Low Resistance on IR Testing

[JohnW2]

Lets see what TLC come back with, tomorrow I will crack on with live tests and see what happens. .... On paper the current tests all pass, so im not going to butcher the house to replace something on the off chance. .... Hopefully TLC and manufacture come back with an answer.

Any developments?

Kind Regards, John

 

[wcavanagh]

TLC have passed the sample onto the factory and we are still waiting on their findings.

 

[Risteard]

On paper the current tests all pass

It is worth remembering that the minimum values for insulation resistance do not pertain to any circuit or section of cable, but to the entire installation in parallel (or for large installations each distribution circuit with all final circuits connected in parallel).

If you do not measure the insulation resistance for the entire installation (or distribution circuit with all final circuits connected) then you must calculate the resistances in parallel to determine whether the Requirements of the Regulations have been met.

It is also a Requirement that the earthing arrangement is in circuit during testing.

 

[JohnW2]

It is worth remembering that the minimum values for insulation resistance do not pertain to any circuit or section of cable, but to the entire installation in parallel (or for large installations each distribution circuit with all final circuits connected in parallel). If you do not measure the insulation resistance for the entire installation (or distribution circuit with all final circuits connected) then you must calculate the resistances in parallel to determine whether the Requirements of the Regulations have been met.

All true. However since (I think) the lowest IR the OP measured on any final circuit was around 50 MΩ, unless he has 50+ final circuits (which I would suggest is a little unlikely in a domestic property), the overall IR should be reg-compliant.

Kind Regards, John

 

[JohnW2]

TLC have passed the sample onto the factory and we are still waiting on their findings.

Any news yet?

Kind Regards, John

 

[securespark]

Is your cable marked BASEC?

 

[Kablo]

TLC have passed the sample onto the factory and we are still waiting on their findings.

 

[Kablo]

Did you ever get a report back from the factory?
I'm not an electrician but an ordinary householder but my house was rewired four years ago with the same cable and it's just tripped. My new electrician has replaced some of the faulty cable and he said the insulation had failed.

 

[wcavanagh]

Totally forgot to update this, yes it turned out to be a faulty batch that they did recall, but for some reason TLC didn't get the recall. I have received compensation, etc. I have left the cable in, as the readings are OK according to the permitted max. I have had no issues at all, and as its my own house, easy to keep an eye on. The amount of destruction needed to replace is not an option just now.

 

[SimonH2]

That's the big problem - the cost and disruption to replace it. I bet the compensation doesn't come close to the real cost, let alone the intangible cost of the disruption.

 

[bernardgreen]

There was a similar "event" in Australia when sub-standard cable was installed in hundreds of homes and businesses. Very large bill for replacement

https://www.accc.gov.au/update/infinity-cables-frequently-asked-questions

and in the UK in 2015

https://www.voltimum.co.uk/articles/faulty-cable-leaves-woolworths

The Approved Cables Initiative (ACI) is reporting that Woolworths [ distributor in Australia ] may face a clean-up bill of between £16 to £32 million for its role in the sale of faulty electrical cable to around 40,000 households and businesses. This major problem has occurred in Australia, but the risk is that it can happen in the UK:

 

[wcavanagh]

That's the big problem - the cost and disruption to replace it. I bet the compensation doesn't come close to the real cost, let alone the intangible cost of the disruption.

You know it, lucky for me its not a massive deal, but it is what it is. Me and the Mrs will get a little break out of it, so cant complain, too much

 

[Kablo]

What does and who is TLC please?

 

[bernardgreen]

TLC

Tender Loving Care for the stressed out trades(wo)man or a nationwide supplier https://www.tlc-direct.co.uk/Information/contact/ContactList.htm#crawley

 

[Kablo]

I have contacted BASEC who said there wasn't a problem in 2014 as far as they know with this cable but they were waiting for a contact to come back to them.
I don't understand if there was a recall on this cable that BASEC don't know about it.

Of course, both our problems seem to have been now, four years later.