UK Running Neutral Wire from consumer unit to Ground henley block

[James1985]

In the UK, It is said that the neutral wire is connected to ground/earth wire along the way back to the substation.

Ive inherited a setup where the incoming SWA neutral wire is hard to join/reconnect to as the previous electrician hasn't used a henley block due to limited space... therefore the neutral wire is fixed from SWA entry to point B, with no busbar/henley blocks

In this situation, I am wondering what the problem would be to run my Neutral cable from my consumer unit directly to the earth henley block?

My reasoning is that the Neutral wire connects to ground at some point further down the line anyway, so whats the problem?

 

[James]

This is a job that you should be asking an electrician to quote for.
it may also need the services of your electrical supplier to fit an isolator.

what you are suggesting is not allowed and potentially dangerous.

 

[James1985]

This is a job that you should be asking an electrician to quote for.
it may also need the services of your electrical supplier to fit an isolator.

what you are suggesting is not allowed and potentially dangerous.

Hi James, I understand the regulatory side of it, However Im asking the question based on the actual science/physics behind it all, is it fine to do, if not, why?

 

[plugsandsparks]

Earth burns out - all metal in property rises to 240V, everyone dies

 

[Lucien Nunes]

To elaborate... a protective earth conductor is only supposed to be used to maintain an equipotential on exposed metalwork, not to carry significant current unless there is a fault. A neutral is the opposite - it's allowed to carry current but mustn't be connected to anything exposed, in case it breaks or goes high-resistance in which case the exposed parts become live. The two functions, PE and N, are only allowed to be combined into a PEN where the nature of the cables and the work carried out on them makes them unlikely to become high-resistance or open-circuit. This means that in the UK, it is restricted to the DNO's equipment and a combined PEN is not generally allowed in the consumer's installation because there's too much risk of it being wrongly disconnected.

By connecting your neutral to the earth block you would be converting the supplier's earth into a PEN which would possibly work, but is forbidden by BS7671, by the conditions of the DNO who work to the ESQCR, and might nonetheless overheat and fail dangerously because the CSA might be smaller than that of the proper neutral.

In some locations, e.g. the USA, the procedure is different and the neutral and earth are connected together (they call it 'bonded' which has a different meaning in the USA) in the consumer unit, not the DNO's equipment. But in that case it is the earth using the neutral, not the other way round, so you can be assured that it will handle the full current which a UK supplier's earth might not.