4800 watt construction heater wiring

[DG]

You don't need a neutral to utilize the 220, in fact doing so negates it from _being_ 220v. This is 180 degree out of phase AC, not DC. All you need is a voltage potential and somewhere for it to travel, for current to flow. This is provided by the two 120v out-of-phase legs of your typical residential service. Hopefully you do not become part of the conduction path, and is the primary reason that most woodworking equipment requires a ground. It is not designed to be a current carrying conductor.

Great confusion exists among novices as concerns Grounds and Neutrals, especially when it involves outbuildings. Protection against electrocution and lightning are two of the main reasons that the current grounding guidelines/codes exist.

The ground on most 220vac equipment is for safety grounding only. It is a ground, not a neutral, although they do eventually connect together in your main panel, but never in an in-house subpanel.

Older stoves and cloths dryers sometimes used a common ground/neutral to provide 120v for lamps and timer motors, but the new code and all new appliances require a 4 conductor plug and wiring. Two hots, a neutral, and a ground. It's a safety thing...

Get a copy of the NEC if you want to read up on how to wire things safely, and to code. Otherwise, please, call an electrician. Mistakes can be deadly and cause great property loss.

FWIW

[DG]

More precisely, should have read:

...all new 220v appliances that need the use of 120vac for lamps/motors/etc. require a 4 conductor plug and wiring...

FWIW

[Doug Miller]

There isn't a "return path" per se in a 240V circuit. In a 120V circuit, the hot is at a potential of 120V with respect to ground and neutral. In a 240V circuit, the potential between the two hots is 240V; each is at a potential of

120V with respect to ground and neutral.

That's to ensure that the neutral is at true earth ground potential.

That's not why you popped the breaker. Not having seen what you did, I can't say why you *did* pop the breaker, but I can say with certainty that tying neutral to ground didn't trip the breaker, in and of itself. Unless it was a GFCI breaker.

Means you had it connected to a hot lead somewhere...

Yep, it's basically the same concept.

Residential electrical supply isn't quite the same animal. There are a number of books available at any decent library or bookstore, or at most home centers, if you want to learn more.

[R. Pierce Butler]

Troy wrote in news:eh292s$72a$ [e-mail]:

Troy,

There are two 110 volt circuits in most CB boxes. Each is independent. They also happen to be 180 degrees out of phase with one another. The upshot is that while each is 120 volt with respect to ground, they are 220 volts with respect to each other. The neutral is there for a variety of reasons but not necessary for operation at 220vac. Ever wonder how your electric clothes dryer works? The main coils are wired for 220 but the light bulb and other parts like the timer use one side and the neutral.

[j.valente]

Thanks!

With the groups help I was able to figure out what I was doing wrong.

As suggested I tested the main lugs in the subpanel I got 220v, but did not get 220v when I tested the outlet accross both hots.

Turns out the the sub-panel installed only has two positions that will give you 220v. I didn't connect the breaker to either one of these. I removed the breaker, and re-connected it to the correct lugs and got

220v accross both hots. The heater now works! The inside of the panel door has a diagram that shows which lugs are 120v and which are 220v.

Thanks for all your help!

[Troy]

Wait, I thought we just got through learning there IS no neutral in a

240 circuit?? I didn't realize that they were out of phase with each other.

Troy

[Troy]

its been forever since I read any of the electrical code stuff and OBVIOUSLY don't use it very often hardly. I'll be sure to ask any questions before I mess with anything other then 120. At least I know what I'm doing with that.

Troy

DGG wrote:

[Troy]

OK! now this makes sense.. I can center-tapping transformers sometimes in multiple places as a youngster to get different voltages for power supply's and ham radio circuits.

Troy

Scott Lurndal wrote:

[Mike Marlow]

No - the discussion was that for a 220V circuit, no neutral is needed. However - when looking to also utilized 120V within a device that is hooked up to a 220v circuit, then a neutral must be provided. The example given was a clothes dryer. The dryer coils run on 220 and your clothes would dry just fine with no neutral. However, the timer, any lights that may come on when you open the door, etc. run on 110V. Therefore, you have to supply a neutral so that those 110V devices can operate off of one leg of the 220V, and neutral.

[J. Clarke]

There is no neutral in a 240 volt circuit. Going from either leg of a 240 volt circuit to neutral gives you a 120 volt circuit.

Some appliances require both 120 and 240--they need a three-wire circuit (two hots and a neutral) plus ground.

[Tex]

I've followed this thread and read some good questions and posts. However, something of a trivial nature I guess, is the reference by some to 110/220 VAC and others to 120/240 VAC. I grew up nearly always hearing 110/220 until I worked several summers in college for an electrical contractor. There, I found it was almost always really

120/240. Throughout my career, managing projects involving building computer facilities and working around electricity, I've found the same thing -- 120/240. I'm curious where the 110/220 terms/measurements came from. Was that, at one time, the norm.

Tex

[Doug Miller]

Yes. It's gradually increased over time. 110, 115, 117, 120 -- some appliances are marked 125 now.

[Scott Lurndal]

Actually, the 240 in 99% of US residential settings is single-phase, using a center-tap to derive 120v. HV Distribution circuits are three phase, with the phases 120 degrees apart. One of those phases feeds the distribution transformer serving your residence, wherein there is a center-tap which provides the neutral to the service entrance.

scott

[CW]

It's AC, think about it. If you "know electronics" it should become obvious.