Absolutely no earth for lighting circuit.

[Goody]

I have replaced a re-wireable CU with a 6 way single RCD board. The lighting circuit uses a single stranded phase & neutral cables in a metallic conduit and the conduit (supposedly) acts as earth conductor, but although I could see the conduit at the ceiling roses, I couldn’t see the presence of earth.

Sanded down the conduit at the CU, used new earth clamp and tried a wander lead to check earth continuity, but no luck at all. I could tell the landlord that he needs a new circuit for the lights and he would say that he had no mishap whatsoever for the last 20 years. What could be done in this situation?

Any input is much appreciated!

 

[TPES]

I have replaced a re-wireable CU with a 6 way single RCD board. The lighting circuit uses a single stranded phase & neutral cables in a metallic conduit and the conduit (supposedly) acts as earth conductor, but although I could see the conduit at the ceiling roses, I couldn’t see the presence of earth.

Sanded down the conduit at the CU, used new earth clamp and tried a wander lead to check earth continuity, but no luck at all. I could tell the landlord that he needs a new circuit for the lights and he would say that he had no mishap whatsoever for the last 20 years. What could be done in this situation?

Any input is much appreciated!

Ensure every accessory on the lighting circuit is class 2, warning label on the CU to notify that there is no earth to lights.

 

[needasparks]

Normally as long as no class 1 metalic equip and IR within its ok but are you saying there is no earth cont on the tubework ? if so it must be corrected as you cannot fail your own work, can you.
Can you locate the part where the break is ? How easy to just run a cpc through the tube and be done with it.

Edit
Should have asked, is this accessable to touch in a code 2 kind of way ?

 

[TPES]

If I read it right you only changed the CU, not touched the lighting circuit, so you only ensure your CU change is upto scratch.

 

[Octopus]

Ensure every accessory on the lighting circuit is class 2, warning label on the CU to notify that there is no earth to lights.

This is what Elecsa advised me to do recently.

 

[Jay Sparks]

Hi,

In an ideal world, you would run a new cpc to all the lighting points & switches but then again, in an ideal world, I would be a millionaire and married to Mariah Carey, who would also be dynamite in bed!!! But as the guys have said above, make sure no class 1 equipment is connected and a label on the cu stateing that none should be connected in future should be ok.

Jay

 

[JONOXNAM]

I have replaced a re-wireable CU with a 6 way single RCD board. The lighting circuit uses a single stranded phase & neutral cables in a metallic conduit and the conduit (supposedly) acts as earth conductor, but although I could see the conduit at the ceiling roses, I couldn’t see the presence of earth.

Sanded down the conduit at the CU, used new earth clamp and tried a wander lead to check earth continuity, but no luck at all. I could tell the landlord that he needs a new circuit for the lights and he would say that he had no mishap whatsoever for the last 20 years. What could be done in this situation?

Any input is much appreciated!

The electrical safety council have a guidance note on replacing CU for lighting installs with no cpc, guide 1... here a link to it...

Best practice guides : Electrical Safety Council

 

[Goody]

Just smashing feedback from everyone; thank you all for your contribution.

The ceiling is concrete and I can’t possibly trace out where the conduit broke and I am left with only one option and that’s to do as TPES says.

Cheers!

 

[PC Electrics]

I have replaced a re-wireable CU with a 6 way single RCD board.

Any input is much appreciated!

All circuits on one RCD? Surely this doesn't comply with regs??

 

[DurhamSparky]

i was just about to comment on that!! i have been know to install 3-4 circuits on 1 RCD but 6..!! you can get 3x3 split load from MK

 

[Goody]

i was just about to comment on that!! i have been know to install 3-4 circuits on 1 RCD but 6..!! you can get 3x3 split load from MK

I quite agree but this flat has only 3 circuits.

 

[jase]

in that case some would say should fit RCBO's, but as it is i cannot find a reg that dictates the practice of splitting up circuits as to minimise inconvienience, either in the BGB or on site guide, I think it is one of those urban myth "recommendations" that everyone takes as gospel.
would be happy to be proved wrong on this one tho

 

[mogga]

thats where I feel the regs fall down only looks like rcbo each circuit

 

[jase]

must be a reg somewhere, otherwise why did dual split cu's come onto the market after 17th ed?

 

[jase]

must be a reg somewhere, otherwise why did dual split cu's come onto the market after 17th ed?

ahh, seek and you shall find. 314.1 pge 46 BGB. :bulb2: