I have a question regarding NFPA 70 rules and how they would apply to outdoor transformer work. The transformers range from 500 to 3000 KVA. Is it common practice for specialized service contractors to perform work such as: power washing, grinding, painting, patching, and oil sampling with the units energized? There are no bare conductors as the connections have been booted. They also opened the doors because there was a section of the door that was completed rusted.
Exterior transformers
- Thread starter dippy
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petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I think that at least some of these activities might well be deemed a low enough risk that they might be acceptable. Someone would need to take a very close look at just what is being done and the specific circumstances.
It is possible that a specific activity is deemed safe on one transformer and the same activity not deemed safe on another transformer.
Personally, I would be very suspicious of opening the doors and declaring it "safe". However, if there are no exposed energized conductors with the doors open, who knows what someone might legitimately decide. My theory on what constitutes exposed with the doors open is that if someone deliberately tried to contact an energized conductor, it could be done.
With the doors closed, I would be inclined towards a little more leniency on what constitutes exposed.
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