what is neutral wire ?...start from the distribution pole and also end it there?

Question

i wish to have a cleare picture what is actually going there .

Answer 1

The Neutral wire is connected to a center-tap of a 240 Volt transformer winding (In a residential application). This makes it possible to get 120 volts from either end of the transformer winding to the neutral. Normally, the neutral or "Grounded Circuit Conductor" is connected to ground at the electrical service panel. This establishes a ground reference of zero volts at the center of the transformer winding, which limits the voltage to ground at the ends of the winding (The hot or ungrounded conductors, which are also called "Phases") to 120 Volts each. That is for safety, since if you grounded one end of the winding instead of the center, the voltage to ground at the other end would be 240 Volts (Ouch).

The neutral conductor provides a path for current flow for 120 Volt devices you connect, since the only place you can see 120 Volts is from neutral (Center tap) to a hot lead. Take a clothes dryer for example. It has three circuit conductors, both hots and the neutral. The clock which controls everything is commonly rated for 120 Volts, so it is connected from neutral to one of the hot leads, (A phase this time) and draws 1 Amp. The motor and the heating element might both be rated for 240 Volts, so they are connected between both of the hot leads (A and B phases, no connection to neutral). If the Heating element draws 15 Amps, the Motor draws 3 Amps then: Phase A carries 19A (15 + 3 + 1), Phase B carries 18A (15 + 3), and the neutral carries only the 1A required by the clock.

The neutral carries the unbalanced load any time the current on leads A and B are unequal. Example, everything in your house is shut off except 2 devices. One is a 120 Volt heater connected between A phase and neutral that draws 5 Amps. The other is a 120 Volt quartz work light connected beween B phase and neutral which draws 3 Amps. Each phase carries its own load, the neutral carries (5 - 3) or 2 Amps back to the center tap of the transformer winding.

Answer 2

Neutral wire is like the 'collector' for current. Current is given through a wire that is called as live wire and given back through the neutral wire. In a single phase system, there is no difference at all between live wire and the neutral wire and both are equally dangerous.

However, take a three phase system which is extremely common. Here, all three phases : R, Y and B are given through 3 seperate live wires and all are collected back through the neutral wire. In a balanced case, the current through the neutral wire should not carry any current. Neutral wire is normally denoted by black and R,Y and B wires by the colours red, yellow and blue respectively. Green is used for ground in cases where grounding is provided.

If you want to connect a component to the R phase, you have to connect it to the R wire and then to the neutral wire. For Y phase, connect it to Y wire and the neutral wire and so on. In case of single phase, the live wire and the neutral wire have the same function and you can consider them as the two ends of an AC supply.

Answer 3

In modern house wiring, the neutral wire is connected to ground at the breaker box. It is at zero potential to earth. You cannot get shocked by it nor treat it the same as the hot wire.
That said, in a long run from the box, the potential of the neutral might rise to a volt or two due to resistance of the wire.

Answer 4

A neutral wire is one of the “live” wires in electrical systems, the insulation of the neutral wire is coloured white or grey in the USA, or blue in the UK and rest of EU. It is most often connected to earth at the Service Panel in the USA. And should not be so connected anywhere else within a building so as to not create a hazard. The neutral is connected to the center tap of the secondary winding of a single phase transformer of the power company. It is the connection of the center point of a polyphase wye transformer commonly used in commercial and industrial systems.