110v line to 220v line?

[Ralph Mowery]

If the neutral is the same size as the hot wire it is impossiable to overheat it unless you are overheating one of the hot wires in normal operation.

[Doug Miller]

Not if they're connected properly.

[Joseph Meehan]

Well that is true if they are properly wired to opposite phases, but from what we have seen of the OP I fear it is a 50:50 chance of him getting it right.

I think Storm has it right.

[Joseph Meehan]

But is the OP who appears to not give much credit to code, even know there is more than one way they may be connected?

[Stormin Mormon]

Well, supposing I'm running a space heater (15 amps) on the black wire and the bare wire. And running a hair dryer (14 amps) on the white wire and the bare wire. That's 29amps in a bare piece of 12 ga.

How would you wire it differently?

[Joseph Meehan]

If the space heater is on one phase and the hair dryer is on the other phase that neutral (bare or otherwise) is carrying one amp. Of course that means it is live and can produce injury and can be shorted out to ground. Which is why you can use the same size wire and why it should never be treated as a ground wire.

[Doug Miller]

Google on "Edison circuit".

[Oscar_Lives]

Sounds like Stormy fell asleep in Basic Electricity 101 or even junior high Science class...

[Steve Scott]

Actually he's right on this one. This fails code on two points.

You can't have a ground act as a current carrying wire.

You can't run two circuits off >

[gfretwell]

Go look at your wires coiming into the house. Your whole house runs on one neutral and it is smaller than either phase..

If he drove a ground rod at the second building connected to the grounded conductor and installed a 2 pole disconnect the real issue would boil down to the bare neutral.

It's wrong but it is far from the most dangerous thing in the world.

[Mark Lloyd]

That's 1A in the neutral if they're on opposite phases. However, how are you going to make sure noone ever moves a breaker wrong, butting them on the same phase and making it 29A?

[Tom Horne, Electrician]

Steve Scott wrote: > Actually he's right on this one. This fails code on two points. >

Article 100 Definitions. Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.

It is a little like running one twelve volt bulb and two six volt bulbs from two six volt batteries connected in series. I can ground the common point of the two batteries to make the example even more representative. If I want to run a six volt load I connect it across only one battery by applying it between the outer end and common point of either battery. If I want to run a twelve volt load I connect it to the outer ends of both batteries. For this arrangement to work the batteries must be connected in series with one batteries negative connected to the other batteries positive. If the two batteries are connected with both positive poles or both negative poles together than the voltage across the non common ends of the two batteries is zero.

The original Edison circuits had DC on them but instead of batteries they had two DC generators running in series with their common point grounded. Originally used to reduce voltage drop in distribution Edison circuits continue to be used today as a labor and materials conservation technique. DC batteries arranged in Edison arrays are still used to supply single phase emergency lighting panels in older buildings. When the power fails the contactor supplying AC 208/120 single phase power to those panels drops out and connects the three conductors of the single phase feeder to 120 two volt wet cells connected in series and grounded at the common point between batteries sixty and sixty one. That leaves

120 volts between each ungrounded conductor and the neutral and 240 volts between the two ungrounded conductors.

[Tom Horne, Electrician]

Any feeder or branch circuit that supplies loads that are connected to two or three ungrounded conductors must be protected by common trip breakers or breakers equipped with listed handle ties. To disarrange the circuit you would have to move at least one of the conductors to a different breaker rather than just moving the breaker and that isn't very likely.

[Joseph Meehan]

This is another example of what can happen when you want to ignore a code requirement because you don't understand. If it is code, you follow it. End of discussion.

[Joseph Meehan]

It is dangerous I fear you also subscribe to the idea that if you don't understand they they wrote the code that way, you can ignore it.

[Steve Scott]

Go look at the NEC. You can certainly wire your home any way you choose.

BTW, are you a licensed electrician or a HO?

[Mark Lloyd]

I guess you figured out that last word was supposed to be "putting". Spelling checkers can do bad stuff like that.

That's what I wanted to know. I have a shared neutral circuit in my house that's working OK now (different phases). I need to fix the breakers.

[WConner]

" This is enough to indicate you should not be attempting this work. Your plan does not meet code. "

Thought I posted a reply to this but have been gone a couple of days and don't see it here.

Anyway, I did pose the question and perhaps you should read my last reply which you posted in your message. Pardon me but I think you may have a somewhat swelled head. I have completely wired 3 new houses, one a story and half with basement and rewired 3 older homes, one a story and half brick with plastered walls and basement. All have passed inspection without problem. Now if you would like to challenge this, one of us could stand to make a lot of money. I am glad to see there are a few people who took a sensible view of the question, thanks to you guys.

There are many knob and tube wired houses still in existance with entire floors running off one circuit. One of my re-wire jobs was one of these. Point is, code is over kill in some instances even if one must follow it.

Walt Conner

[Joseph Meehan]

I am glad you agree that we much follow it. However it is my experience that those who believe it to be overkill just don't understand why it was written the way it is.

[Doug Miller]

Of course, you may wind up burning it down, too....