Discuss Why am I getting a 420v supply from the power grid to my home when it should be 220v. All my applicances blew last night in the DIY Electrical Advice area at ElectriciansForums.net

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Why am I measuring 420v across the Live and Neutral feed into my home, when it should be 220v. My appliances have all blown
 
Have any of your neighbours had similar problems?

Have you contacted the supply company?
 
Classic symptoms of a broken N connection between supply transformer and yourself.
Call the emergency number for electricity supply company.
 
Classic symptoms of a broken N connection between supply transformer and yourself.
Call the emergency number for electricity supply company.
James, could you explain a little please? If the neutral is broken there is no return path so where does the 420V come from between L-N?
 
Ok, for instance the transformer feeds 4 wire, 3 phase and N down a row of poles a mile long, at the end of that run there are 3 houses.
Each house uses a different phase and the same N.
All works well, N is bonded to 0v , normally the star point of the transformer windings. max of 240v from the star point to each phase conductor

If the N cable breaks along that mile run, the houses at the end of the run are still sharing the same N connection but now it is not tied to 0v
Depending on what loads are connected to each phase, the N voltage will drift towards the phase voltage of the phase with the lowest resistance load on it.
The effect is that the N conductor voltage floats seemingly at random from 0 to 400v relative to a phase voltage. (0 to 240v relative to earth)

It is more common to happen in rural locations where the supply cables are separate and 1 can be broken without affecting the other cables, but it is not unheard of in towns etc.

If you end up with a farmer on the phone saying can you have a look at my electrics, the lights keep going bright and then dim as if they are possessed, tell them to turn everything off immediately before things start to go bang!!
 

Reply to Why am I getting a 420v supply from the power grid to my home when it should be 220v. All my applicances blew last night in the DIY Electrical Advice area at ElectriciansForums.net

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