adding 20 amp circuit to residence

It was an electrician who told me about not exceeding the amperage rating of the panel, he's also the one who said that it was pretty unusual (but not impossible) for everything to be turned on at once and thus overload the panel. That could trip the main breaker but if it just got close and didn't trip it it could overheat the feed wiring going to that main breaker, which is bad news.

It is true that it's amps that kill, not volts. The description of a 220V circuit is exactly correct. It's also much more likely to kill if you manage to get hold of both legs at once accidentally and you also have the bad luck to be well grounded at the same time. Me, I have a high respect for both and do my work when I have determined that the circuit is dead. I have in the past worked on live 110v (not very smart) and gotten bit. I won't work on a live 220v circuit.

I've done a lot of my own electrical work (hung many a ceiling fan and light fixture, replaced all the switches and outlets in this house, run extra circuits for a garage at another house, wired a garage from scratch including 220v for compressors and A/C, replaced motors in HVAC air handlers, I could rattle on for a while) and am still here to tell the tale. I must have done something right.

Story told to me by a bud: he used to be the night manager for a McDonald's. The store was one of a small chain and the owners had hired a guy as their repair guy, he did electrical/sheetrock/etc. My bud was overseeing things one evening, the big sign out front was on a photocell so it would come on at dusk and it did. The light came on, stuttered a little bit, he heard a 'bang' and the sign went out. He runs back into the rear of the restaurant, the handyman is laying on the floor clutching the burnt off remains of a screwdriver and has burn marks all over his face. He had let himself in with his key and was fishing around in the breaker box when the sign came on, it was his bad luck his screwdriver was in the wrong place when that happened.

Curmudgeon wrote: It was an electrician who told me about not exceeding the amperage rating of the panel, he's also the one who said that it was pretty unusual (but not impossible) for everything to be turned on at once and thus overload the panel. That could trip the main breaker but if it just got close and didn't trip it it could overheat the feed wiring going to that main breaker, which is bad news. It is true that it's amps that kill, not volts. The description of a 220V circuit is exactly correct. It's also much more likely to kill if you manage to get hold of both legs at once accidentally and you also have the bad luck to be well grounded at the same time. Me, I have a high respect for both and do my work when I have determined that the circuit is dead. I have in the past worked on live 110v (not very smart) and gotten bit. I won't work on a live 220v circuit. I've done a lot of my own electrical work (hung many a ceiling fan and light fixture, replaced all the switches and outlets in this house, run extra circuits for a garage at another house, wired a garage from scratch including 220v for compressors and A/C, replaced motors in HVAC air handlers, I could rattle on for a while) and am still here to tell the tale. I must have done something right.

You better have, cause if my shop burns down, I'm coming for you...

Lowe's has a book on home electrical repair/remodeling. If you're not skilled with teh electronz, you might pick the book up first.

In reply to Toyman01:

You won't if it burns down the right way.

I appreciate ALL of the advice. That's why I post here. Since you brought it up (and how could I fail to mention this, it was in all the tutorials) there is ample room in the box. I have also wired ceiling fans from regular light fixtures, even upgrading the box properly. This is definitely a next level project because I've never delt straight with the box innards. This is why I ask. I can read all the books and the tutorials yet still miss tips tricks and other stuff I need to know that comes out way more raw and real from your minds directly to the keyboard. So again I say thanks!

Hess mentioned the Lowe's book, I have the Black & Decker version which I bought to try to figure out 3 way switches. (I swear those things have voodoo inside.) It's a good resource for things like wire gauge for a given amperage etc. Definitely worth the $ spent.

In reply to Toyman01:

Sounds like we agree. We both think it is a reasonable skill to learn, we both think most people on this board can do it.

You suggested a book. I suggested he ask for help. Sounds like we both think he may need a little help.

I have the book you linked. It's is big on theory, but VERY light on technique. I think that technique is easier to learn from a person, but it doesn't really matter.

