrestors. So in this last point I see that NFPA is not clear and agree with you in the need of a more specific design creteria.

 

[arsir]

I NEED HELP TOO...WITH NFPA
I am an electrical engineer and recently I had a situation where one 100KVA,11/0.4kV ,oil filled transformer with oil cpacity much under 500 ltrs is to be installed outdoors in a isolated fenced area. I have assumed that portable cemical fire extinguishers shall be sufficient to provide safety for this installation. I could not find specific recommendations for transformers with less than 1893 Ltrs of oil in NFPA850.
I need to justify my installation recommendation with some standard.
Could someone help me in this? I would welcome advise regarding what specific fire safety measures must be taken and also which standards govern such requirements.