Which burn/overheat more often, Lives or Neutrals?

[CAWORK]

Evening all,

I have heard a few other times in the past about burning etc always going for the neutral especially shower units/switches, immersions and main switches etc.

Is this true or just pure coincidence?

I read an iee article on it before as well, in the topic saying that the same goes for neutral brushes in washing machine motors etc as well.

regards

 

[Spark123]

Shouldn't really matter, I suppose there may be some psychological explanation as in people not thinking the neutral is as important as the phase so not tightening as tight as the phase.

 

[Lectrician]

It is scientifically proven that neutrals do go high resistance, and hence burn out, more often that the lives.

You need to be a physician to explain it, but it is very true.

On overhead supplies it is 99% of the time the neutral which rots, causing high resistance neutral and flicking lights etc. In many cases it can be at the final drop to a property, and the earth is also then lost.

I have seen plenty of lost neutrals on PME properties, a couple with near shocking outcomes. I am sure many others have seen the effects of lost neutrals too.

 

[TicklyT]

Could it be because neutral is bonded to earth, so it can allow DC currents to frow round a neutral - earth loop, and electrolytic corrosion?

Could this also occur in CPCs, but may go unnoticed until something else goes wrong?

IIRC it used to be common practise to bury large masses of scrap iron around telephone exchanges, and purpousely introduce a DC current between this sacrificial anode and lead cable sheaths to reduce electrolytic corrosion of underground cables.

Electrolytic corrosion was more pronounced when lead cables ran parallel to railway lines, even more so when said railways used DC electric traction.

 

[toasty]

TicklyT,
I had heard similar stories, although I was told they used bags of magnesium scraps.
But as you say, to act as a sacrificial anode.
Don't they do the same thing on large ships? I think they bolt blocks of more reactive metal to the sides.
And hot water cylinders, some have a sacrificial anode in them too.

I think you are probably right.

While we are on the subject, isn't that the main reason why cars went from being positive to negative earth? That was something to do with corrosion too.

Cheers
-Dan

p.s Nice question OP. A refreshing alternative to all the squabbling

 

[TicklyT]

TicklyT,
I had heard similar stories, although I was told they used bags of magnesium scraps.

I think magnesium would have been ideal, making it self - powered. Scrap iron was a cheaper option, but required addition of a DC current to make it work.