Few very basic Electrical questions

Hi,

I bought a book plus spent a number of hours on the computer to research and I hope someone can help me with just a few very basic questions I still have:

  1. I have a 100 amp service. If I turn off the main circuit breaker can I change for instance a 20 amp breaker without worry of shock if I don't touch anything else other than the breaker and the wire that needs to be unscrewed? (I have a few that don't match my GE panel and I heard that they should)

  1. I had an electrician once run an extra outlet but in looking a few years later I see that he ran 14/2 cable after attaching this to 12/2 running off a 20 amp breaker. This line either powers a treadmill (runs on a "115 vac dedicated 20 amp {15 amp] circuit") or a iron. The receptacle is 15amp which I believe is fine with either, but should I swap the cable to 12/2 for safety?

  2. I also have similar to question two above (14/2, connected to
12/2) going to a GPF in a garage that the same guy did. Do they make a 20 amp GPF and should I switch the cable and the receptacle in this instance too?

  1. Can you run a series of five 15 amp receptacles for a workbench in an unfinished basement running on 12/2 on a 20 amp GPF breaker?

I really appreciate all your help!!

Best Regards, Steven

Reply to
SMF
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No license here so I don't have to cya.

  1. You should test it first with a simple tester but the normal answer is that all the breakers and everything below the main breaker is safe to touch with the main turned off. The juice stops inside the main breaker. The lugs above the main breaker are still HOT.

  1. I would because de-rating the wire is only allowed (or was allowed) when there is no possibility that it could ever pull more than it was designed for. Example: you wire a single light fixture with 14/2 at the end of a 20 amp circuit.

  2. I think they do at a premium price. I would most likely change the wire and leave the GFIC as it is.

  1. 20 amp circuits by code require 20 amp devices. There really is no defined limit to the number of devices. The 15 amp ones will most likely work fine and be safe but they are not "to code". Would I use them? Yes because in normal usage you are never going to pull 20 amps.

Your breakers must be rated and tested for the panel they are installed in to meet code.You may want to check the breakers before you go to the trouble to change them. They may be rated for your box. That said there are millions of breakers in boxes all around the world that do not meet that standard. The vast majority of them are perfectly safe and work as they should.

Colbyt

Reply to
Colbyt

Most people don't even bother to do that, but yes; the box should be dead if the main breaker is open. Never touch a potentially live wire without testing it first!

My breakers don't match my box. But if it bothers you, change them.

Yes, the cable has to match the breaker. If running a new cable is difficult, changing the breaker might be better.

I will guess that a GPF is a GFCI? It is fine to have 15a outlets on a 20a circuit, as long as there are more than one outlet. Yes, they make 20a GFCI outlets, but unless you expect to use a 20a plug, it is unnecessary.

Sure.

Reply to
Toller

Incorrect.

The NEC explicitly permits the use of 15A receptacles on a 20A circuit. See Article 210.21(B)(3).

Reply to
Doug Miller

I might add that you should check your "local" code as well. Mine for instance limits the number of devices (a receptacle being one device) on a single circuit to 10. As well, 15A receptacles on a 20 A circuit are allowed by the NEC but for the small difference in price, I'd just install the 20A recepts. Cheers, cc

Reply to
James "Cubby" Culbertson

You're suggesting that most people replace breakers without turning off the main breaker? Not only is that irresponsible to suggest to the OP, who clearly identified himself as a novice, but on what basis do you even make the claim that most people do it?

Reply to
trader4

English must be a second language for one of us; I don't see where I recommended that. I have no hard statistics, but I haven't spoken to anyone who turns off the main breaker so I expect it is the common practice.

Reply to
Toller

Thanks for the info Doug. All these years I thought I was cheating. I based my assumption on what I saw done in commercial installs. Some of that stuff might have pulled 17 amps on startup so I guess that is why they went with all 20's.

Colbyt

Reply to
Colbyt

Well, now you have. IMO, anyone who fiddles around with circuit breakers without turning off the main breaker is an idiot. I always turn it off. And I seriously doubt that most people don't turn off the main breaker.

