last day (15 days later) » 

05:12
5
Q: Electric Bill Serious Spike (Possible Wire Damage)

Taimy brother and I recently started a project to build a patio over a jacuzzi to protect it from snow, and this requires drilling holes in concrete for anchor bolts for the posts. After we started, the next electric bill he received was around 600% increase (from 120 to 800), and 12 days since, the...

So turn off the breaker(s) associated with the area and look at the meter to see if it stops using so much power when you do that.
Mostly agree with @Ecnerwal but I'd turn off ALL the breakers and turn them on one at a time and observe the meter to see which circuit is causing the excessive usage.
so what is not working
Is the hot tub heater running more than it should?
Does the rise in the electric bill correspond to powering up the jacuzzi? I realize this is obvious, but those things soak down a lot more power than most people expect. Especially if left uncovered.
05:12
Has a neighbor started to steal electricity? any extension cables plugged in?
Tai
Tai
We have never turned on the hot tub since we got the house, so it's never in use, and I have not seen any cables or anything from neighbors. They did just build a brand new house next door, but I don't know if that could cause a serious issue with our power somehow.
Would try Georges suggestion of turn all breakers off. Might be the new roof and high power just happened at the same time. Unless you have outdoor outlets/lights pass the patio, wires under the floor seems unlikely.
Rob
Rob
Take the cover off your panel and put a clamp meter on each wire going to breakers to see what circuits are using a lot of power. If you don't know what i'm talking about, hire someone. It can be dangerous if you don't know what you're doing.
"They did just build a brand new house next door," - was there a post put into the ground with a meter hung on it before they started? If so it wasn't them, if not then they're highly suspect. If you're not concerned with the pipes freezing and you have the HVAC off, then drop the main breaker when you're not there. Which you should be doing anyway if you suspect damage and you're not there.
Locate the breaker (or breakers) associated with the mystery switches, shut it off (verify that hot boxes stay cool and power meter does not wind up if you flip the switches) and unscrew the covers of the mystery hot boxes, and post pictures (probably as a new question linked to this question, not a further extension of this question.)
05:12
Side walk melter; that's why they're two 20a switches and get hot, and used liquid tight.
With your EDIT 2, I see two boxes, but the covers are on them, so they are generic. Would you mind taking and posting photos of the boxes with the covers removed?
Why was my comment immediately suppressed??? It seems pretty relevant.
Those boxes remind me of connection boxess I've seen to resistance heating beneath a concrete driveway, to keep ice melted.
Great work isolating it down to these two boxes. Now I'm absolutely dying to know what these mysterious boxes are for. Please don't leave us hanging !
@SteveSummit I don't live in the snowy areas, but is $800/mo cheaper than shovelling one's driveway? Ice takes a phenomenal amount of expensive energy to melt.
@Criggie I don't know how much it costs to run those ice-melting heaters. I live in Cambridge, MA, and there's one just up the street from me, on a steep, curving driveway. You always get some ice on a driveway, because someone always drives on the snow before you have a chance to shovel it, and when it's sloped, ice makes it absolutely impassable. So while I wouldn't pay for those heaters, I can see why some people do, even though it's an expen$ive luxury.
@Criggie they aren't supposed to be ran continuously. They should either be on a timer or a have some kind of sensors that control them. See e.g. this

last day (15 days later) »