three breakers share one neutral and one grouding wires

[Doug Miller]

micky wrote in news: [e-mail]:

Maybe you should stick to subjects you know more about. If this is 3-phase wye, there's absolutely nothing wrong.

[Doug Miller]

philo? wrote in news:m4jaua$bmu$1@dont- email.me:

Note that you're also making the assumption that it's even a residence. The OP never stated that.

[John G]

\ You are correct, the neutral current will only be zero when all three phase loads are equall but the neutral current will never be more than the total on ONE phase when the other 2 phases have no current. Hence the wires would be quite acceptable if all were the same size.

It would be nice if the facts were quoted instead of blind assertions from limted sources such as Worldstandards" "three-phase electricity is rarely used for domestic purposes"

In fact 3 phase is very common outside the USA

[Ralph Mowery]

I also worked around lots of 3 phase of several differant voltages in industry. I did not make any asumptions when the OP said not in the US. I don't know very much about other countries. We did get in some odd ball (for the US ) 380 volt 3 phase equipment on a project about 25 years ago. No one told us and we were trying to adjust some 3 phase 300 amp heaters to

480 volts out. Most we cold get was 380 volts. Decided to check the incomming power and the transfrormers were set for 380 that the equipment needed.

Damn junk from other countries are going to get people over here killed. Seems that in the large 3 phase cabinets the disconnect is colored backwards from the old US. If the pointer is on Green, that means the power is off and it is safe to go in. If Red it means the power is on and it is not safe. We were used to seeing it the opposit, Red is off and green is when the power is on.

[philoÂÂ]

Wow

[philoÂÂ]

Three phase is very common in the US, just not in residential

[gfretwell]

Let; not start talking about triplin harmonics. Heads would explode.

[trader_4]

The OP didn't say it's a residence or give any indication at all as to wher e it's located. He did say it's not in the USA and IDK about you, but while I've traveled around the world quite a bit, I can't say that I've analyzed how the systems work even in the countries that I have visited, much less all the other countries.

[trader_4]

When there is more than one hot and they are not the same phase, a neutral doesn't have to carry the same current that the hots carry. That's how an Edison circuit, otherwise known as a shared neutral works. You see that used here, even in residential applications.

[philoÂÂ]

I assumed he was talking about his own house, but who knows.

Also: Even though at least one person here mentioned that three phase residential power is common in Europe it is still a safe assumption to say single phase is the most widely used /residential/ distribution system world-wide.

That said: It is probable that if someone from outside the US asked a question here...they very well may in Europe so my initial assumption could very well have been wrong.

My only experience with European power distribution was when I was stationed in Germany in the early 70's. Some of my friends had turn-tables that were designed for 60hz and Germany was 50hz.

Though they could use a step down transformer to give them 115v, the turn-table was too slow...so I had them wrap a few turns of electrical tape around the drive wheel.

[philoÂÂ]

It's not that complicated. In a three phase "wye" the center tap (even with unbalanced loads) would not draw any more current than that of the most used leg.

[Pete C.]

I seem to recall Switzerland was one of the countries that used residential three phase power.

[philoÂÂ]

From what I've found on-line I guess three phase is fairly common for residential in Northern and Central Europe.

Due to higher energy costs, Europe has been more energy conscious that the US.

The company I worked for (Enersys) manufactured industrial batteries and chargers. Some years back they bought out a French manufacturer of high-frequency conversion battery chargers which were more efficient that those being produced by the old Hertner plant in Cleveland. The Cleveland plant now builds the chargers used in the US...so it has all worked out well.

Three phase 460v would be rectified then converted to hi-frequency AC before it was sent to the transformer to reduce the voltage and increase the current.

In a standard battery charger the main transformer could be as much as

350#. The high-frequency transformers can be held in your hand!

The old chargers (both SCR or Ferroresonant) are still being made as their efficiency can be as high as 80%. The hi-freq chargers can get closer to 95% efficiency and had been made in Europe for 20 years before they started getting popular here.

[gfretwell]

That is where harmonics come in. The triplin harmonic would lag the voltage to the point where it would show up in the current of an adjacent leg For this reason, they sell "super neutral" cable with the neutral 2 wire sizes bigger than the ungrounded conductors. This happens where you have a large component of electronic ballasts and switching power supplies.

[philoÂÂ]

yes, that's true,

I guess I was thinking of just a resistive load

[gfretwell]

They are getting more rare every day.

[yyy378]

Thank you. That must be it.

[Seymore4Head]

The panel should be mark with it's type. You could post a picture of the nametag if you are unsure.

[yyy378]

I have seen same or similar panels used for single and three phases.

The panel has no writing of any sort. The electricians here don't even bother to label circuits for light, A/C, water heater, etc.

The panel and breaker are quite different from those used in the US. In the US, breakers get their power from the two bars in the middle of the panel. Here, you have to wire one breaker to the next. So, if the wire connecting breaker #5 and 6 is loose, breakers #6 and down will have no power.

[yyy378]

Oh, I'm in Myanmar. Here, you have single and three phases co-exist in residential dwellings, sometimes in the same building. And every house has a generator is the owner can afford one. Blackout happens several times a day. Every major piece of appliance is protected with a safeguard which cuts off the current if voltage is too high or too low, most of the time too low. The voltage is usually around 180 volt.