CU replacement advice needed

[PrenticeBoyofDerry]

Also I wonder if there is any regulation on the length of earth wire allowed from CU to my spike? The meter is about 2m from the cu so a 3m tails kit will be fine but I doubt the 3m earth will be enough to get from cu to spike

That will be accessed and tested by your electrician.

 

[mfarrow]

The short answer is no though.

 

[ekmdgrf]

I'm yet to hear of an installation losing the suppliers neutral only in all many years. Even if the neutral were lost, what hazard would it pose on a TT supply?

I vaguely recall mention of this being caused by someone t'iefing the supplier's neutral conductor:

http://www.bbc.co.uk/news/uk-england-leeds-14075618

Although I can't find any report that actually explains how the deflagration occurred.

 

[Adam_151]

Although I can't find any report that actually explains how the deflagration occurred.

I should imagine its a case of a row of properties on TNCS, neutral disppears and suddenly the water and gas services end up being susbitute neutral conductors, all you need then is a corroded bonding clamp in a property and it'll heat up, perhaps arc and bit and melt a nearby solder joint and allow gas to escape.

 

[bernardgreen]

There is bit more public domain information here

http://www.westyorksfire.gov.uk/news/blast-footage-prompts-warning

It is possible that the fires were started by earth wires between service pipes and MET overheating. These would have a small cross section area compared to that of the metallic service pipes.