Strange fault, can’t work it out

[Jed Turner]

hi there, first post.

I’m having a very strange problem affecting my entire board.

I’ve just qualified but not that experienced in faults.

My home electrics have been having problems lately, every time we use the kettle/ toaster/ hairdryer, the lights dim. If we have the toaster on and use the kettle the toast pops up. The shower is juddering when turned on. And the washing machine doesn’t spin if there is a load in it. The microwave also sounds like it has less oomph when lights are on or other appliances being used.

It’s almost like there isn’t enough power to the circuits however I’ve tested for voltage on the outgoing side of all breakers/ Rcd’s and I’m well within the +/-10% supply.

My boss said it could be a neutral fault, I tightened all the neutrals up and all other connections for that matter. I also tried a new 100a main switch incase there was high resistance going on inside this. Still problems, it’s not like it’s just part of the board having problems because I’ve tried all combinations of circuits being on and off and also tried appliances on upstairs and downstairs circuits all of them seem to be problematic. There is no tripping, just feel s like nothing is getting enough juice to run how it should.


Any ideas?
Thanks

 

[Octopus]

What earthing does your property have ?

 

[suffolkspark]

Thatl be a loose neutral somewhere nearby then id have thought

 

[Toneyz]

Thatl be a loose neutral somewhere nearby then id have thought

If its TNCS then it would explain why the ELI is high.

 

[Jed Turner]

Tncs

 

[Jed Turner]

Tncs, jointers in now. Running off a gennie

 

[richy3333]

Your on a TNCS system with an EFLI of in excess 9 ohms and your boss says it isn’t a problem? Am I reading that correctly?

 

[DPG]

Tenner says it's a bad neutral connection in the tee off joint under the pavement.

 

[DPG]

What did they find?

 

[Lucien Nunes]

Tenner says it's a bad neutral connection in the tee off joint under the pavement.

I don't think there's any evidence it's a CNE fault, I would expect it to be the line connection that is high-resistance. The EFLI will be bad, the voltage will vary, but there won't be any other symptoms like tingles off things.

But what was overlooked early on, is that any bad connection with enough resistance to affect things this badly, when loaded with heating appliances, will get pretty hot itself. If nothing upstream of the DB busbars was evidently toasty, then there would have been little doubt that that it was the DNO's problem even before getting the voltmeter out.

 

[DPG]

I can see your point there Lucien - there would be tingles felt if the neutral had a high resistance joint. Although if all accessories are plastic then this may be masked.

 

[Lucien Nunes]

Or, of course, that the equipotential zone is very effective and everything in the house is riding nicely on the faulty CNE. IIRC there was a thread on here with an open MEN in the street, where the only symptom was steam from the soil around a metallic water service that was shouldering the load of a few properties.

 

[DPG]

I've seen two failed neutral connections in tee joints under pavements. One was feeding my own property, and both were installed in the 1970s. DNO came out quickly to sort mine - piggy backed from next door neighbour''s meter cupboard with a temporary bit of concentric until the joint was fixed.