Large Scale Central

120V AC questions

I upgraded my entire house when I did my new addition. It had no GFCI circuits and no Arc Fault circuits. I used GFCI outlets in the old bathroom and the sink side of my kitchen. The fans in both bathrooms where upgraded with GFCI breakers and the new jetted tub has GFCI breakers. My bedrooms (2 circuits) now have Arc-Fault protection. I just installed a GFCI breaker on my only outdoor outlet that I thought was on a GFCI circuit but turned out it was on a different circuit.

David Maynard said:

Todd when my pond pump split it case, I handled the pump underwater with no issues. Its when I lifted it clear of the water, I became the electricity’s path to ground, and… Lets just say it wasn’t one my most pleasurable experiences.

Had I known the pump had split its case, I would never have handled it with power applied. I thought it was just clogged.

I shocked the tar out of myself with a split aquarium pump, it did kinda tickle me in the water, but didn’t put two and two together and lifted it out and it jumped up and bit the %()^* out of me.

Devon and Michael, the idea of putting multiple circuits on the same neutral could cause a real problem unless both/all feed off the same breaker. If two circuits share a neutral but are fed by different breakers on the same phase, the neutral would have the sum of the currents on it, and that wire is not protected by a fuse or breaker. If two circuits share a neutral and are fed by separate breakers on different phases, the neutral will only carry the difference in amps of the amps on the circuits. But it’s against code, I’m pretty sure because if someone starts moving things around in the panel, the circuits could end up on the same phase.

I am basing this post on my limited knowledge of electrical circuits, so if I have this wrong I would appreciate being corrected.

Normally getting shocked by 120 volts is not fatal, BUT IT CAN BE IF YOU ARE WELL GROUNDED standing on concrete or wet ground.

Yes, to all the above, and for outdoor, I find that GFCI breakers last longer than a GFCI outlet, even in a covered outlet box.

I have a lot of outdoor lighting and outlets, I speak from experience and I am in a nice dry location in San Diego. We don’t get humidity or lots of rain.

My original guys installed GFCI outlets outside, and they all went bad eventually, a single GFCI breaker in the panel lasts longer and is less wiring hassle.

Greg

Greg,

Is that a GFI breaker in each circuit or one in the box?

I’m replacing them about one a year at Sis’s place.

PS: There’s one that I couldn’t find the breaker for it. Got all tingly as I changed it out sitting on the ground. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)

Thanks,

John

Greg Elmassian said:

Yes, to all the above, and for outdoor, I find that GFCI breakers last longer than a GFCI outlet, even in a covered outlet box.

I have a lot of outdoor lighting and outlets, I speak from experience and I am in a nice dry location in San Diego. We don’t get humidity or lots of rain.

My original guys installed GFCI outlets outside, and they all went bad eventually, a single GFCI breaker in the panel lasts longer and is less wiring hassle.

Greg

I agree with the GFCI breakers especially on a dedicated outdoor circuit. I know that your “supposed” to be able to wire the first outlet with a GFCI outlet and that does protect the entire circuit but outdoors it just seems like a better idea to go with the breaker. The electrical inspector that inspected my addition actually talked me into using outlets at the first point in a circuit as opposed to breakers in order to save space in the panel. I could use slim breakers instead of full size breakers. The only places he recommended GFCI breakers was on circuits with no outlets which in my house was the bathroom fans which required GFCI protection.

But I have all the space I need in the garage sub panel and since everything will be in a potentially wet environment it seems a breaker is a better idea.

John Caughey said:

Greg,

Is that a GFI breaker in each circuit or one in the box?

I’m replacing them about one a year at Sis’s place.

Thanks,

John

Each circuit would require one in the panel. So if you have five circuits coming into the panel that need GFCI protection you would have to have five GFCI breakers. Make sure you wire them correctly. The GFCI breaker will have its own white neutral wire The neutral returning from the circuit will need to be wired into the breaker and then the neutral attached to the breaker is then connected to the bus bar. If you don’t wire the neutral into the breaker then it wont operate correctly, I don’t know if it doesn’t work at all or if it just makes it a normal non-GFCI breaker, but I know it needs to be wired right in order to work.

Just FYI entire circuits can be protected with a single outlet provided the GFCI outlet is the first outlet in the series. Everything beyond the first GFCI becomes GFCI protected. This is how the electrical inspector had me wire my bathrooms and kitchen (sink side) in order to save space in my panel. However, for my piece of mind and as Greg says for them wearing out I like breakers. I have a mix of both.

Oh and one last thought and this might be obvious but I watched a friend do it, if you have a GFCI breaker the outlets do not have to be GFCI. He spent a great deal of money putting a GFCI outlets in every outlet in his yard and he had a GFCI breaker. One at the beginning of the circuit, whether breaker or first outlet is all you need.

Yes, 2 GFCIs in a circuit will tend to fight with each other.

