I recently moved into a new house and I've been mapping my panelboard. I've got pretty much everything mapped except for a couple circuits. I know there are some experienced folks on here so I thought I'd see if anyone could weigh in on what I'm looking at here or had any advice.
Some context, I live in the northeast of the US and many of the appliances are gas powered (stove top, gas boiler, water heater, and dryer). The largest electrical loads on the panel from what I can tell are the condenser fan/compressor unit on the outside of the house and the AC/blower unit in the attic. Each of those are on their own 240V 20A circuit. Everything else, except for one circuit (next paragraph), is a single pole 20A or 15A circuit.
I've mapped each breaker by opening it and then checking the voltage at the terminals and then checking the lights/outlets throughout the house. What I'm having some trouble with is the following:
- There is a 240V 30A circuit and I have no idea what it is connected to. Even if I were to open it, how would I know what to look for if I don't have any idea what it might be powering? I'm confused because I'm not sure what other load in the house would require a circuit that size. There are no major electrical heating elements that I know of (its all hydronic) and the only large motor loads are the compressor/condenser fan motor and attic unit.
- I think the last two breakers might be bad. I get 300-700 mV readings when I open them and check the voltage across either of their terminals. Thus even when I open them I can't tell what is on them. I plan to replace both of them soon.