Stupid electrical question

[Bob Childress]

Well, I've always turned off the breaker whenever I'm working on a circuit, but it just seems to me that if you are changing, for example, a switched light fixture, just turning off the switch (and taping it in place) would be sufficient and much easier. But the common wisdom seems to be to turn off the breaker anyway. How come? Am I crazy (I mean in this case), and if so, why? :confused:

[Tyler Howell]

Always at the breaker especially if you're not dead sure how it was wired. For many years and even today some "home handy persons" will switch the neutral line to control a circuit. It may still be hot and you become the final conductor to permit current to flow.
Also several boxes may have more than one circuit running through them.
CYA:mad:

[Ken Fitzgerald]

Always at the breaker especially if you're not dead sure how it was wired. For many years and even today some "home handy persons" will switch the neutral line to control a circuit. It may still be hot and you become the final conductor to permit current to flow.
Also several boxes may have more than one circuit running through them.
CYA:mad:

I work with up to 160 KV dc daily and 3 phase ac.........Tyler's advice is awfully SAGE! and SAFE I might add! I've been working on high powered electronics since 1970. I've only been shocked a couple of times.....and only when the alignments required the system be energized.......Take Tyler's advice!

[Bob Childress]

Okay, I'm sold. :D Just wondered and Tyler explained it. Don't need any surprises. :eek: Thanks.

[Kent Fitzgerald]

In addition to what Tyler mentioned....

If there's a load on the circuit, and you disconnect the upstream neutral, the white wire is now hot. People tend to assume that the neutral is "safe," but you have to remember that it's a current-carrying conductor, which means it has the potential (pun semi-intended) to deliver a dangerous shock.

[Bob Childress]

Ken,

I know you are right. I believe what got me to thinking about it was the electrician I had out here a while back to put in an outlet under the cooktop. I offered to turn off the breaker and he just said "Doesn't matter" and kept on working. I can remember my Dad doing much the same thing years ago, "just keep the wires from touching and don't touch but one at a time." :D

[Tyler Howell]

Bob,
There are old electricians, and bold electricians but few old bold ones.
110/120 doesn't seem like much but that is what takes more people out then anything else.
There are some times a pro will have to work hot. They have the tools and the training (not always the common sense) to do so.
Good Luck ;)

PS I sent employees home for not shutting off a system at the source:mad: . Cost him a 1/2 days pay and put others at risk.

[Matt Warfield]

And even if you are dead sure you know how it's wired, turning the breaker off will prevent someone who is unaware to give you a sudden surprise when they flip on the switch. I would say always flip off the breaker but then I'd have to listen to my own advice.:rolleyes:

[Mark Pruitt]

There was an incident here recently where a man was working on a light fixture with the power turned off only at the wall switch. Someone came into the room and, not knowing what the man was doing, turned the switch on. The result was hospitalization due to heart damage.

It's a pain in the butt to have to go find the right breaker and turn it off, but it's a lot easier than a trip to the ER (not to mention a lot less expensive).

Mark

[Peter Stahl]

Even after turning the breaker off check it with a meter. My first house had 2 circuits sharing a neutral and the circuit I had off still showed some current. My uncle was a good one for changing a switch with the power on, he arched a couple screw drivers. He was a electrical engineer who had little hands on experience. Work safe, turn the power off. Always double check your connections before turning it back on especially when wiring dimmers, they can short out easily, DAMHIKT!

[Rob Russell]

There are other reasons to kill the circuit at the breaker.

The fixture you're swapping may be controlled by a 3-way switch and, if you don't know that, it means there's another switch that can turn the fixture on while you're working on it.
It's also quite possible that the power is fed to the fixture and then out to a single switch. Killing the switch just turns the light off - the hot conductor back at the fixture is still energized.Rob

[Frank Fusco]

Glad I read this thread. I am pretty electricaly uninformed. But I can and do change fixtures, etc. With a light fixture I have just turned off the switch. From now on it will be the breaker. Thanks, y'all.