over 600V equipment - cutouts
over 600V equipment - cutouts
(OP)
I'm dealing with an old building on a campus that has 2400V distribution distributed in tunnels around the campus. 2400V power distributes to several individual vaults located below the different buildings on the campus. The campus is under its own jurisdiction, so it's hard to say how much oversight the installation of the electrical distribution has had. I typically work with 480V power, so I've briefly had to look through the "over 600V" code to see if there's anything I need to rectify in the vault. The vault I'm working in utilizes cutouts where the 2400V power enters the vault. Section 490.21(C)(1) indicates that "distribution cutouts shall not be used indoors, underground, or in metal enclosures."
I've also found an OSHA article that indicates the following:
1910.308(a)(5)(iii)
"Fused cutouts installed in buildings or transformer vaults shall be of a type identified for the purpose. Distribution cutouts may not be used indoors, underground, or in metal enclosures. They shall be readily accessible for fuse replacement."
why would is say "installed in buildings or transformer vaults" if cutouts are not allowed to be installed indoors? I may be dealing with a nomenclature issue as well, as the "cutouts" appear to just be current limiting fuses/disconnect switches that can be opened/closed via an insulated handle.
any insight would be greatly appreciated!
I've also found an OSHA article that indicates the following:
1910.308(a)(5)(iii)
"Fused cutouts installed in buildings or transformer vaults shall be of a type identified for the purpose. Distribution cutouts may not be used indoors, underground, or in metal enclosures. They shall be readily accessible for fuse replacement."
why would is say "installed in buildings or transformer vaults" if cutouts are not allowed to be installed indoors? I may be dealing with a nomenclature issue as well, as the "cutouts" appear to just be current limiting fuses/disconnect switches that can be opened/closed via an insulated handle.
any insight would be greatly appreciated!






RE: over 600V equipment - cutouts
That said, you may be missing the subtle difference in those statements. "Distribution cutouts" are not the same as "fused cutouts" used in transformer vaults etc. They are the open style devices that are used on utility poles and switchyards by the utilities, operated from the ground by a lineman with a long fiberglass pole.
Distribution cutout:
Fused cutout in a transformer vault:
Still operated by a pole.
And sometimes people use the wrong terms for what is being implemented. If it is an enclosed switch with its own handle on the outside, it's more likely a Fused Load Interrupter Switch:
Or if you are not sure if there are fuses inside, a Vacuum Switch, an SF6 gas switchor even an Oil Switch, (although usually for 15kV class systems, they are sometimes used at lower voltages, especially underground).
And here is why the code says that you can't use open style distribution cutouts indoors...
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RE: over 600V equipment - cutouts
OK, the explanation was pretty good as well.
RE: over 600V equipment - cutouts
Good on ya,
Goober Dave
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RE: over 600V equipment - cutouts