I would like to seek your advice regarding the requirements in NFPA 850 about the transformer separation requirements which require a firewall depending on the transformer oil capacity. In our case, the closest building in front of the power transformer(oil capacity is greater than 5000 gals) is approximately 20m. However, between the transformer and the closest building are public road and transformer access road. Note that the AJH required to provide a boundary wall separating the public road and transformer access road to minimize the effect of possible transformer explosion to the public. My question is, do we have to provide a boundary wall that is higher than 1ft from the conservatory tank as the highest point of the transformer? and the wall will be provided 8m away from the edge of the transformer oil containment.
Please see attached file for a visual understanding of the above.
Thank you in advance.