Volt Meter Tester?

[bucs012]

I am learning more about electricity. I have a few outlet housings in my house that DON'T have any switch or receptical in them yet. The wires are there though.

I need to TEST the wires to see if they are getting power to them AND then find out which breaker it is to turn them OFF.

Can I use my automotive VOLT meter to test these outlets or do I HAVE to buy the specific tester for "electricity" at one of the big box stores?

Sorry if this is a dumb question but I am trying to learn.

 

[Stuart in MN]

If your meter has a setting for AC volts with a range of 120 volts or greater, sure. One thing to remember - if your voltmeter is a digital type, sometimes you'll see a 'phantom voltage': http://en.wikipedia.org/wiki/Phantom_voltage So, if you get a reading that's greater than zero but less than 120 it may or may not mean anything.

 

[D KRAGER]

If you have a multimeter (different settings, AC, DC ohms ect.), yes you can use it. Use the A/c setting 120 volt.

They also make a tester that you don't even have to touch the wire to see if it's hot, just get the tester close to the wire or box and it will light up. Very good for a beginner!


Don't use an automotive test light, you will blow it up!

 

[saabman]

The other thing to be mindful of is the color coding in house wiring is different than automotive wiring. For typical 110 volt house wiring look for:

Ground - Green (or bare wire)
HOT - Black
Neutral - White

You should see no voltage between Ground and Neutral, and 110 volts between HOT and Neutral and HOT and Ground.

 

[bucs012]

Great! Yes, mine has an AC,DC and ohms dial on it! I may also check into that NO TOUCH unit...........I don't want shocked!!!!!!!!!!!!!!!!

 

[bucs012]

The other thing to be mindful of is the color coding in house wiring is different than automotive wiring. For typical 110 volt house wiring look for:

Ground - Green (or bare wire)
HOT - Black
Neutral - White

You should see no voltage between Ground and Neutral, and 110 volts between HOT and Neutral and HOT and Ground.

My house is wired at 100amps and built in owa in 1983. I replaced a off/on swithch last night and in the outlet BOTH wires were black. Then there was a copper ground wire. I just put the new switch in, hooked it up like it was and it works.

I thought it was unusual to see BOTH wires as black.......

 

[D KRAGER]

Both wires on a switch will be black cause you are only switching the hot, not the neutral.

Sometimes you may see a white wire on a switch, but it should have a black piece of tape on it (not always). This happens when the power comes into the box with the light. No use running the neutral down to the switch, they just have to run the hot wire to the switch and back....

 

[saabman]

A switch is a circuit "interupter". Electrical "rules of engagement" say you interupt the power not the neutral/ground. So the switch cuts power feed to the light. Hot in, hot out when engaged.

Yes, tape should be used when repurposing a wire of the wrong color (it should be taped at both ends)

BTW, I am a Computer Engineer so I am giving advise based on my experience wiring houses and garages (and the learning I did to support that)

Chris

 

[tfi racing]

Just to be a bit safer,first turn off all the breakers!Then you can go to each box,pull the wires out so they are not touching the box or anyone(keep the pets and kids away) and strip a bit off(cap the ends with marrettes for an extra safeguard) so you can then test them.This way should reduce the chance of any arcing,sparking surprises.

 

[bucs012]

Great Ideas for me!

OK, so I take my volt meter tester and put the RED tip one on a wire. Then do I put the BLACK end to the ground wire? If there is no ground wire in the box what do I do with the black end of the testor?

Or do I put the Black end on one wire and the RED end on the other wire?

I have been scared of this **** my whole life and have pretty much stayed away from it! I am now 40 and need to start learning this stuff!

 

[Costner]

Set your meter to AC voltage and if it has adjustments set the range to accept 120V. Put the red lead on the black (hot) wire and the black lead on the white (neutral) wire. You should see 110-120V. Move the black lead to your ground wire (typically bare copper) and you should still see 120V. Move the red lead to the white wire and you should see 0V. Just don't touch two wires with your bare hands and don't allow the metal part of your test leads to touch. Basically just use common sense.

You shouldn't be scared of electricity - I've been shocked by 110V more than a few times and all it does is piss me off...it doesn't really hurt. I've been in situations where I could not shut off power so I just work with one line at a time. I've swapped receptacles and switches on live circuits and honestly it isn't a huge deal. Now if I had a heart condition or was standing in a puddle of water that might be a different story, but if you respect electricity and use your head it will be fine.

Frankly if you are just concerned about if a circuit is live or not, I second the recommendation to buy yourself a non-contact voltage tester. I use one of them all the time and you can buy them from any home improvement store. I think mine cost about $8 and when you put it near a live circuit it lights up and makes a chirping sound to let you know it is live.

Test it on a receptacle that you know is live to verify it is working - and then just take to the circuit you want to test and it should detect it. Shut off the breaker you think is connected and retest the circuit. If you have no power - then you know you're safe. However, I still like to test circuits with the voltmeter as a final precaution.

 

[D.J.]

I disagree with Costner, You should be afraid of (respect) electricity, it can kill you.
Yes I too have been shocked a few times and it pisses me off to. What if some goofball wired your house and has 240 on a set of wires? Be Safe an remember its the amps that kill you not the volts!
________
WELLBUTRIN SETTLEMENTS

 

[lametec]

I've been stung several times by 240V. It's twice the deal of getting stung by 120V, but still not the end of the world.

Once, as a kid, I stuck a cord in my mouth. Yup, it was still plugged in. 240V right in the mouth.

Not saying it can't be dangerous, but just because it's 240V doesn't mean it'll automatically kill you.

 

[Costner]

That was sort of my point. There is a difference between respect and fear. I respect electricity, but it doesn't scare me. If you are smart enough to know when you are over your head you won't have any problems - because sometimes you just need to let the pros handle it.

If you are just scared of it, that genearlly means you need to educate yourself, because if you plan to work around voltage you cannot be afraid. Confidence and fear are polar opposites, and you had better be confident if you plan to mess with wiring.

I've been fortunate enough to never have been hit by 240V or higher, but that is because I know when I'm working with high voltage circuits, I take even more precaution and double or triple check everything. While true the amps are what kill (or severely harm you) generally in residential wiring the greater the voltage the greater the amperage due to Ohm's law and the resistence of the human body remaining relatively constant.

 

[bucs012]

Thanks again for all the info, guys.

I FEAR it right now, but it's because I don't KNOW enough about it. That is why this thread is so helpful to me right now so that I UNDERSTAND a little more about it so that I can atleast try something.......Ha!

Don't worry. I will always RESPECT it enough to not get in too much trouble.

I have had my circular saw for years and used it many time. I still RESPECT that baby and think twice every time I use it. I know one WRONG move and I might be missing something!

 

[Chris Adams]

Your common VOM or Digital VOM (volt ohm meter) works dandy for testing A/C as has been posted, but if I was going to 'bug hunt' circuits I would invest in a cheap polarity tester and a cheap no touch pen.

For 5-6 bucks total at HF you can check polarity safely, watch out for hot wires without stripping or touching the wire, and do it quickly.

Those yellow cheap polarity testers with the three LED's are worth their weight in gold if you don't want to be pulling things apart and checking circuits.