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Chief09
Aug 10, 2010, 04:18 PM
I have a electric stove top grill that requires 240VAC. 4 wires, red, black, white and green. I also have a step up transformer that converts 120VAC to 240VAC. How do I wire the stove top grill to a three prong outlet in the converter?

smoothy
Aug 10, 2010, 04:38 PM
You do realize you apprear to be describing a grill that takes 240VAC split phase (those colors are used for that in the USA, two Phases of hot, neutral and ground)... and you are talking about a single phase transformer which are two totally different and incompatible things.

stanfortyman
Aug 10, 2010, 04:38 PM
What is the draw of the grill?

What is the capacity of the transformer?
What is the make and model of the transformer?

Are you referring to a regular 120v receptacle? If so they are only 15 or 20 amp circuits.

stanfortyman
Aug 10, 2010, 04:39 PM
You do realize you apprear to be describing a grill that takes 240VAC split phase (those colors are used for that in the USA)....and you are talking about a single phase transformer which are two totally different and incompatible things.
Can you explain the difference, because you lost me on this one.

smoothy
Aug 10, 2010, 04:47 PM
Can you explain the difference, because you lost me on this one.

I meant to say a nominal 220VAC grill. I have spent years in Europe and 220V devices there ALL use 3 never 4 wires, many are just 2, and ALL there are single phase.

220VAC in the USA is split phase... not single phase. Two 120vac hots that are 180 degrees out of phase with each other(one is high when the other is low and vice-versa). Third is a neutal or Common and the fourth is ground.

Being they mentioned 120VAC it's a given they are in the USA or Canada, most everywhere else 220v single phase is what is nominal. You can't convert single phase power to split phase with any transformer I've ever seen.

stanfortyman
Aug 10, 2010, 05:19 PM
220VAC in the USA is split phase...not single phase. Two 120vac hots that are 180 degrees out of phase with each other(one is high when the other is low and vice-versa). Third is a neutal or Common and the fourth is ground.

In the US split-phase is single phase. Nobody really uses the term split-phase.
Not all 240v loads require a neutral. In fact, if a 240v load requires a neutral it is a 120/240v load, not a 240v.

A 240v single phase 3-wire circuit is extremely common.

Straight 240v AC power is 240v AC, regardless if it is single phase or split phase.
What am I missing here? :confused:


***Edit, I just re-read your replies and I think I get what you are saying now. You are only calling it split-phase because the grill IS a 120/240v 4-wire circuit.

stanfortyman
Aug 10, 2010, 05:21 PM
Bottom line is the OP cannot use a 240v converter/transformer for a 120/240v load.
I am not sure why a 240v grill would need a neutral any way. :confused:

smoothy
Aug 10, 2010, 05:33 PM
In the US split-phase is single phase. Nobody really uses the term split-phase.
Not all 240v loads require a neutral. In fact, if a 240v load requires a neutral it is a 120/240v load, not a 240v.

A 240v single phase 3-wire circuit is extremely common.

Straight 240v AC power is 240v AC, regardless if it is single phase or split phase.
What am I missing here? :confused:


***Edit, I just re-read your replies and I think I get what you are saying now. You are only calling it split-phase because the grill IS a 120/240v 4-wire circuit.

240V single phase is common OUTSIDE the USA. You won't find it in any house in the USA. Residential power is split phase... its NOT two paralleled 120vac circuits... that only nets you 120vac. There actually IS a 180 degree phase difference. How else could you achieve 209vac single phase buy using the two hots as a hot and return if they weren't out of phase (no that's not very commonly done in a house). I've done a lot of house wiring over the years and have yet to see a 240VAC potiential between a hot and ground.

Now this is all different from three phase comercial power which you don't find in residences.

Forget if you might see that in a 480vac 3-phase commercial power,its been a long, long time since I was even allowed to touch that, and never did it much then (actually that was a 540vac 3-phase 50 hz I dealt with overseas feeding large UPS systems). Current job prohibits it expresively by job description. Heck, under current OSHA rules I can't even touch a main breaker at work, but then there are very good reasons for that.


