Need 240V for a test?
This'll work.
(Note: do not do this)
And to explain for all my non-North American peeps, these two cords go to plugs that are on adjacent breakers in the panel. That means across the two hot wires you'll get 240V rather than 120V.
So, in a pinch, you can just do this.
Should you? No. But it's possible.
@TechConnectify Tell me you're not using GFCI without telling me you're not using GFCI! :)
@TechConnectify @david Just measuring that won’t trip a GFCI. I think that US ones need something like a 5-10mA imbalance to trip. A multimeter will typically have an input impedance of 1-10 MOhm, which gives well under 1mA on 240V. As a demonstration, both the visible outlet and the outlet the extension cord is plugged in to have GFCIs.
@cbane @TechConnectify fair, but it was implied that he actually used it that way.
@cbane @TechConnectify @david As long as both phases go through the same GFCI, I think it wouldn't trip even if a load was connected to it.
@danimrich @david That’s true as far as it goes, but it’s a pretty rare configuration in the US. Pretty much all of our GFCIs are either combined with a circuit breaker and protect that one circuit, or they’re combined with an outlet and protect that outlet and any downstream ones. The only somewhat common way I know of is for the two circuits to be part of a multiwire branch circuit. https://diy.stackexchange.com/questions/71652/what-is-a-multiwire-branch-circuit
@david heh, I hadn't thought about that. Indeed these circuits are not GFCI protected. But it came in handy just now!