I am probably going to be doing some wiring in my new house. I am obviously going to kill the breaker to the area im working on, but being the skeptic that i am, i want to test to see if its REALLY off. So, When checking with a volt meter set on "AC" does i put the red lead on the white or black wire of the home to check it??

 

Put it on both and the other to a known ground. But usually the black is hot if the house is wired correctly. You can also just plug a lamp or other electrical device in the outlet you are working on. That's what I do.

They make a pen type device that can check for voltage by just placing it next to a wire.

 

Lick your fingers and,,,,,, the pen type is nice emmits a nice chirping sound. Avail at most home imp stores for about $12. There is also a tester that will plug into an outlet to see if it is wired correctly, and can trip for GFI testing, most electrical inspectors use this. I have both but the pen type gets the most use.

 

NOTICE: ALWAYS ENSURE THE POWER IS TURNED OFF AND THE SOURCE! NEVER TAKE SOME OTHER PERSONS WORD, CHECK FOR YOUR SELF!

The following in a general guide and is only for reference. Codes in your area may differ or require other options or items. If you are unsure or unfamiliar with home wiring call a licensed professional to prevent injury, damage or death. Always check with the local authority for required codes and permits required before starting.

110/150v
Black is hot and goes to the Gold Screw/Terminal or the breaker.
White goes to the silver screw/terminal or the neutral block/bar.
Green or bare copper is the ground and goes to the green screw or the ground bar.
The neutral block or bar and the ground bar in a breaker box may be the same or 2 blocks next to each other.
Always rewire with a ground.

230v, 3 wires with ground or without ground.
Same as above with:
Red wire goes to the breaker and/or the 2nd gold screw/terminal on the outlet.
It may have a ground screw/terminal and a ground wire should be used.
If it is a 230v circuit, at the breaker box you should use double breakers not 2 single breakers. This is to prevent one side of the circuit from staying hot and the other cold without you knowing and being injured.

The best test device is a low coast indicator that plugs into the outlet and has lights to show: power, correct wiring and some will indicate low/high voltage.

Voltmeters will indicate power or lack of power but will not show correct polarity. It may or may not indicate a good ground circuit/wire. Both voltmeter probes go into the slots and generally it does not matter which color goes into a specific slot.

PLEASE BE CAREFUL!

 

Well, these wires are bare, there is no plug for them, so thats why i was asking. So you are saying it doesnt matter whether the red lead is touching white or black, and the black lead is touching the other?? I am comfortable with doing it, but i want to make sure there is no power to the wire, all i can do is kill the labeled breaker, adn then test with a voltmeter to be sure.

 

Are you referring to an old house that has “Bare” wires in glass or ceramic insulators or that the ends of the wires are stripped. If the wires are stripped on the ends then it will not matter which probe touches what wire.

The old bare-wire system is a completely different problem by tracking them down. But if you are at the terminal end of 2 wires (only 2 wires) then the same is true about the probe placement.

 

when testing at the device..(outlet, switch) this is the best proceedure w/ a multimeter.
1)red probe to black house wire-black probe to white house wire---should read 0volts. 2) black probe to house ground(bare copper)--should read 0volts. 3) red probe on white house wire-black probe to house ground--should read 0volts.(this makes sure there isn't a cross wired neutral that may be feeding back small volts.

 

I just use the red/black wires on multimeter to the black/white wires of the electrical circuit.

It either shows voltage present or doesn't.

I have the plug-in testor as well but without a receptacle I just use the multi-meter like above.

 

awesome. I will likely have an electrician for some more serious work, so they may end up doing this anyway, but maybe not.

Thanks for the info.