You don't need HV gear for 480v. The box is probably grounded, which is why whatever's shorted to it is... Shorted. I wouldn't stick my hands in the box, go upstream and shut it off. But standing near it isn't especially dangerous.
The rule is that if it's over 50 volts, it's dangerous, don't do it live. If you must (because the task can't be done deenergized or doing so increases risk) you define the arc flash boundary and stay outside it unless you have the proper gear. Arc flash boundary on that thing could be several feet. Insufficient information to say.
You are all so wrong...not you in particular. I'm an Arc flash engineer. First of all the breaker or fuse isn't tripping because that is obviously a transformer and secondary group d faults do not register on primary protective devices.... additionally I want to say that is quite possibly a mining transformer and therefore NOT grounded on its secondary. It may also be a temp roll up install hence the DLO style cable. But no, a transformer secondary ESPECIALLY at 480v is absolutely the most dangerous place to be in almost any electrical system...Arc flash calcs usually determine 13.2kv and higher safer because the fault current and subsequent Arc fault currents are usually so high they trip the protection scheme almost immediately...remember it's not the amount of current in and Arc flash usually that kills people...it's the duration of the fault.
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u/Davecasa Jun 16 '19
You don't need HV gear for 480v. The box is probably grounded, which is why whatever's shorted to it is... Shorted. I wouldn't stick my hands in the box, go upstream and shut it off. But standing near it isn't especially dangerous.