Lighting electrics- what's going on here?

[Puggit]

Another leftover from the house we've moved in to. I've removed the fitting from theach ceiling that contained 4x 28W bulbs and found this...



There are 3 main cables coming in, each with live and neutral. The live cables are on the left. 2 enter the block on one side and one is connected to the other side.

For the neutral cables, 2 go in to the bigger block together. The 3rd neutral cable goes in to the right of the block, with a brown sleeve!?

Inside the unit we have this:



As you'd expect really. One connector is neutral and one is live - feeding off to the 4 bulbs.

I'm confused by the wiring coming out of the ceiling!

[hairyben]

Its not a neutral, its a switched live (3 plate system) and bog standard stuff.

[roofer]

The one with the brown sleeve is the switch line, the rest are the loop for the circuit , no ?

[crmcatee]

Nothing wrong with that.

The two browns that are joined together are taking the live feed down to the switch.

The blue that's got the brown sleeve is the switched live back to the fitting.



Does make me worried when folks are changing fittings and simple things like this are confusing for them. Makes you understand why Part P came in.

[dav123a]

Does part p even cover work like this ?

[Puggit]

Every other wiring I've ever changed just had 3 wires: blue, brown and green/yellow - hence my question.

[crmcatee]

dav123a said:

Does part p even cover work like this ?

No it doesn't but you can still see the logic for their choice of implementing it.

[Magic919]

People have been confused by these for decades. I doubt such people will have heard of Part P or anything like it.

[dav123a]

crmcatee said:

No it doesn't but you can still see the logic for their choice of implementing it.

I can't it's a nonsense that does little. If you are going to bring something in do it right. That said iirc Prescott help bring it in so that says everything.

[W12GT]

Thing got interesting when we moved into a house we are about to start demolishing. I changed a broken ceiling rose and had a massive firework display! Idiot who installed the wiring has done it with switche neutrals. Damn dangerous!

[hairyben]

W12GT said:

Thing got interesting when we moved into a house we are about to start demolishing. I changed a broken ceiling rose and had a massive firework display! Idiot who installed the wiring has done it with switche neutrals. Damn dangerous!

Erm, you know ceiling roses normally have a permanent live connection regardless of switch on or off?

[Laplace]

W12GT said:

Thing got interesting when we moved into a house we are about to start demolishing. I changed a broken ceiling rose and had a massive firework display! Idiot who installed the wiring has done it with switche neutrals. Damn dangerous!

So, you worked on a circuit without checking if it was dead and the other guy is the idiot? Riiiiiight.

Anyway, as already mentioned it is perfectly normal to have loop in permanent live feeds at a ceiling rose.

[crmcatee]

W12GT said:

Idiot who installed the wiring has done it with switche neutrals. Damn dangerous!

A perfect reason why Part P is a good thing.

[W12GT]

Laplace said:

W12GT said:

Thing got interesting when we moved into a house we are about to start demolishing. I changed a broken ceiling rose and had a massive firework display! Idiot who installed the wiring has done it with switche neutrals. Damn dangerous!

So, you worked on a circuit without checking if it was dead and the other guy is the idiot? Riiiiiight.

Anyway, as already mentioned it is perfectly normal to have loop in permanent live feeds at a ceiling rose.

The circuit was isolated. Things went wrong after putting it all back together and turning back on again. Everything looked OK and had gone back together the way it should - but all was not as it seemed hence pop when I turned it back on.

Note to some others comments - I had part P (don't need it anymore) and am 7671 17th ed qualified.

[Fore Left]

From here.

[W12GT]

Laplace said:

So, you worked on a circuit without checking if it was dead and the other guy is the idiot? Riiiiiight.

Anyway, as already mentioned it is perfectly normal to have loop in permanent live feeds at a ceiling rose.

No and no. Permanent live feed is old fashioned practice - it's dangerous hence not approved anymore:- the main reason being you are exposed to potential shock eveyrine you change a bulb regardless of switch position and before you state turning breaker off before bulb change - good practice yes but not many people do it!

[PoleDriver]

Fore Left said:

From here.

Yep, perfectly standard! And before that it was the same only with red/black instead of brown/blue.

[W12GT]

PoleDriver said:

Fore Left said:

From here.

Yep, perfectly standard! And before that it was the same only with red/black instead of brown/blue.

Spot on.

[Sheepshanks]

Puggit said:

Every other wiring I've ever changed just had 3 wires: blue, brown and green/yellow - hence my question.

The switched live being sleeved makes it easy. I've changed light fittings in various houses (usually red & black wiring colours) and I don't think I've ever seen the switched live marked in any way.

[Jonesy23]

crmcatee said:

A perfect reason why Part P is a good thing.

It's a stupid thing aimed mostly at generating cash for people like NICEIC.

Bodgers just ignore it.

Electricians jump through the right hoops and then get away with installing all sorts of non conforming crap under self certification.

Individuals even with the right qualifications have no obvious route to self certification in a personal capacity and getting someone else to sign off an install under a non self certification route is effectively impossible.

It's one of the biggest loads of garbage ever created matched only by the other similar bits of building control.