BTW, there is a quote in that book... "Never attempt an electrical project beyond your skill or confidence level". I agree with your book, but think only gunner can make that assessment.

gunner wrote: I appreciate ALL of the advice. That's why I post here. Since you brought it up (and how could I fail to mention this, it was in all the tutorials) there is ample room in the box. I have also wired ceiling fans from regular light fixtures, even upgrading the box properly. This is definitely a next level project because I've never delt straight with the box innards. This is why I ask. I can read all the books and the tutorials yet still miss tips tricks and other stuff I need to know that comes out way more raw and real from your minds directly to the keyboard. So again I say thanks!

honestly, working inside the main panel is easier than working in a 3 gang box with a big fat gfci, a couple switches, and 8 other wires because the builder grade electrician decided to use that box as a junction for half the house.

i was intimidated at first by main panels. then i realized how silly it was for me to wait for an electrician to come to my job to run a couple wires, or put in a new breaker, and slow my work down. so i worked with that electrician for a couple days on my jobs to learn how to do the things i was needing done correctly. he loved that i wanted to learn so he didn't have to do partial day small jobs here and there for me, and i got to learn from a very highly regarded pro.

i disagree that 90% of hack jobs are done by "professionals" it's 50/50 homeowners to pros for hacks, but unfortunately it seems that 90% of "professionals" are hacks. probably 90% of homeowners too, at least in my experience. maybe more.

I ran a 240V circuit for a buddy's asymmetric lift (lucky bastard), IIRC it was a 30 amp, more than enough to kill. The actual running of the wire wasn't difficult; we pulled the wire from the lift through the conduit, put all that in place then as the last step pulled the wire through the box conduit. We left the box live so we'd have lights etc up to the time we pulled through the last piece of conduit, we cut the main breaker, opened both rollup doors and used flashlights as we did that last step. We both survived and the lift works.

gunner wrote: I appreciate ALL of the advice. That's why I post here. Since you brought it up (and how could I fail to mention this, it was in all the tutorials) there is ample room in the box. I have also wired ceiling fans from regular light fixtures, even upgrading the box properly. This is definitely a next level project because I've never delt straight with the box innards. This is why I ask. I can read all the books and the tutorials yet still miss tips tricks and other stuff I need to know that comes out way more raw and real from your minds directly to the keyboard. So again I say thanks!

This is well within your capabilities, with one possible exception.

Many (most?) panel boxes do no have a service disconnect. That means you can't kill the power in the panel box.

If your main breaker is in the panel box, the box is hot.

If you have a 2nd main at the service entrance, or a disconnect, you can kill the power there.

Otherwise, the only way to kill the power is to pull the meter. If you pull the meter, you will have to break the power company's security lock. You will have to have them re-install it.

The busses in the rear of the panel box are hot, and anything that touches them (pliers, hands, stray wires, etc.). They carry THE FULL CAPACITY of the panel box.

I work in hot panels regularly, but can't recommend it.

SVreX wrote: In reply to Toyman01: Sounds like we agree. We both think it is a reasonable skill to learn, we both think most people on this board can do it. You suggested a book. I suggested he ask for help. Sounds like we both think he may need a little help. I have the book you linked. It's is big on theory, but VERY light on technique. I think that technique is easier to learn from a person, but it doesn't really matter. BTW, there is a quote in that book... "Never attempt an electrical project beyond your skill or confidence level". I agree with your book, but think only gunner can make that assessment.

Agreed.

I know I probably shouldn't, but I do know enough about juice to do some stuff on my own. If you're just adding a 20A breaker, go for it. Use 10-2wg for longer runs, but 12-2wg will be adequate for short runs. Use your noggin and its really no different than wiring up an amplifier, or air pump, or big offroad lights in a car... Those are all around 20A also and equal potential for burning something to the ground if you do it wrong.

Just be smart, read up on it, do it right.

Think what I'll do is do all the work outside the box working backward and bring in an electrician to inspect that work and do the actual box hookup and ask him to teach me how do do it while he does it. Like I said earlier, I've got no death wish.

In reply to SVreX:

With the main breaker off, the only thing hot in the box are the two lugs for the main feeder or whatever it's called, which carry the full capacity of the transformer on the pole. Dangerous yes, but use extra caution when working at the top of the box hooking up the neutral and ground wire to the terminal block and you're fine.

