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My home built in 2016 has a pre-wired car charger line in the garage, I am trying to install a NEMA 14-50 outlet there.

Before I started, first thing I did was turning off the breaker to the car charger, then I used a non-contact voltage tester, which buzzed on both red and black wires, but not white or ground. I did some research and people were saying that those voltage testers are not very reliable and can pick up phantom voltages. So I bought a multimeter, and it showed 120-125V when I measured between red/black and ground.

What does this mean? Did the builder screw up the breaker connection, or is there something else?

My plan next is to have my utility company turn off the main circuit, wear class 0 gloves and install the outlet, then turn the power back on. Any problems with the plan?

Thanks in advance!

wires

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    Why would you need the utility to turn off power? Don't you have a main breaker? – manassehkatz-Moving 2 Codidact Nov 21 '20 at 23:21
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    Yes, don't you have a breaker you can turn the power off at? (It may be outside your unit, next to your electric meter) Also: you mean a NEMA 14-50 outlet, right? – ThreePhaseEel Nov 21 '20 at 23:24
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    If you turn off every breaker in your panel, does that shut this off? If so, then start turning on breakers one at a time (or 1/2 at a time - divide & conquer) until you find which breaker(s) control this circuit. For it to be wired to the "wrong" breaker is incorrect but certainly happens, particularly when wired but not terminated; to be wired straight to the main feed is a very bad and dangerous situation. – manassehkatz-Moving 2 Codidact Nov 21 '20 at 23:45
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    @wallyk Yes it is in California – Eric Nov 22 '20 at 0:12
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    Don't turn everything off first, turn breakers off one at a time until that circuit goes dead, . then, turn on the breaker you THOUGH it was connected to and see if it too was powering it. If so, you have two circuits crossed somewhere – JRaef Nov 22 '20 at 1:31
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Before I started, first thing I did was turning off the breaker to the car charger, then I used a non-contact voltage tester, which buzzed on both red and black wires, but not white or ground. I did some research and people were saying that those voltage testers are not very reliable and can pick up phantom voltages. So I bought a multimeter, and it showed 120-125V when I measured between red/black and ground.

Yeah, that's energized, alright.

Before I started, first thing I did was turning off the breaker to the car charger

That's where it went wrong. The panel labeling is wrong. (or remote possibility, the wiring).

There is no main breaker in the breaker box, there is a power shut off breaker outside my unit but it is locked by the utility company.

That's not legal, they can't do that! It is literally a Code violation to deny you access to your own main breaker, unless you are in a hotel or dormitory where supervisory staff is on-call 24x7 to reset it. And they know that and the power company has no "skin in the game" anyway, they have no interest in doing that to you.

I suspect you actually have a meter-main, which provides an outside main disconnect for the fire department's convenience. This will become Code when California adopts NEC 2020, but meantime, many municipalities already require it. This contains both the meter and the main breaker. It must by law have 2 separate compartments :

  • The meter compartment has a cover on which the power company can apply a seal.
  • The main-breaker compartment has a deadfront cover that bolts down, and keeps curious fingers out of the busways and terminations.
  • Since it's outdoors, there must be a weather cover covering at least the main-breaker area. This can be locked by the homeowner to stop pranksters. (the fire department has a master key).

So maybe you misunderstand how the doors work, and saw the PoCo seal on one part of it and thought it controls the whole thing. Perhaps the weather door is sticky or weird-to-open in some way. (some you lift the whole door straight up before it can swing, this is done to create a weather seal).

Otherwise maybe the weather door goes over the meter too, and the PoCo sealed it by mistake. Get em out there to fix it.

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  • Of course then there are the telco equivalents - Verizon sets up FIOS boxes with a customer-accessible compartment and a "Verizon only" section. The catch is that there are certain real-world situations where a power-cycle reset is needed and you can't do that (in some configurations) without opening up the other half. Which in theory would mean waiting on a truck run. For a residential customer. Late at night. When the customer just wants to get their internet working again. Easy enough to fix with a hex driver. Not that I would (cough, cough) know of such things. But no high voltage there. – manassehkatz-Moving 2 Codidact Nov 22 '20 at 1:02
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    So I called up my utility company, you are right, the door is not locked by them, it's actually locked by our HOA management company. Called their 24x7 line and they told me where they put the key. As I mentioned above, there are 4 double poles in my panel, stove, AC, dryer and car charger, the other 3 correctly turn off the corresponding circuit. Maybe the car charger is connected to 2 single pole breakers? I will try to turn off all breakers one by one tomorrow and see what happens. – Eric Nov 22 '20 at 1:12
  • Have you checked to see if stove, AC or dryer maybe also turns off the charger circuit? If you have all 4 off, do you get anything? Could be one wire on one circuit and one another (wrong, but possible). – manassehkatz-Moving 2 Codidact Nov 22 '20 at 1:40

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