120vac & 220vac

The cost is dependent on the power used(watts) and watts is = to volts times amperes so let's say if you have a motor with 120 vac and draws 5 amperes = 600 watts. then you have a motor that is 240 vac and draws 2.5 amperes = 600 watts, you see they are the same so the cost is the same, however you will notice that with the higher voltage the ampres are less therefore a smaller conductor can be used. So the cost of transmission of electricty is less for a higher voltage.

Also pay attention to Hz. 60 Hz here in the US and 50 in the EU (I think).

Tesla came up with the 60 Hz. When I was younger fluorescents gave me headaches from the flickering. Europe had a reason for the 50Hz but of the top of my head don't remember what it was.

We use 240 2phase and you split the 2 legs into 120 1phase. But you probably know that.

Brad

We use 240 2phase and you split the 2 legs into 120 1phase. But you probably know that.

i thought you gave up 2 phase system when you went to the grid system in the 60's

do not the U S use 1 phase of the 3 phase to make 110/220 single phase

Business gets 3 phase, residential (most) get 2 phase (2 hots legs and a common) wiring up the wood shop this morning. Stove, dryer, furness, all get 240 and the outlets and lights are 120. Actually it measures 117 at the socket most of the time.

Are you measuring RMS or peek to peek?

Brad

"Business gets 3 phase, residential (most) get 2 phase (2 hots legs and a common)"

Please get your facts straight before posting. We do NOT use "2-phase" for residential services in the US. We use Single phase, 240V with a center tapped winding taken to ground that gives us a neutral, which nets two legs of 120V single phase. 2-phase power is a completely different thing. It is a polyphase system wherein each phase is 180 degrees out from the other, and requires 4 wires for distribution. It was used in a few light industrial areas of the US and there still are the odd pockets in use, but it is almost completely obsolete now.

People like you who misconstrue and continue to pass on your incorrect information serve to perpetuate the problem.

Ok I stand corrected: Now explain, "We use Single phase, 240V with a center tapped winding taken to ground that gives us a neutral, which nets two legs of 120V single phase. 2-phase power is a completely different thing", so I understand how 2 120v single phase use the same common for return.

That would be 240v peek on one wire if they are one the same phase, if I'm not mistaken. A good reference book would be fine. My wiring is all to code. So I would like to understand where I'm confused as to it workings.

"People like you who misconstrue and continue to pass on your incorrect information serve to perpetuate the problem" and in turn people like you make them fear to be corrected perpetuate the problem.

When I see fault in others I try to look at my self to correct my own faults. This not criticism only a feed back system. And I thank you for pointing out my error. The admonishment is counterproductive. Understanding the dynamics of a system is vital to use a system well and to constructively build on it.

Never mind just got straitened out by my electrician I still don't understand compleatly but I will. He keeps me to code and I keep his computers at optimum.

Thanks again

Brad

JRaef I Apologize Most of this reply should have been sent directly to you not to the forum. Bad tact on my part. Mornings are not my forte but i know better. Brad

I probably could have used a little more tact myself. My return apologies.

I had been involved in an earlier thread where some putz told someone to try out his theory by connecting the two lines of 240V together and then to neutral on a heater (I think), which would have of course been a dead short. His claim after the fact was that the circuit breaker would have tripped and prevented a fire, but that was incredibly stupid for him to suggest it. There are a lot of "uninformed" people reading this forum, a few of which may have taken him seriously. I should not have projected that anger into this thread.

No offence taken and I'm relieved none given.

Sounds like he needs a class Z fire extinguisher in his tool box.

He is going to need all the help he can get to make that work.

Better yet video tape it for what not to do and why.

Thanks again

Brad

AMEN brother. I had a squabble with a kid from California and an Aussie about single or split phase for residential. I finely just un subscribed from the discussion. Please speak LOUDER for everyone to hear.

James

And it's a good thing, too...'cause several years ago the contactors module in the control box for my 5HP irrigation & domestic water pump needed replacing. Now, in the original contactor unit, not only was 240VAC relayed for use by the pump, but the coil was also 240V. Problem was, the only replacement contactors any-longer/locally available had only 120V coils. There being no time for a (possibly fruitless) search and ordering of total-240V contactor module that might still be in production, there was not choice but to go with the 120-V-coil, 240V contactor module...before dishes piled too high, BO from no shower, and such...

