three breakers share one neutral and one grouding wires

I ask an electrician to install several outlets on three breakers. I found that the electrician uses only five wires in the trunking. Apparently, there is one grounding, one neutral and three hot wires. The grounding and neutral wires are shared by three breakers.

How safe is it to do it this way? (Please forget about NEC as this is not in the US.)

Reply to
yyy378
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Sounds like 3 phase wye. You see that here in the US but only in commercial. If they have 3 phase in residential there, that is what you are looking at.

Reply to
gfretwell

It's not right

Reply to
philo 

It's not right that he asks a question and only says that the location is not in the USA. Some kind of secret or a troll?

Reply to
trader_4

Who knows, but no matter what country he's in that method would be incorrect.

With three circuits, at least two of them would share the same "hot" wire with the neutral having to bear (up to) twice the load that it's rated for. This assumes all wires are of the same gauge and rated for the same current as the breaker.

Reply to
philo 

It could be OK. It might be a 120V circuit and a 240V circuit. Not enough info to tell. One breaker would have to be a double pole type.

Reply to
Seymore4Head

Except he said "three" circuits and a total of five wires. 3 hot, 1 neutral, I ground

Putting code aside, from a purely safety stand point it would be safe only if the wires were double the gauge required... and that /not/ all three shared the same "hot" side. I rather doubt that's the case.

Reply to
philo 

Unless it is in fact three phase e.g. 120/208 or 277/480 and all hots are o n different phases.

nate

Reply to
N8N

Yes, but very unlikely to see 3 phase in a residence.

Only once have I seen it...and it was simply because the people had purchased a small warehouse with an elevator and converted the building to a residence.

The three phase circuitry was completely separate from all other wiring and used exclusively for the elevator.

Reply to
philo 

Not if they are on different phases, eg an Edison circuit. Which again is why you need to know the rest of the story.

This assumes all wires are of the same gauge and rated for

Reply to
trader_4

Has anyone ever seen a residence with three phase?

What's an Edison circuit? He did not believe in AC

Reply to
philo 

There are lots of countries that have 3 phase in a dwelling

Reply to
gfretwell

From "Worldstandards"

"three-phase electricity is rarely used for domestic purposes"

Of course that does not mean that it is /never/ user but I think the OP has been scared off now

Reply to
philo 

philo? wrote in news:m4i891$v71$ snipped-for-privacy@dont-email.me:

Wrong. This is perfectly fine if it's a 3-phase circuit.

Reply to
Doug Miller

philo? wrote in news:m4ibjs$cvp$ snipped-for-privacy@dont-email.me:

What part of "this is not in the U.S." did you find confusing? And who said it's in a residence? Certainly not the OP.

Reply to
Doug Miller

AIUI, grounds are grounds are grounds.

But neutral wires are conductors of electricity, the same amount that the hot wires carry.

Did he only use ONE neutral wire for all the outlets powered by three different breakers? So for example, the breakers will provide 15 amps each, 45 amps total, and the only neutral wire has to return up to

45 amps!!!! You can't carry 45 amps on 14 gauge or even 12 gauge wire, so no, it's not right.

What about the FEC, the Foreign Electrical Code?

AFAIK, the NEC is based on reality, and doesn't disapprove of things that aren't unsafe, at least somewhat**. Maybe that's not always true, but anything it says about this sort of thing probably does relate to safety.

**Small risks that people would take, or that they didnt' even know about , 50 years ago aren't permitted anymore, but why should non-Americans bear these risks when they are known now?
Reply to
micky

I didn't think of that. But if it were a 3-phase circuit, could one wire accurately be called "neutral"?

Reply to
micky

micky presented the following explanation :

Pity some of the contributors here know nothing about 3 phase electricy.

The OP said 5 wires which is exactly the way Electricity is distributed in Europe Australia and many other countries.

15 amps in each phase seperated by 120 degrees results in NO NIL NOTHING in the neautral wire.

Admitadly not all domestics get 3 phase, I have 3 phase because I hava a split system Air con and so do many of my neighbours. My previous house did not have A/C until very late and then the supply was changed to 3 phase.

The NEC is based on the archaeic Edison system and so is not the Bible for more advanced systems. :-Z

Reply to
John G

I worked with it industrially for 38 years few of us here (myself included) made the assumption that the residence was three phase...though as pointed out...it could be.

The OP did not give enough info for anyone here to know.

Now, if it is a three phase "wye" feed and there are a total of three , single phase outlets the neutral current would not be zero unless the loads at all three outlets were the same...however...if it is three phase, then the electrician probably did wire it correctly.

Reply to
philo 

micky wrote in news: snipped-for-privacy@4ax.com:

Yes, if it's 3-phase wye, which can have a total of five wires, just as the OP described: ground, neutral, and one for each of the three phases. Phase-to-phase voltage is 208V, and phase-to-neutral is 120V, in a typical North American installation.

Reply to
Doug Miller

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