Devon, since the GFCI is looking for a difference in current between the hot and neutral, I would suspect if its not wired like you said, it would constantly trip. But that is a suspicion on my part.

As for sharing neutrals, that sounds really dangerous. Since current is the same in all parts of a series circuit (Kirchhoff’s current law), then all current on the hot wires would also be on the neutral wire. As for “out of phase” hots sharing a neutral, that still makes me twitch funny, because there are times when the 2 phases aren’t completely out of phase with each other, and for that spit second, the neutral would be carrying more then its rated for.

Well until Michael suggested the single neutral I wouldn’t have even guessed to do that. All my wiring experience is with internal house wiring using romex. So you always have a hot/neutral/ground that returns to the panel.

Now here is another reason I can think to run a neutral with each circuit. Since they will be GFCI breakers for each circuit and each GFCI needs a neutral fed to it to monitor current drop, it wouldn’t work properly without individual feeds. The returning neutral has to be fed back to the breaker and I would think it couldn’t share it otherwise it might not get the right current fed to it. especially if its get twice the current. So I can’t see at all how a single neutral would work in a GFCI circuit.

So I will run 5 conductors for two circuits. Maybe 7 we will see. The third circuit would be completely future in nature. I really can’t see why I would need 3-20A circuits to my back yard, that a lot of power. But just as soon as I say that and only install two I will surely want three. Now on the issue of color coding, with romex this isn’t an issue because they are bundled already. What ,if any, standard exists for color coding single conductors in conduits. I mean I am used to black white and bare copper. One circuit could be black and white and then green to replace the bare ground but what should the second and third circuit be colored. Phone wire is paired and I am wondering if the same methodology applies or what. You wouldn’t want all the neutrals to be white because then you could not distinguish which neutral when to which circuit. So is there some standard pairing?

Seems to me in reading that the hot should always be black and the neutral should always be white. Which would make sense and eliminate confusion. I have also seen commercial panels done where this is the case and then they wires are color coded using electrical tape to denote the pairs. For example one set would be a black wire and white wire with a piece of say yellow tape on each to denote the pairing. This would seem to make sense. I mean you have to keep them paired somehow especially with GFCI.

OK well absolutely everything I have red is that only white and grey are used for neutrals and green or bare wire is always a ground. Black and red are typical hots but it can be any color other than grey white and green. So with that said it would seem prudent if using all white neutrals to color code them with the individual hots. Using red for a hot i could see as being confusing because it could be mistaken for a 240 run or a second conductor in a multi-switch arrangement.

Seems that The KISS system is prudent. Running different color hots and then color code the whites at junctions to denote which neutral is for which circuit seems easiest.

Devon, if you do color code your pairs make sure you keep the color coding on the wires after you make them up at the outlets, junction boxes or panels. That way at a future date when you add or change things in the panels or boxes you will know what you did before. Also keep in mind that electricity is color blind. I have seen licensed electricians use the white wire for the traveler in a 3 way switch application. I have a “wigi” that I use to test if a wire is hot or not as well as a voltage tester made by Klein Tools (NCVT-1) that I hold next to a wire and it will tell me if it is hot or not. They sell them at HomeDepot and Lowes.

Thanks for the long reply. You lost me at doing any wiring in those boxes. If I could have pulled a normal breaker and replaced it with a GFCI breaker I would. Beyond that the liability for me, is too great.

John

Devon,

My previous thoughts and comments were in concert with what I typically work with; three phase power distribution within warehouses/buildings, should have changed hats for residential needs. That said three branch circuits one line each of phase L1-L2-L3 and a single neutral are accepted practice. I believe same is true of single phase systems one line each for a branch circuits sourcing L1-L2 and a single neutral is okay too. In any event a single line/phase per neutral is best practice and in todays world of computers and other various equipments requiring “clean” power it makes sense. The “NEC” allows for the practice of shared neutrals, I also believe local interpretation (which trumps NEC) may or may not allow shared or common neutrals too. Luckily Bill noted my shared neutral comment was not akin to your needs; thanks Bill!

Were presently completing the installation of a main distribution panel in Stockton, CA rated @ 2000A 480Y/277V, 60 hertz, 4-wire, 3 phase system in a facility were presently retrofitting for an industrial laundry garment cleaning plant, in this circumstance the main 2000A panel enclosure is located outside the building and feeds multiple sub-panels and two 800A distribution panels feeding additional sub-panels inside together with dry transformers stepping down 480V to 120/208V lots of considerations herein.

USA color codes;

208-240VAC L1/black-L2/red-L3/blue line voltage, white/neutral and green/ground.

208-240VAC Single phase systems are typical of residential environments in the USA, these are comprised of two lines; L1/black and L2/red, neutral/white and green/ground. For a three phase system you’d simply add the third line or L3/blue.

