The Arcing Neutral

[La Poste]

Why do the Neutral connections seem to burn out more than the line?

Is it because the Neutral collects more debris, harmonics and all sorts of junk like that?

It seems that the Neutral conductor connections are the ones to watch and I am not sure why.

Any opinions are welcome.

Thanks very much.

 

[Engineer54]

It's not just the IT stuff these day's seems like anything that is electronic controlled these days will have these things fitted!!

Never installed 3 1/2 core cables to be honest, they had there uses, but were generally abused and basically installed for every application, even mains and sub-mains!!! I've condemned more than a good few of them in my time though!! ...lol!! Some have been in a right state too, having had to carry currents way in excess of what they were designed for!!

 

[spark 68]

I have built switchgear in the past where the Neutrals are rated at 200%, or the N busbars are doubled up WRT the Phase bars, these were usually for Datacentres (lot's of IT equipment).

 

[telectrix]

never had these problems when computers had valves in 'em.

 

[Darkwood]

Another area to look at is if said installation is a TNCS and also has a neutral earth fault somewhere in the circuits then its possible for eddie currents that can flow within the earthing systems between different premises to jump into the neutral which can effectively have devastating effects but usually taking out the weakest link in the system with overload burnout, also another area is incorrectly rated and doubled up busbar clamps usually 100a, 200a etc etc - the number of times ive seen 3 or 4 cables stacked up on one clamp with total disregard to it designed rating.

 

[barnzi]

Could also be down to EMC issues where you have lots of wandering currents finding their way back through the neutral conductor in the mains wiring... and that's before thinking about unbalanced phases!