When hooking up...., I first verified the two legs which referenced 120V to ground and 240 to each other. Next, one "hot" leg was connected across pressure switch and contactors coil (and returned to GND). This left an unused hot leg. Since the control box was supported on the pipe containing the down wires to the pump it was deemed a suitable earth ground; so the open leg was simply connected to the metal control box. The new contactor module, and replacement modules since, have all worked just fine.

You're right...nothing remarkable here. Just thought someone might find interest in seeing a practical application of what all the fuss was about.

Signed,

That other kid from California.

That other kid from California,

Not to argue but,

This left an unused hot leg. Since the control box was supported on the pipe containing the down wires to the pump it was deemed a suitable earth ground; so the open leg was simply connected to the metal control box.

That makes no sense. Sorry

Brad

As an electrical contractor, I might need to use a spare wire like this as a ground, if none was ever installed. Older systems can use colored tape to identify wires. Green would be used on both ends approximately 6' in length. This tells the next electrician it is a ground wire. Both ends would be grounded. White tape indicates a neutral. If I need to identify 480 three phase we would use Brown,Orange & Yellow. This is not all the colors, but you should see the situation.

James

They way he wrote it it sounds like he is grounding his unused hot leg. I assumed not but that is why that doesn't make any sense.

Marked they are to code.

Unmarked they are a pain.

Brad

Your right. Sometime you open a junction box full of wires with no markings and think, Oh s---. A good electrician will write the circuits on the box cover with a "sharpie" marker.

James

<....50 in the EU (I think)...>

Correct.

There are some oddities elsewhere in Europe. For example, the Swiss national rail network has places where 16²/₃Hz is used!

Why, do you suppose? The Swiss rail net that is. Is that rail power or overhead?

What I mean is, thrice 16-2/3 totals 50Hz. It's as if the rail grid is "tapping" the domestic grid as a sub-grid...and that anywhere the railway runs. So maybe it's for purpose of power redundancy...i.e., single point failure failsafe...and reliability of trains running on time? We all know about those Swiss when it comes to time keeping.

What aboout public safety? Does that factor in?

Not really; provided wiring, fixtures, outlets, switches, etc. are designed and rated for the appropriate operating voltage.

Yes, I can see that. Perhaps I should have said personal, instead of public, safety--meaning...the hazard of potential contact with Nom. 220VAC as opposed to 110.

From an historic perspective it occurred to me that during the early years of nationwide electrification, the United States was not only much more expansive and unsettled geographically, but much of its population was relatively "poor and backward" by European and British standards--at least those farther from east coast urban centers. During those times, standards and codes enforcement, where either existed (in the new world), were probably much more lax than now; surface wiring was more prevalent; houses were commonly constructed and maintained by owner occupants; the U.S. was still only approaching universal literacy; insulating materials and electric component safety features weren't what they are today; plastics had barely emerged....

In Europe and the Isles on the other hand--apart from the contrasts mentioned above, it would seem that in-home electric service was probably something enjoyed largely as a matter of social standing in terms of money, privilege, and class -- enjoyed by the kinds of (well-schooled) folks who would not be doing their own installation or repair service.

Naturally, many people States-Side initially think of the 220V "continental" system as peculiar; no doubt those in the old countries think likewise about the U.S. system. But it occurred to me that there must have been some valid reason when it all got started...so perhaps a perception early on, that to accidentally contact 110V is preferable to contacting 220V, might have led to an "expert" consensus that voltage should be stepped down at the entrance of American dwelling places. On the other hand it could simply have been a matter of big manufacturers calling all the shots--whatever served their commercial purposes served consumers as well(?).

So as a non-expert, I was basically looking for some history based justification, safety-related or otherwise, as to why the same electric delivery system was not adopted universally. To the degree this could be considered "off-topic," apologies.

These are, the simple facts- apart from transmission wire cross section- the human animal is electrocuted much more from higher emf ie 220-240v, as against 110-120v- ac is less dangerous than dc at these levels- that is the benefit of 110-120v domestic power as against 220-240v power.

Thanks...