Key piece of info. I think you are on the trail.
Ah. Perhaps this was less construction expedience and more surplus to requirements and decommissioned in place when the sales office was demolished and power was needed for other major appliances purpose such as the dryer or oven.
I wouldn’t be surprised if it powered a stand-alone HVAC unit (or two) for garage/showroom area during sales phase.
That, or external lighting, or both.
I am a Master Electrician for reference. Haven’t read through all the emails above. BUt that looks like what we typically use for a disconnect to an electric heater or an AC/Heat Pump Unit. Could also be for a pool, or hottub, but those are typically with a GFCI breaker, although that could be in the main panel. Then again it could be serving power to any number of things. It’s not a specific use piece of equipment. Could even have a neutral conductor in the wire run and you have 120 volts there as well between each phase and the neutral. The breaker in the box may not even be an actual breaker, it possibly could just be a switch for on/off. Sometimes they have real breakers and sometimes they don’t. I’ve had them come both ways. You’d have to follow the wires to see what it actually controls.
It’s a switch (as indicated by both the panel label and the device proper), seemingly in a standard double-wide 240V circuit breaker formfactor which I’ve often seen used as a disconnect as you describe.
yup you’re right. Blow up the photo and it says “no over current protection provided”. You can replace that switch with a breaker though if ever needed. not that you should since the nameplate on the can says unfused switch lol. I’ve installed disconnects like that both ways. Some are blank and don;t have the name plate. Some of the switches that look like breakers don;t have the no overcurrent protection stickers either. Gotta take them out and inspect for factory lables. But yea, the label on the switch says it all. it’s just a switch. good eye!
use a pair of dykes / side cutters and cut the wires and see what doesn’t work after the fact…yes i am joking
Have you checked the label on the main panel?
It’s likely fed from the main panel. Perhaps there’s an item listed on the label that doesn’t make sense (like hot tub, if you don’t have one).
For most part, main (only) panel is labeled OK…some of the breakers are labeled one thing but then also control something else on the same circuit, e.g. labeled “kitchen can lights” but also controls the countertop outlets. But nothing I would consider unaccounted for.
Subsequent monkeying around by me has left me convinced that there is no voltage or current leading into or out of box, including when switch is on. IMO is almost certainly a vestigial/abandoned circuit for use when house was used for sales/show during builder/subdivision development phase.
I was going to say like Blatz Cave
Clark Griswold’s Christmas light display.