cable behind 50mm insulated plasterboard

[Silly Sausage]

If it had no RCD would there not be another type of protection?
What about what the DNO put in their cut out thingys, what are they called?

No idea, I've never seen inside one!

 

[trev]

Unfortunately on a TT the dno fuse is unlike to operate due to the high impedance.

Cheers

So the trick is to make sure the impedance is low enough that any fuse will operate.
It's not difficult, I do it all the time. My own home is on a TT and has a sub 1 ohm impedance. If memory serves me well it's around the 0.5 - 0.6 mark (can't be bothered to go and get the cert) my record is 0.29.

 

[GEOFF S]

So the trick is to make sure the impedance is low enough that any fuse will operate.
It's not difficult, I do it all the time. My own home is on a TT and has a sub 1 ohm impedance. If memory serves me well it's around the 0.5 - 0.6 mark (can't be bothered to go and get the cert) my record is 0.29.

Impressive, are we talking Ra or Zs?

Hot or cold site?

Cheers

 

[trev]

Well if we want to be pedantic it's actually a Ze although the terms are interchanged all the time when talking about TTs. Ra is the resistance of the electrode itself measured with the spike system. The 0.29 was a domestic

 

[GEOFF S]

Well if we want to be pedantic it's actually a Ze although the terms are interchanged all the time when talking about TTs. Ra is the resistance of the electrode itself measured with the spike system. The 0.29 was a domestic

Well to be pedantic, where RA isnt Known it may be replaced by Zs, 411.5.3. So the RA was 0.29 ohms?