Dual board with no earth on final circuits

[Sparksaflyin]

Hi guys. Need to change the fuseboard at my parents house but none of their final circuits have a cpc run to them. Obviously have an earth on the main incoming so I can get a 16mm earthing conductor up to my new 18th edition metallic consumer unit but they don’t want a rewire so none of the final circuits will be protected with an earth.

My question is will this be an issue in the functionality of the rcds? Obviously the rcd functions on an imbalance between live and neutral so as far as I’m concerned it shouldn’t be too much of an issue hopefully, just wanted to get some of your opinions on the matter.

Another issue I can see is how I’m supposed to test for disconnection times without an
earth?

Opinions would be greatly appreciated

Thanks

 

[telectrix]

are you sure of the no cpc? maybe on lighting, but all other circuits should have. what's the approx. age of the installation? are the circuits in metal conduit providing the cpc's? need more info. inc. pics.

and you can't possibly go ahead with a CU install without confirming presence of CPC's

 

[westward10]

None of the circuits incorporate a cpc?

 

[mattg4321]

I've never come across a property with no CPC on any circuit!

 

[Resu]

My guess would be conduit

 

[Sparksaflyin]

Appreciate the speedy replies. I’ve not done any in depth research as yet, I just had a quick check of a 2 light switches while I was round there this evening having dinner. I will have to have a more in depth look now. Just thought I’d get some opinions on it before I did. I didn’t look for metal conduit in the back box but that makes perfect sense actually.

 

[Dustydazzler]

Micc ?

 

[mattg4321]

Appreciate the speedy replies. I’ve not done any in depth research as yet, I just had a quick check of a 2 light switches while I was round there this evening having dinner. I will have to have a more in depth look now. Just thought I’d get some opinions on it before I did. I didn’t look for metal conduit in the back box but that makes perfect sense actually.

Just because the lighting circuits (or maybe just the switch drops) don't incorporate a cpc you would assume all circuits don't have one??

 

[Sparksaflyin]

One thing I did notice is there were 3 supply cables coming in but why would this be in a 3 bedroom house? A little over the top don’t you think?

 

[telectrix]

One thing I did notice is there were 3 supply cables coming in but why would this be in a 3 bedroom house? A little over the top don’t you think?

get us some pictures. we love pictures. helps those of us that can't read grown-up writing. .

 

[Sparksaflyin]

Just because the lighting circuits (or maybe just the switch drops) don't incorporate a cpc you would assume all circuits don't have one??

Thanks Matt. Maybe I should have done a bit more digging before posting. I was clearly feeling lazy

 

[telectrix]

Thanks Matt. Maybe I should have done a bit more digging before posting. I was clearly feeling lazy

ytou should be able to get a government job then

 

[Sparksaflyin]

Just because the lighting circuits (or maybe just the switch drops) don't incorporate a cpc you would assume all circuits don't have one??

And if I remember correctly I changed a couple of lights over for them years ago and there was no earth at the ceiling rose either

 

[telectrix]

when was the house built ( approx. ).i'll guess 60's

 

[bigspark17]

Appreciate the speedy replies. I’ve not done any in depth research as yet, I just had a quick check of a 2 light switches while I was round there this evening having dinner. I will have to have a more in depth look now. Just thought I’d get some opinions on it before I did. I didn’t look for metal conduit in the back box but that makes perfect sense actually.

If this is hoe you look into changing a cu, then my advice would be dont!!