I had an issue where the wires in the whole-house AC were getting caught in the fan. In fixing that, I was checking for voltage, and there was 110 VAC between the starting capacitor and the shell of the box. I switched off the AC breaker, but there was still 110. I switched off the furnace breaker also, but there was still 110 between the cap and the shell. There’s a little box with a blade cutoff switch (not sure of the correct name) that I pulled out, and that finally killed the 110.
I’ve re-routed the wires so they don’t get caught in the fan blade, but I’m concerned about the breakers not killing the power.
Is this a problem? (Yeah, I probably already know the answer, but maybe there’s some weird wiring pattern used by HVAC installers.)
More generally, any suggestions? I have already found one pair of circuits that were cross-circuited, but I wouldn’t expect that from a dedicated 240V AC circuit.
Is it more likely the furnace circuit or the AC circuit that’s miswired and providing the voltage?