Hi James,

This is helpful data, thanks. I just bought the equipment necessary to do 480V testing so I hope to have better answers for you soon.

It sounds like this is not the same bug as the 240V AC disconnection, because in that case the meter did not reboot.

I have a suspicion. If it’s convenient, can you try manually setting the meter to the 600VAC range before connecting it to the 480V circuit? My hunch is that there’s some sort of deviance in the overload protection circuit, and since the meter defaults to 60V measurement mode, 480V is overloading it in such a way that it forces a reboot before the autorange can kick in. If my hunch is correct, I’ll write a patch.

Thanks again, best
~James