ARE LIVE AND NEUTRAL WIRES DIFFERENT IN COMPOSITION?

[Pastory]

Hey holly electricians, I am asking are live and neutral wires different in composition or same but just some different colors of insulation. Was one type of wire just designed to carry electricity and the other to be a neutral one.? Are they different in composition? For testing purposes if I connect red (live) wire on a position of black(neutral) wire that means if I interchange them, will there be any problems?

 

[radiohead]

Hey holly electricians, I am asking are live and neutral wires different in composition or same but just some different colors of insulation. Both conductors are of the same copper and same cross sectional area Was one type of wire just designed to carry electricity and the other to be a neutral one.? They both carry current. If a current of 10a flows in the line conductor the same current will flow in the neutral. Are they different in composition?No For testing purposes if I connect red (live) wire on a position of black(neutral) wire that means if I interchange them, will there be any problems? Yes, you'll probably kill yourself or someone else.....what possible purpose in testing would interchanging L + N wires serve?

By the way, both conductors are termed 'live' in the UK. The correct terms are line and neutral. Both are deemed to be energised and live.

 

[telectrix]

the conductors are identical in size and compostition. generally copper, but aluminium is sometimes used. both the L and N conductors carry the same current as an imbalance caused RCDs to trip.

 

[pc1966]

For testing purposes if I connect red (live) wire on a position of black(neutral) wire that means if I interchange them, will there be any problems?

It depends.

As mentioned above, both conductors are considered "live" as they carry power, but under normal circumstances only the line (L) is at a voltage that is dangerous compared to that of the Earth around you.

I see your details say Tanzania and I do not know your electrical regulations, but assuming they are similar to the UK's due to historical connections then another factor has to be considered and that is the practice of only having fuses on the L path, and often only switching the L path.

As a result, while something like a light bulb won't care witch terminal is L and which is N, the reversal of the supply can result in a dangerous situation as the overload/fault protection of the fuse, and the means of isolation of the switch, are not removing the high voltage from the load. They are simply stopping the current from completing the loop for normal operations.

I.e. normally if you switch something off, or the fuse blows, then it has no L connection any more, but it still has N connected and is all internally at the N potential. This is close to the Earth in potential (as N is connected to the Earth back at your substation or similar point of supply) so relatively safe.

But if L & N are swapped, switching off make the load look "dead" as a light goes off, heater cools down, etc, but everything is now sitting at the L potential and so dangerous to touch or for any other fault.

So while the only difference between the L and N conductors in terms of their physical construction is the colour of the insulation, they cannot be considered interchangeable electrically as under fault conditions the safety implications are quite different.

 

[Lucien Nunes]

Normal wiring cables have line and neutral cables of identical construction, just different colours. But there are some specialised cable types, such as split concentric cables used for distribution work, where the insulation of the neutral is not as robust as that of the line, because it is not intended to be at significant voltage with respect to earth.

 

[SJD]

I had in mind that split concentric cable was often different conductors for L & N, e.g. per attached image. But I've no idea how common this is (in the UK or anywhere else).

 

[Dave OCD]

That looks like Concentric rather than Split Concentric as the neutral cores are insulated in the split variety, about half and half with the bare cpc cores. And that line conductor in the picture looks like aluminium ?