Okay, I read the whole thread, but I’m still confused as to why we have to wait until Thursday to figure out what’s going to happen! 
Oh yeah, and I vote for turning off the breaker also.
OK, for a realistic shorter term fix, figure out which breaker is connected to this outlet, and when you leave for your trip, flip the breaker. Turn back on when you get back. Until then, you only notify the landlord about the problem, and you don’t do anything like cut the plug off.
I was discussing this with my husband tonight, and he was in the “grab the cord and give it a good yank” camp.
Won’t hot/hot result in 0 current flow (if both are the same phase)?
What meter did you get? I don’t think a clamp ammeter will work with normal cables, since both directions are together. I personally have a kill-a-watt style device.
You’d have to split the outer jacket of the cord and clamp around one of the conductors, but you could do it without unplugging anything.
Re: installing the lock on the outlet
The contractors, if they are not going to break the outlet open, should just use another outlet and maybe a longer extension cord, it is really a non-issue. It is not like they are going to be justified billing standing around that single outlet praying that the gods open it up.
Clothahump, don’t alter quotes, for any reason.
They are not the same phase if you use a dryer receptacle. That’s how you get your 220 Volts.
Aren’t almost all appliances these days dual voltage? Here in the UK, the mains voltage is 230V. Unless appliances are specially designed for America’s weak-ass power supply (:p) they should be able to handle a proper voltage.
If the OP is going to be out of the home for a month, then DEFINITELY turn off the breaker.
Fantasy revenge answer : hook up one of these to the offending circuit. Energize liberally. Anything more complicated than a toaster would be, well, toast.
Boring, reality-based answer : call the cops, landlord and the utility company after taking pictures and video of the evidence.
Nope, not that I’m aware of. You Brits use that slow-ass 50hz power, right? 
Unplug the extension cord and plug it into 240 VAC. (You will need to make an adapter to do this.)
And then sit back and watch the fun.
That’s what I said a page back! Would be fun to watch!
That’s irrelevant.
It’s the fact that a current clamp needs to be clamped around only one conductor. Forget “phase” - the clamp reads magnetic fields, and so the feed and return line must be separated, because their magnetic fields cancel. So, if you try to read the current in “lamp cord” you will get zero, because both the feed and return are being read together.
BTW: this is how a GFCI works - it reads the current in both the feed and return - if it’s not zero, current must be going somewhere it shouldn’t - like into a ground fault.
Thursday! no way, live balcony cam and someone goes the fuck up there and see what is plugged in.
i don’t do “delayed gratification” !! :mad:
Which are not the same phase:
110 vs 220
220 vs 220
?
Because 110 vs 220, will still give you about 110V difference, unless it’s 180 out of phase.
And I can’t see how 220 vs 220 will be out of phase, any more than 110 vs 110 will be out of phase.
Wow. Nobody suggested that so far. :rolleyes:
I say notify the landlord.
Is this a multi-unit complex? Have you looked to see that you’re the only one he’s plugged into? Wondering if he might be draining power from multiple locations…
I have to admire SenorBeef. I would never have the restraint to not unplug the thing,pull it down and go pounding on the neighbor’s front door with the evidence.
Thursday? Couldn’t he even pay the extra $3.99 for the overnight Amazon Prime shipping? Geez.
In the US, a house is wired to a secondary winding on the pole mounted transformer that provides ~220 volts from end to end. This winding is center tapped, and that center tap is also tied to earth. From the center tap to either end of the winding will measure ~110 volts; From end to end measures ~220 volts. So about half your 110 devices are 180 degrees out of phase with the others.
If you put one side of a meter to the “hot” of one 110v outlet and the other side to the “hot” of an outlet wired to the adjacent breaker, you will measure 220v.