110v In Bare Wire?

[rissa]

So i'm replacing an outlet in my garage. It has power coming from a switch to turn on a light. With switch off the bare wire ( which i've always thought of as a ground wire) has constant 110 thru it according to prong tester and the black wire has 220 when switch is on. This outlet was formerly used for garage door opener which i'm sure needs constant power. Help- i'm lost.
ps- getting an electrican out here is next to impossible. Thanks.

 

[djjsr]

the black wire has 220 when switch is on.

Are you in the U.S. ?

 

[rissa]

yes i am.

 

[kursplat]

is this an attached or detached garage? since you said "bare wire", is it romex? any other wiring in the garage? do you know which breaker or fuse feeds this? have you id'd that feed and turned off all the others? you said you used a "prong tester". so it's the plug in style to check the wiring is correct? do you have access to a wiggy or a meter?

 

[rissa]

attached garage. it's the bare wire in 12/2 romex. it is a prong tester- it just broke so i'm off to buy a wiggy.

 

[mds5951]

Wtf is a prong tester?

 

[Kevin54]

attached garage. it's the bare wire in 12/2 romex. it is a prong tester- it just broke so i'm off to buy a wiggy.

Wtf is a prong tester?

WTF is a prong tester? I'm thinking WTF is a WIGGY

 

[rissa]

whoops it is the white (neutral wire) that has the power...

 

[Kevin54]

So i'm replacing an outlet in my garage. It has power coming from a switch to turn on a light. With switch off the bare wire ( which i've always thought of as a ground wire) has constant 110 thru it according to prong tester and the black wire has 220 when switch is on. This outlet was formerly used for garage door opener which i'm sure needs constant power. Help- i'm lost.
ps- getting an electrican out here is next to impossible. Thanks.

If you have 110v coming through the bare wire, which IS a ground wire, then someone has taken some shortcuts with the wiring. Also, I've never seen a 220v garage door opener. Can you trace things back to the breaker box? If you can, then I would disconnect things before things go south. If you have to pull a new wire, then I would do that. When you wire in a switch, all you should be doing is breaking the black wire which is your hot wire. The neutral will be connected together to make a continuous run, and the ground (your bare wire) will be hooked to your ground lug.

If the ground is running 220v, then you may want to pull all of your outlets and pull any lights you have to see if they are hooked up correctly before a possible fire happens. With your wiring, if it is 12-2 with ground, you'll have a white, black, and a bare wire which is your ground. If you have 12-3 with ground, you'll have black, white, and red, and the bare wire will be ground. You don't want current running through your bare wire.

One other thing...when you check the current with your meter, where are you putting your cable leads? IF you are putting a red lead on a wire and your black lead on your bare wire, you will be reading the current that is traveling through the sheathed wire. If you are putting the red lead of the meter on to the bare wire, and the black lead onto an Earth ground, then you actually have current running through the bare or ground wire.

Can you snap any pics of what things look like in the box you're working on?

 

[rissa]

hi, it seems that when my house was built (1978) the electrican must have run short on wires- i found whites going to blacks and vise versa. one bare (grd) was made hot???. i'm redoing all the garage wiring. thanks guys.

 

[mds5951]

... It wouldn't happen to be a 3 way switch?

 

[MyTechGuy LLC]

WTF is a prong tester? I'm thinking WTF is a WIGGY

LOl...

If anyone lives by a harbor freight then why spend money on a wiggy when harbor freight gives meters away for free?

hi, it seems that when my house was built (1978) the electrican must have run short on wires- i found whites going to blacks and vise versa.

Sometimes a white will be recoded to a black and the (cough, cough... lazy) person who did it didn't mark the white as a recoded black. A true white to black would be a shorted circuit.

Listen to what Kevin said.

THIS might also help.

 

[rissa]

thanks!

 

[pattenp]

If you are testing wires in the switch bot and can get a 220V reading then there is possibly a multiwire branch circuit to that box. Testing any hot wire to the ground wire will give you 110V. Testing across 2 hots which are on different legs in the panel will give you 220V. Other than that I don't know what's going. I doubt very much that you have a hot ground.

 

[Jaspel]

When you say the bare(white?) wire is 110, what is the other probe hooked up to(referencing)? Sometimes neutrals will be interconnected to other circuits outside of the panel. Shutting off all breakers other than the one you are working on may help.
It can be hard to tell if the meter is showing a low current voltage or a realistic one if there is no load.

 

[wyliesdiesels]

Wtf is a prong tester?

WTF is a prong tester? I'm thinking WTF is a WIGGY

By prong tester Im guessing he's referring to one of those plug in outlet testers with the 3 lights- 2 orange and 1 red. It has a color code chart to tell u if the outlet is wired correctly.

A Wiggy is a solenoid style voltage tester! They're similar to the fluke T5 line of testers but have a simple indicator dial instead of a digital readout!

 

[BFBOB]

DMM's (digital multi meters) can give you false readings when testing house wiring. The reason is they are too sensitive in some cases. A real-world case is trying to troubleshoot a light that doesn't work. Bulb is good (tried it in another fixture), DMM read 121.3V at the fixture. No light. With much laborious wire tracing, the problem turned out to be a splice that was good mechanically, but had corrosion. Shined up the wires, new wirenut, and all was well.
The point is that a DMM requires so little current to get a reading that the high-resistance splice dropped practically no voltage, and the meter read normal. A Wiggy (yes, that's the name the manufacturer gave it) and its bretheren use a different measuring method that pulls way more current - enough that in this situation it would read some voltage, but very low. That reading tells you what to look for- a high-resistance connection.
The plug-in testers have the same weakness as DMM's. They are low current solid state devices that are really only good for spotting miswired outlets - reversed hot and neutrals for instance.
I use my DMM all the time on house wiring, but I keep firmly in mind that its limitations may cause false readings.

 

[raddksn]

The original "WIGGI" was made by Wiggington manufacturing.

 

[wyliesdiesels]

So i'm replacing an outlet in my garage. It has power coming from a switch to turn on a light. With switch off the bare wire ( which i've always thought of as a ground wire) has constant 110 thru it according to prong tester and the black wire has 220 when switch is on. This outlet was formerly used for garage door opener which i'm sure needs constant power. Help- i'm lost.
ps- getting an electrican out here is next to impossible. Thanks.

The white wire and black wire have 120v and 240v in reference to what other wire? If u test a white and black wire in a normally wired line to neutral 120v circuit, then the reading should be 120v. If the white and black wires are instead both connected to opposite legs in the panel, then u would get a 240v rating and that just means someone forgot to tape the white wire black. Based on your description, that sounds like what u have going on.

If u can take some pics and post 'em here that would be helpful!

 

[eljefino]

Follow the wire back to the breaker (s) and see what's going on in the main box. I wonder if someone wired up "redneck 240" to "instantly double the power in the garage."

Do you or did you ever have any hot water heaters, dryers etc in the garage as an excuse to have 240?