I am a pro. I think one of the worst things is someone who thinks they know what they are doing. I can't believe some of the things I have come across that were done by a homeowner/handyman. I have always told people that home wiring is very simple stuff and the picture book sold at the box stores are great. If you a little unsure of yourself get someone qualified (and insured to cover your butt).

Kenny_McCormic wrote: In reply to SVreX: With the main breaker off, the only thing hot in the box are the two lugs for the main feeder or whatever it's called, which carry the full capacity of the transformer on the pole. Dangerous yes, but use extra caution when working at the top of the box hooking up the neutral and ground wire to the terminal block and you're fine.

Right.

Like I said, the panel box is hot.

And 99 times out of 100 you will be pulling the new wire into the top of the box, right next to the hot lugs (full amperage of the service), so be careful.

In reply to SVreX:

True, I'm used to helping people out with overstuffed boxes where going in from the top isn't often a good option.

In reply to SVreX:

This will be my exact situation so there ya go.

I'm not sure how much electrical regulations vary across the US, but in my province in Canada it's illegal for you to do any electrical unless you are a licensed electrician (or have it checked/signed off by one). Everything more complex than changing a bulb needs a permit (which can only be issued to an electrician, but a licensed electrician doesn't actually need a permit for basic stuff).

I didn't have a huge issue with that until I got screwed and charged $350 to install 2 outlets on a new circuit, in the same unfinished room as the panel. One was 6' from the box. berkeleyers.

Oh, and despite me asking repeatedly for 20A, he gave me 2 separate 15A circuits. Cause that's just as good. grr.

US code is pretty universal- homeowners can do their own work on their personal residence. Permits and inspections vary by community.

One major exception is mobile homes.

SVreX wrote: US code is pretty universal- homeowners can do their own work on their personal residence. Permits and inspections vary by community. One major exception is mobile homes.

On the one hand, that sounds much nicer. On the other, I've seen the hacks the previous owner did to our house. For example, sump pump powered by a tiny (18 or 20g?) extension cord plugged into one of those sockets that screw into a light socket. So drawing 12A (verified by electrician, more at start) through a 250w rated light fixture. With the ground prong broken off, of course. When I removed it, the extension cord was charred for most of it's length. Of course, the home inspector also thought it was fine.

It's like safety inspections on cars. Sure it's a pain, but I'm really glad the car next to me has had one.

In reply to bigev007:

That's not electrical work. That's making a bad decision when plugging in an appliance.

Same thing could have happened with a vacuum cleaner.

Are you suggesting we should have laws and inspections to insure homeowners plug stuff in the right way??

Yikes.

In reply to bigev007:

There's a difference between a "home inspector" (free-lance; hired by home buyers) and an "electrical inspector" (employed by local township).

While I'd like to think home inspector training would include some basic electrical code information, I wouldn't expect it. A lot of if comes down to liability.

When I did the wiring for the ex's house reno/addition, the rough-in wiring was inspected by the township electrical inspector, but oddly enough he didn't go into the basement to look at the main panel. Of course, we were somwhat thankful for that as there is a TON of non-compliant wiring in the basement installed before she bought the house, although everything I installed was to code.

SVreX wrote: In reply to bigev007: That's not electrical work. That's making a bad decision when plugging in an appliance. Same thing could have happened with a vacuum cleaner. Are you suggesting we should have laws and inspections to insure homeowners plug stuff in the right way?? Yikes.

I know that's a bad example of actual electrical work. I guess it's just a good example of his bad judgement and the way he did things. There's a lot of hidden splices/pigtails, stuff not connected well, hacked and cut things. Like a junction box behind a kitchen drawer (under counter) with no cover and loose live wires. That would have been fun if I overstuffed the drawer. I think all fixed now, though.

It's not the electrical inspector's job to insure the entire house is up to code.

It is only his job to inspect the currently permitted work for code compliance.

In your case, the addition/ renovation work, NOT the panel.