20 amp mcbs on 2.5 radials

[thekingiam]

Done a eicr on a tt no rcd protection and ze of 268 ohms.
3 Radials in 2.5mm going to 32 amp mcb.
Just been plastered throughout and some type of rewire i think, the house is going through a sale and was requested by buyers solicitor.
I was going to replace cu and put sockets on three seperate 20amp mcbs voltage drop not a problem as house is tiny.
Any problems cAn you see

 

[Pete999]

Done a eicr on a tt no rcd protection and ze of 268 ohms.
3 Radials in 2.5mm going to 32 amp mcb.
Just been plastered throughout and some type of rewire i think, the house is going through a sale and was requested by buyers solicitor.
I was going to replace cu and put sockets on three seperate 20amp mcbs voltage drop not a problem as house is tiny.
Any problems cAn you see

A3 Radial 50m2 floor area, 20amp cb 2.5mm2 page 174 OSG

 

[Engineer54]

What about the 268 ohm Ra of the so called TT system earth, ....are you just intending to leave it at that existing value. Now what's the betting that the single electrode is a short thin twig that's of no use to man nor beast!! (except maybe as a test spike for an earth tester maybe!!) What's the Zs value with all bonding in place (if any)??

 

[thekingiam]

Yeah read page 174 earlier, rod is stuck out of ground about 500mm so was going to wack it in and pee on it its on a main road though so i got to be carefullirate:irate:irate:irate:irate:

 

[telectrix]

dok it in. replace with a decent screwed together sectioned rod. n't whac

 

[Welchyboy1]

Nothing wrong with a 20a radial

Ive never understood why loaded consumer units are always stocked with 16a mcbs rather than 20a

 

[Guest55]

i wouldnt be leaving the Ra reading at over 250 , new cu or not.

 

[davesparks]

What about the 268 ohm Ra of the so called TT system earth, ....are you just intending to leave it at that existing value. Now what's the betting that the single electrode is a short thin twig that's of no use to man nor beast!! (except maybe as a test spike for an earth tester maybe!!) What's the Zs value with all bonding in place (if any)??

Funnily enough I've got 2 which I use for that exact purpose, test spikes for earth rod testing.

They also come out for small temporary generator jobs, when the ground is waterlogged and they're only running for 6hours max then they are fine

 

[Octopus]

Out of interest how did you code your finding?

 

[PEG]

Yeah read page 174 earlier, rod is stuck out of ground about 500mm so was going to wack it in and pee on it its on a main road though so i got to be carefullirate:irate:irate:irate:irate:

500 mm? Lovely,simply tap in,25mm at a time,until Ra = 199,place garden gnome over projecting rod,retire for bourbons.:icon12:

 

[Rockingit]

You'll probably discover that the reason it's 500mm proud is because there's a big rock under it!!!!

 

[telectrix]

that's why we have 40" masonry drills. alternatively, the drains may be under it. bang it in and keep it nice and wet.

 

[Deleted member 9648]

Have you checked whether PME is available?

 

[telectrix]

getting technical now. from big hammers to pme.

 

[Deleted member 9648]

I'd Scrub the TT for a PME/TNCS any day if at all possible.