Reply to
trader4

One more quick question and thank you very much for those that replied.

I bought a few ceramic ceiling fixtures (15amp) which I want to put in my basement to replace old existing ceramic ones. They will fit onto metal boxes. I bought the one which has a light socket with a single three pronged single receptacle on the side. This will attach to 12/2 wire on a 20 breaker.

Is this ok to do because I read somewhere that it is ok to have 15amp receptacles on a 20amp line once it is not a single (as opposed to double) receptacle. Also that it is not a single double instead of a series of doubles.

Thanks aga>Hi,

Reply to
SMF

That's like opening the breaker before unplugging your iron. But if you need to do it, there is certainly no harm, other than having to reset every electronic device in the house.

Reply to
Toller

It only gets worse. First, you claimed to a newbie concerned about safety that most people would not turn off the main breaker when replacing a breaker. I believe that is bogus, as most people, myself included would. And now you suggesting that replacing breakers without turning off the power is comparable to unplugging an iron?

Reply to
trader4

Geez, have you ever changed a breaker? You switch it off, confirm there is no power to the wire, pull it out, disconnect the wire, connect the wire to the new breaker, make sure the new breaker is open, shove the new breaker in. It is a hair more complicated than unplugging an iron, but neither more dangerous nor more difficult. Even if you forget to switch it off, it still should be perfectly safe since you don't touch the wire until the breaker is out of the box; even then it is with a presumably insulated screwdriver.

You should not come within 3" of a live wire, so where do you have a problem? And even if by some bizarre accident, worst came to worst, unless you are working barefoot standing in salt water... Do you wear rubber gloves when you do it, just to be sure? Stand on glass jars? Have one hand behind your back? Maybe pull the meter? Geez.

Reply to
Toller

Well, you're seriously wrong. I've done my own electrical work for years and have worked on electrical projects with numerous other people, both residential and commercial and I've yet to run into anyone who shuts off the main when changing branch circuit breakers, including removing / installing bolt on breakers (Insulated nut driver and gloves of course). The snap in breakers that are the norm in residential and many commercial installations are specifically designed to be easy to remove and install on a live bus.

Pete C.

Reply to
Pete C.

Have to agree. The normal snap in breakers are very much comparable to a regular 5-15 plug connection.

You are holding an insulated breaker case equivalent to an insulated plug, and you are connecting / disconnecting a spring pressure connection just like a plug.

All is at the same voltages you get with normal plugs, even with a two pole breaker since 6-20 and 6-30 and 6-50 plugs are common household items as well.

If you feel better turning off the main then by all means do so, it's only your time to reset everything that you're wasting, but don't insist that everyone else should do the same.

Pete C.

Reply to
Pete C.

Well, the OP, who's an obvious novice, doesn't have to listen to any of us. He can just do a simple google search for "replacing circuit breaker". There are plenty of websites with info. He can see what they recommend doing. And I'm sure he'll find that virtually every one of them has turning off the main breaker as the first step. Then he can decide what he thinks most people would do and make his own choice.

Reply to
trader4

Right. But no one sugested that.

Reply to
Toller

But, at least at transmission voltages, you (usually) have enough advanced warning that you're getting too close before anything bad happens. Nothing like a low current streamer off the elbow to remind you.......

Reply to
Bob

Hi, First, don't get caught up with numbers too much. How many times do you think 15A outlet will draw full 15A constantly when a device is plugged in? Breaker is safety device, when things are not right, it'll trip. Electrician did the wiring few years ago, ever breaker tripped? Ever had trouble? What does it say? Within the code, common sense prevaials. Knowledge without experience is useless or even dangerous. Catch 22, you gain experience by doing......

Reply to
Tony Hwang

While I see your point -- I would consider it irresponsible to suggest to a NEWBIE that it would normal for them to replace a bkr in a panel without throwing the mains off.

I've worked bare-handed on 345kv lines but I sure as h wouldn't recommend it to the in-experienced.

BTW, I tend to believe in Murphy's law and when I've done work on panels I shut the main off.

Reply to
Jay Stootzmann

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