We always identify the feeders or lines and neutral coming in from the utility landing in the panels/sub-panels with the correct colors as noted above. It would also be typical to see black and red wires used for branch circuits in a single phase system such as yours.

440-480VAC: L1/brown-L2/orange-L3/yellow line voltage, grey/neutral and green/ground. These voltages are common in commercial and industrial environments.

Michael

Well Michael now that you established the common neutral in industrial three phase thatakes total sense. I am no expert but I work for a public water utility and like to “help” professionals when we hire them. It’s a great way to learn. Anyway I have “helped” electricians wire soft starts and line shaft motors and even a couple of 80kw gensets. And I distinctly remember four wires. Three hots and a common neutral.

Belated reply to John:

Yes, GFI breaker for each circuit. I have about 8 outdoor circuits, and each circuit had 2 to 4 outlets. The first guy that wired it made a mess, the first outlet had a GFCI and then the load side went to the next outlet which also had a GFCI…

When these stupid things fail they can fail all sorts of ways… it’s hell to debug.

Changed them all back to standard outlets, and put GFCI breakers on all the circuits. Funny thing one breaker kept tripping. I figured out that one conduit that had 2 circuits had the neutrals mixed up. Under normal breakers this was not detected, but the GFCI breakers were having none of it.

Much better now, and no more problems with GFCI outlets outside going bad from moisture every year or so, the dang things ar $20 each.

Greg

John Caughey said:

Thanks for the long reply. You lost me at doing any wiring in those boxes. If I could have pulled a normal breaker and replaced it with a GFCI breaker I would. Beyond that the liability for me, is too great.

John

John,

I took a very long winded way to say yes it as simple as replacing a breaker. . .kinda. To replace a normal breaker you kill the main, yes I kill the main, and you unscrew the pole holding the black wire pop the breaker out and pop a new one in and reconnect the wire. To replace a regular breaker with a GFCI you kill the power disconnect the black wire and pop out the breaker just like a regular breaker. There is an added step. You also find te white neutral that is paired with that black wire. And disconnect it from the bus bar. Now the new GFCI breaker will have a white wire attached to it. Pop the breaker in and connect it’s white wire to the bus bar in the same location as the circuits white wire that you disconnected. Then following the directions install the circuits white wire to the breaker where it belongs and the black wire where it belongs. Its that easy. It’s really pretty simple.

To minimize cost and have the most power available I would run a 14 or 12 guage 220 volt wires.

So there would be a green ground, white neutral and a black plus red wire for the split phases. The load on the white wire could be minimal at times as the current flows in opposite directions on the white wire thus canceling each other out.

Never, never omit the green ground wire, and for lightning protection on swimming pools it should be #8 here in Massachusetts and I would do the same for a long run from the house.

Dan Pierce said:

To minimize cost and have the most power available I would run a 14 or 12 guage 220 volt wires.

So there would be a green ground, white neutral and a black plus red wire for the split phases. The load on the white wire could be minimal at times as the current flows in opposite directions on the white wire thus canceling each other out.

Never, never omit the green ground wire, and for lightning protection on swimming pools it should be #8 here in Massachusetts and I would do the same for a long run from the house.

Dan,

No I would never omit the green ground wire ever. I know what its for and why it is important. My issue was never should I omit it. My question only was does it need to return to the panel or could it be run to another grounding source closer to the point of use. The thinking WAS that when the wire is returned to the panel it is attached to a bus bar that in turn is attached to a big metal rod in the ground. Therefore I figured I could introduce an additional path to the ground with big metal rods closer to the source and not have to run 150ft of ground wire to have it just go into the ground anyway. Thanks to the advice here I understand now why it is a good idea to return it all the way to the panel. It was never to omit a path to ground.

Now I do need you to explain your thinking on why I should run 220V to my back yard. Your talking a 240V breaker in the sub panel in the garage, four wires, and then a sub panel with breakers and then the individual circuit runs. If I run two individual circuits I am talking two breakers in the garage sub panel and five wires; no additional breakers and no sub-sub panel.

Now if you are talking an all new sub off the main panel to a dedicated sub panel for the back yard that would require a serious amount of work. getting wires into my main panel would require me to tear out a cabinet and sheet rock. That is not worth while for two circuits that quite frankly wont be running all that much off of them. I will be getting more than ample power from my garage panel. it may only be a 60A sub but there is very little running off of it at any given time.

3 wires plus ground to 2 duplex outlets in one fixture would give you 4 places to plug in power without a sub panel.

Each duplex outlet can be the GFCI and be local to the user, not back at the main panel.

Each duplex can have 15 amps (14guage) or 20 amps (12 guage).

Less wire is lower cost, and just a standard 220/240 breaker at the main panel.

PS:

I have pulled permits and done all my own wiring as my town allowed this and I passed inspection on all my wiring.

Biggest thing is to follow the code, some places do not allow home owners to do their own work.