208/120 panel used as 480 panel

[fisherelectric]

Not to mention the fact that some electrician could assume he was working on a 120/208v system if he only read the voltage off the panel cover. Adding a 120 v circuitcircuit....working it hot assuming the wrong voltage...etc. Could make for a big surprise. I once worked on a hi-leg service that was marked 120/208v. Specs called for an isolating transformer at 208 volts for a cat scan machine working at 208v. They bought all the wrong equipment and no one knew til I tested the voltage before hook-up.

 

[smithacetech]

I have noticed that some manufactures rate their products at 600V.
SQ D for example. Their I-line panels & busway both can be used at 208v or 480v. The difference is the breakers. They basically build it for the ampacity rating, which of coarse is the same for either voltage.
Basically the same as for wire. Most all wire is rated at 600V, it doesnt care if it has 208v or 480v running on it as long as it doesnt exceed its ampacity.

(like Jref explained)

My guess though, if this was a smaller panel & listed for 208V more than likely it would only accept 208V breakers. Exceeding the voltage on the breakers was definately a dumb thing to do.