Electrical Safety

dzirkelb

Member
When installing a new outlet or a new dimmer switch, what pieces of hardware do you use for testing the power lines to ensure they are off? I don't wanna get zapped :o
 
When installing a new outlet or a new dimmer switch, what pieces of hardware do you use for testing the power lines to ensure they are off? I don't wanna get zapped :o
You could try one of these -

http://www.thinkgeek.com/stuff/41/lebedev.shtml

You could also go to the home depot and walk down the electrical isle - .99 cents will buy you a basic neon tester.

Remember - wiring outlets is not for amateurs. Consult a real electrician before proceeding.
 
Something like this or even a simple test light works great. Touch the probes to the + and common wires - if the light comes on then there is power. If it stays off, then the power is off. Simple as that.

Here is a picture of the test light I use.
GENCT101.jpg
 
Remember - wiring outlets is not for amateurs. Consult a real electrician before proceeding.
Back in the 70's I worked for an electrician that would lick his finger to [then] test current flow.

If you don't have a friend or relative that can teach you a bit about wiring... maybe Home Depot will cover what you need in one of their Saturday morning classes. They also have some handy reference books with instructions too. A short class in how to fish wire... can change a persons life.

These are skills that can be learned. But don't try to wing it... ether take the time to learn what your doing first.. or walk away. Wiring errors can have fatal consequents.. years or even decades later.
 
Touch the probes to the + and common wires - if the light comes on then there is power. If it stays off, then the power is off. Simple as that.

I am not so sure thats correct. Here at my house (an older home) I use AC. The AC stands for alternating Current. Which means the + and - aren't like the DC (Direct Current) examples we we had in grade school. So if my old wiring uses a switch to break the (+) black wire.... I might still get a nice jolt off the white (-) wire... if I happen to be grounded.

A very common cause of shock at home is messing with a light when the switch is switched OFF.
 
Touch the probes to the + and common wires - if the light comes on then there is power. If it stays off, then the power is off. Simple as that.

I am not so sure thats correct. Here at my house (an older home) I use AC. The AC stands for alternating Current. Which means the + and - aren't like the DC (Direct Current) examples we we had in grade school. So if my old wiring uses a switch to break the (+) black wire.... I can still get a nice jolt off the white (-) wire... if I happen to be grounded.

A very common cause of shock at home is messing with a light when the switch is switched OFF.

Good point. The best thing to do is to turn the breaker off whenever messing with outlets and switches. If you are unsure which circuit breaker a specific outlet or switch is tied to, they make detectors for that too.
 
My wife's cousin is an electrician...I just wanted to start here so I didn't sound too dumb to him about checking power.

And, always flip the breaker before working on anything :) I just flip until it turns off the power I am trying to use, that is, if the breaker is not labeled.

I wasn't sure if the power outlet testers would work the same for light ones...the power outlet ones I have always used are the ones with a white tip that you sort of shove in the outlet, and it beeps if live.
 
I wasn't sure if the power outlet testers would work the same for light ones...the power outlet ones I have always used are the ones with a white tip that you sort of shove in the outlet, and it beeps if live.

For any electrical noob that stumbles in this thread later: the referenced tester works by induction (google "inductive voltage detector") and can be used for any wiring circuit, not just an outlet... If you can get next to the wiring bundle (typically 1/2" or so) and it beeps/buzzes, it's hot. Ergo, you need to turn the breaker off before you touch those wires.

Preachy note: There is nothing so critical in a residential situation that requires you to work on a live circuit. Please take a sane route and walk to the panel to flip the breaker off before attempting any work.
 
I would tend to also try to figure out what circuits go to what plugs. It's handy so you are not killing every circuit in the house looking.

I made a map for the last house I bought. I basically turned off one circuit, then walked around plugging in a lamp, then marked what circuits went off.

On my new house I have the plans.

--Dan
 
Another tip - let your wife/sig other know when you flip a breaker, or better yet, put a piece of masking tape across the breaker box.
 
always, always flip the breaker, I definately agree!!

one other thing to be on the lookout for: while less common in residential, an electrical box could have more than one circuit running through it. After you flip the breaker, always double check with the tester to make sure you have killed all circuits that you might come in contact with.

Nick
 
I just use one of those inductive testers. They are easier to use than the contact ones, and if you have boxes that have multiple circuits running into them, it's really easy to check if the switch you are working on is live or not, and checking for power in the rest of the box.

My electrician guy works on everything hot. I think he's borderline crazy, but he is FAST. He installed 19 can lights in 2 finished rooms, fished the wires, and installed 2 extra switches in my old house in about an hour.
 
.... My electrician guy works on everything hot. I think he's borderline crazy, but he is FAST.
He's not crazy. About 35,000 people die driving to and from work each year... we learn to accept limited risk.

Electricians might risk a little shock.. to save a lot time. But they don't risk electrocution. If you watch your friend work you will see the insulated tools in one hand. If he does take a shock it will be in his [other] left hand. It won't cross through his heart... by going from hand to hand. The electrician I worked for also worked hot. And back then... so did I. I rarely work with live wires anymore... but I still handle every light or receptacle or loose wire as if it IS HOT.

If I touch a live wire by mistake.. and take a shock or burn.. it will be to my left hand. Whereas I have nothing against my left hand... as we used to say.. I sign my checks with my right hand. (meaning a burn on my left hand wouldn't cause me any lost wages).
 
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