return path of current through neutral

Thread Starter

Fintan

Joined Feb 22, 2007
2
I am having difficulty understanding whether the return current on a neutral branch circuit condutor entering a electrical panel goes to ground or returns to the transformer on the distribution line suppling the residence. Can anyone out there please educate me:confused: :confused:
 

thingmaker3

Joined May 16, 2005
5,083
If you don't live in the USA, ignore the following paragraph.

It goes to ground. If you open up a breaker box, you can visually verify that your neutral conductors are tied to the same bus network as your grounding wires. Your hot wires (red and black) go to the transformer.
 

Thread Starter

Fintan

Joined Feb 22, 2007
2
Sir, could you please expound on your determination that the the neutral returns to ground and why geography has a role in your responce to the question. My assumption was that it did return to ground but I was confused by a text book that stated otherwise. Furthermore, the more I read about electrical principles the more I become confused. Is there an easy way to understand the principles of electricity. Can they eplained in layman terms without comprimizing the integrity of the principles?
 

kubeek

Joined Sep 20, 2005
5,794
The geography has a role there because in USA it is probably different than in other countries, like in europe.

For example where I live we have the current returns through the neutral wire, which is I guess connected to Earth in the distribution transformer.

In both cases it goes back to the transformer, either through the neutral wire or through Earth.
 

wireaddict

Joined Nov 1, 2006
133
Actually, there are 2 paths for neutral current between a transformer & the main building power distribution panel in the USA. There's the main path through the neutral conductor which is hard wired between the neutral bus in the panel & the center tap of the transformer secondary & also, there's a ground path; the neutral/tranny secondary center tap are grounded at the pole or pedestal & the neutral in the main building panel is also grounded.
 

tejasvi

Joined Feb 4, 2007
2
The geography donot have any role play here, There are some standards.

Ground wire is terminated with the neutral at the generating station only.
Current carried by the ground conductor is usually small, because this current is mostly due to the stray capacitance between the circuitry and the chasis ( chasis is connected to ground).
 

thingmaker3

Joined May 16, 2005
5,083
I speak of what we have in the USA because I don't know what they have in other nations. I don't know what the standards are in the other nations.

The National Electrical Code, adopted by all fifty states with some modification, requires all of a building's neutral wires and ground wires (the grounding conductors and the grounded conductors) to be tied to a bussbar in the breaker box. This bussbar is in turn required to be well grounded by a conductor connected to an electrode buried in the earth. The same bus also has a conductor from the neutral of the transformer.

It sounds a lot more complicated than it really is. We're grounding the transformer neutral lead. We're also grounding a separate ground lead because our split phase system is prone to imbalance, which will produce voltage between the neutral lead and ground if there is any poor connection in the neutral path.
 
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