Is possible to accidentally flex the house outlet so it become 600v?
Answers: Your "electrician" is probably an idiot fly by night guy.
I really hold no idea where on earth he got that. The merely thing I can integer is he read the lettering on the insulation. Wiring like NM (Romex) have a 600V rms insulation rating. This means the insulation will withstand 600V, it doesn't connote that the wiring have 600V on it.
If your purifier had 600V on it it would enjoy died a violent demise and you would certainly hold known it without hesitation. A 600V arc is not self extinguishing and you would have see immediate and severe warmth and arc flash damage.
The max you can go and get in a residence is 240V stripe to line and 120V string to neutral. These are nominal voltages and what you consider will vary but it sure won't be 600V.
Go bring back a meter, put it on this circuit and tell this guy he doesnt know what hes chitchat about.
Its pretty difficult, they would own had to run a powerline directly to an outlet minus any resistors. It would take a moron.
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