Is 4mm earth acceptable for a TN-S?

[nicks electrix]

Hi Forum.

First of all thanks to everyone who gave advise on 2391 exam, the wait is over and i passed. I m being assessed at the end of August and i have left my project a bit late. I was going to upgrade the fuse board in my house until today i realised it was a TN-S supply and the earth is +-4mm. what is the best way to get around this situation? Would the assessor be happy with an earth clamp on the lead sheath or not? I have done a lot of work but its all about 45min drive from my office/home.

Thanks

 

[danny7299]

How Is the earth connected to at the mo ?

 

[Sidewinder]

nicks,

Chuck the adiabatic at it to check.

 

[Badger]

if thats the earth the dno have supplied, and as long as when you test for earth resistance on incoming earth ZE it is below 0.80 ohms then id say its not really your responsibilty, phone dno if you have problems but other than that just upgrade your consumers side to the earth block or MET

 

[danny7299]

We have used these before

http://solutions.3m.co.uk/wps/portal/3M/en_GB/ElectricalMkts/ElectricalSupplies/ProductInfo/ECatalogue/ElectricalEarthing/EarthBondingKit/

I would say a 4 mm is too small to take fault current for a length of time but as above you would need to check , personally for an assessment I would over do it and bang in 25mm tails and 16mm earth

 

[Badger]

 

[nicks electrix]

How Is the earth connected to at the mo ?

The 4mm cable is soldered to the earth sheath and to the met. From the met to the consumer unit it is 16mm.

 

[Sidewinder]

Ah, then Badge is spot on leave it as is, it is the DNO property!

 

[Badger]

Ah, then Badge is spot on leave it as is, it is the DNO property!

:Salute

 

[Sidewinder]

You taking the p*? :^O ROTFWL

 

[Badger]

:^O