I'm sure you are just misreading what I have wrote for whatever reason (could just be how I wrote it). I'm certain you know what I'm talking about.

No I'm not a electrician... I am a degreed electronic Engineer that has enough cross discipline knowledge to do most of my own work.

donf
Aug 11, 2010, 06:41 AM
Smoothy,

You are an "Electronic" engineer. The vernacular used by "Electrical" field is slightly different than that used in the electronic world.

The term “Split Phase” while accurate is not used, “Single Phase” is the term used.

Sorry, but that is the term used and is the accepted description. Please refer to the NEC 2008 code book for verification.

smoothy
Aug 11, 2010, 06:59 AM
Smoothy,

You are an "Electronic" engineer. The vernacular used by "Electrical" field is slightly different than that used in the electronic world.

The term “Split Phase” while accurate is not used, “Single Phase” is the term used.

Sorry, but that is the term used and is the accepted description. Please refer to the NEC 2008 code book for verification.I have that at home and can look it up tonight out of curiousity, but I'll take your word for it on the terminology, I do know electricians have to know a good portion of that code by memory as part of getting their License. I have read it and do reffer to it from time to time but do not have it memorized.

But from my fields perspective it seems odd they would do that however as it would imply that the two hot feeders are in phase sync... when in reality they oppose each other at any given moment. Simply proven with a dual Trace oscilloscope syncing and triggering off one of the pair which would show the sine waves of the AC power being opposites at any given point of the wave. DVM would idicate it as well.

Of course electricians all know this... its just that the accepted terminology in the field would indicate otherwise to someone who knows little about it (as in someone with no or little Elecrtical or Electronics training).

tkrussell
Aug 11, 2010, 07:15 AM
The term "Spilt Phase" simply means that a single phase transformer has a center tap, typically, a 240 volt transfomer with a center tap to provide two 120 volt legs.

It is still single phase.

In the trade, we simply call it a 120/240 volt system.

Historically it was called an Edison Three Wire System.

Chief got the answer from Stan, the grill that has a 4 wire feeder should require a 120/240 volt service with equipment ground, and that cannot be powered by a 240 volt source.

The grill probably needs a neutral for 120 volt pilot lights, control, perhaps a built in fan.

Who knows, until Chief gets back with answers to the questions put forth to him.

donf
Aug 11, 2010, 07:23 AM
Smoothy,

Electricians are not engineers so they do not speak the same language as an engineer.

Knowing the language of the audience is critical to communicating to them.

I spent 24 years with IBM and 15 years with Lexmark mostly being the go-between for the labs to the outside world. Both for current products and future products.

The NEC by definition states that the delivery is 240 VAC single phase. 120/240 is derived from taps at opposite ends of the phase cycle. Neutral is the defined middle of the phase and gives us the 120 VAC difference between the “A” and “B” phases. In your description, the “split phase” would actually be the Neutral, because it splits the high and low phase points at their center.

Also, the nominal voltage levels in the U.S.A. are 120 and 240 VAC. Canada is the same and I'm really not sure but I believe that Mexico may also use the 120/240 levels but I am equally sure that I might be wrong on that.

I wish I had my code book with me so I could give you the cite.

Cheers,

smoothy
Aug 11, 2010, 07:34 AM
donf,

No problem... I believe you do know your field... we do have differing terminologies we are used to from our respective fields. Not much different than doing business with someone in the UK, Australia, or the Caribbean. Yeah we all speak English... but the dialects vary substatually and its when you get into the details you notice it the most. Yeah... in both our fields we learn the same basic electricity principles... in electronics we learn to manipulate that electric, you guys learn the reliable, safe and legally acceptable ways to deliver it.

Have no idea what Mexico uses power wise. I am familiar with how its done in Italy... which won't be much different than the rest of Europe except for the outlets and plugs being different.

Trust me... Lucas... the Prince of Darkness had his hands in far more than just old British cars. Home (or Business) wiring over there will scare you.