Dry Transformer Vents

[farmaped]

Indoor NEMA 1 Dry Type Transformers, industrial facility. Is there an arc flash concern, from the visible buss (through the vents)? 2000KVA transformer can result in some lengthy boundaries. Is this cause for concern or am I thinking too much.
Thanks

 

[barbeer]

There is always a concern....in a catastrophic failure I am sure it would get ugly if all the planets were lined up.

 

[jim dungar]

Indoor NEMA 1 Dry Type Transformers, industrial facility. Is there an arc flash concern, from the visible buss (through the vents)? 2000KVA transformer can result in some lengthy boundaries. Is this cause for concern or am I thinking too much.
Thanks

Transformers can be difficult. Are you reporting values (i.e. boundaries) based on the primary? Or are you using the secondary ones? What about the probability that a secondary fault (in the transformer compartment) will engulf the primary and become a primary fault?

Some of my customers want to calculate both primary and secondary AFIE and then label the equipment with the worst values. Their combined label usually ends up with the primary voltage boundaries and the secondary HRC value and boundary.

 

[zog]

Indoor NEMA 1 Dry Type Transformers, industrial facility. Is there an arc flash concern, from the visible buss (through the vents)? 2000KVA transformer can result in some lengthy boundaries. Is this cause for concern or am I thinking too much.
Thanks

You only need be concerened when "Interacting" with the equipment, the chance of an arc flash occuring without any interaction is small enough to be 9for lack of a better word) ignored.

 

[farmaped]

Makes sense. While accessing the equipment we mark out a standard 10FT boundary, which is above the calculated. I also post the "worst case" scenerio arc flash warning label. thanks