The Neutral Wire

[clel miller]

Pardon my ignorance, but I have to ask an embarrassing question. How does current flow in the neutral wire if there is no voltage?
I have tried to look this up on line, but I have only been able to find info about AC circuits and not much about distribution. I would be very happy to read a link that answers my question, I realize it is very basic, but I just do not understand. For example, in a simple circuit with an AC source, and a light bulb, what causes electrons to flow in the white wire if there is no voltage??
Thank You

 

[bychon]

For the same reason and method by which current flows in the power line.

Keeping it simple by assuming perfect wire.

The wire carrying power to the light bulb has no voltage difference from one end to the other, and current flows to the light bulb. The neutral wire has no voltage difference between one end and the other, and exactly the same current flows. There is no voltage difference from one end of the wire to the other end because it has no resistance.

Making your point of view change usually kicks your brain into gear. Did it work this time?

 

[MikeMl]

If you take the cover off the panel in your house, you will find the Neutral line is connected to the ground stake, and to the cold water pipe. Practically, the Neutral is at 0V with respect to water-pipe ground. Line1 is 120Vac With Respect to N (or ground), and Line2 is also 120Vac w. r. t. Neutral; however, Line1 to Line2 has 240Vac. Instantaneously, the voltage on L1 is the mirror image of the voltage on L2. A 120V load is connected from L1 to N or L2 to N. A 240V load is connected L1 to L2 (sometimes with no connection to N at all).

 

[clel miller]

For the same reason and method by which current flows in the power line.

Keeping it simple by assuming perfect wire.

The wire carrying power to the light bulb has no voltage difference from one end to the other, and current flows to the light bulb. The neutral wire has no voltage difference between one end and the other, and exactly the same current flows. There is no voltage difference from one end of the wire to the other end because it has no resistance.

Making your point of view change usually kicks your brain into gear. Did it work this time?

Yes, I understand what you are saying. I guess I need to remember that the Neutral wire is part of the circuit, and not driving the lights (receptacles, etc.) all by itself.
Thank You

 

[Nigel Goodwin]

Yes, I understand what you are saying. I guess I need to remember that the Neutral wire is part of the circuit, and not driving the lights (receptacles, etc.) all by itself.
Thank You

You need to consider the 'reference', which is where you measure from. The live connection is no different from the neutral, both are a piece of wire connecting to a transformer, it's only the reference which makes then different.

Try thinking like this:

You're in your kitchen, standing on the kitchen table.

You measure to the ceiling, it's 6 feet, you measure to the floor, it's 3 feet.

You then jump to the floor, you measure to the ceiling it's 9 feet, and measure to the table, it's 3 feet.

Nothing has changed, but the measurements have - because your reference point has changed.

 

[Hero999]

There is a voltage across the neutral wire.

Use Ohm's law:
V = IR

Because the resistance is low, the voltage will only be very tiny.