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| Subject - Two Pole Breakers | |
| manoakes | You are running a 12/3 circuit - you are using black and red as a 20 amp 110 circuit. Why do you have to put this on a two pole breaker in St Tammany Parish,LA instead of putting it on a two single pole 20 amp breakers? |
| Romex Racer | Well, what you describe dosen't make sense. Sometimes local jurisdictions come up with their own codes, they sometimes feel that they're smarter than the NFPA but all they really achieve is higher installation costs that get passed on to the hapless citizens of the community. I'd ask the inspector why this is the case. When I meet a new inspector I have a question I always ask, I call it an IQ test, I use it to deduce the inspectors level of understanding. Most fail. I don't get paid till the job passes inspection, if it's a minor ego thing that the inspector wants that's not a part of the NEC, I don't argue, I just say "yes sir!" and do what he wants. I just wanna get paid. This might be such a case. Sometimes the inspector is delibrately holding up the job because he wants a bribe, this is common in Glendale, California. When I sense this is happening I ask "is there something I should be doing that I'm not? Do I need to hire a consultant? Can you advise me who I need to contact to help me complete this project?". If there's corruption, he'll refer you to an engineer or a draftsman. Once in Los Angeles a inspector said the only source for tinned copper was his brother in law, so I bought some and everyone was happy... When something doesn't make sense, it's either a misunderstanding, a local nonsensical code (I've seen plenty) or an inspector with an agenda. I'd just slap a 2 pole breaker in there and move on... .............RR I doubt your boss is trying to hide anything. But you can always ask the inspector, |
| Viper | You must be talking about multiple circuits, correct?? or do you mean one circuit? |
| manoakes | quote:no, I am talking about two single circuits in residential wiring |
| Romex Racer | If the 2 circuits terminate on the same device you must use a 2 pole breaker. A common practice is to break the jumper tab on a duplex recepticle and put one circuit on the top for a dishwasher and the other circuit on the bottom for the disposal. If you didn't have a 2 pole breaker, you might turn off the disposal circuit but the device is still live as a result of the other circuit, you would grab the device and get a shock... |
| manoakes | quote:why do they have to be put on a 2 pole breaker - logic is 2 single pole breakers - ie: one circuit for living room - one circuit for dining room - not understanding the logic of why they can't be put on 2 single pole breakers vs a 2 pole breaker - this is supposed to be a code violation in St. Tamany Parish, LA by putting them on single pole breaker-is this because the contractor I am working for is trying to hide the fact that this is supposed to be a single circuit instead of a 220 circuit? |
| Viper | I'm alittle lost here but, here's my take. You can use two separate single pole breakers(on different legs)without tie, as long as the circuits(red and black) don't end on the same yoke. So in your case you said living room and dining room separate circuits, that would be fine. All netural wires need to be pig-tailed. |
| blackrd | What we are talking about, defined in the NEC, is multi-wire branch circuits. Typically, in some areas, the use of handle tyes or two pole breakers hasnt been required, in some areas this has been a requirment. On multi wire circuits, your installation should prevent the opening of your nuetral or grounded conductor,( did it one time, couldnt fathom why the lights were brighter and the bathroom fan ran faster) although I think this is a requirment of multu-wire branch circuits. I believe, but am not sure, that the 2005 NEC is requiring 2 pole breakers(or handle ties on single pole breakers)on multi-wire branch circuits. I am waiting for the 05 as a birthday present so havent bought one yet. I may be wrong about that provision in 05 NEC, if so I can stand to be corrected. |
| Ryan_J | The only time a handle tie is required in the 2005 is for multiwire branch circuits that terminate on the same yoke of a device. The 2002 only required this for dwellings, the 2005 requires it regardless of occupancy type. |
| blackrd | Ryan, isnt there a provision for not opening the nuetral, I.E. to change out a receptacle you not making an opening in your grounded conductor also? |
| luckyshadow | I do believe you are still required to pigtail the grounded conductor on multiwire circuits. I pigtail them all myself , this way if one device goes bad that is the only device with out power.Makes service calls nicer. |
| Ryan_J | Yes, 300.13. Also, the 2005 adds a FPN to 210.4 telling the user to see 300.13 for this reason. |
| blackrd | 300-13(b) DEVICE REMOVAL;In multi-wire branch circuits, the continuity of a grounded conductor shall not depend on device connections such as lampholders, receptacles, etc., where the removal of such devices would interrupt the continuity. I really need to brush up on my NEC, I shouldve known this. |
| Ryan_J | quote: You did know this, you just didn't know the reference off the top of your head. It looks like you're doing just fine to me 
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| blackrd | Thank you |
| PEI | Note where Viper said, 'on different legs', a 2-pole breaker forces this to happen. Never really thought about it, but what happens to the neutral current in a 240V single phase system when you are "sharing the neutral" ...? |
| Ryan_J | Nuetral current in a single phase is the equal to the difference between the two legs current. |
| PEI | DEFINITELY AGREE, AND IT MAKES SINCE THAT IT WOULD SINCE IT IS THE CENTER TAP. IT'S JUST THAT I CAME UP THROUGH THE INDUSTRIAL END OF THIS BUSINESS AND I DON'T DO RESIDENTIAL (BACKWARDS OF EVERYONE ELSE). |