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[gaspode 0]

Have an odd electrical issue at home and wondered if anyone could point me in the right direction..

SOME of my downstairs lights have stopped working, all seems fine in the CU - nothing's tripped. When I take one of the (non-working light) switches off the wall and test the voltage, it does register something but is usually less than 20V..

This seems odd, I'd have imagined it would either work or not work, not be weirdly under-voltaged.. Not sure where to begin trying to diagnose what's going on..

Any pointers?

[-AJ + 102]

Have an odd electrical issue at home and wondered if anyone could point me in the right direction..

SOME of my downstairs lights have stopped working, all seems fine in the CU - nothing's tripped. When I take one of the (non-working light) switches off the wall and test the voltage, it does register something but is usually less than 20V..

This seems odd, I'd have imagined it would either work or not work, not be weirdly under-voltaged.. Not sure where to begin trying to diagnose what's going on..

Any pointers?

When you are measuring at the switch, where are you measuring between, because the two wires in the switch are both live... Supply and Switched - the neutral is up in the light fitting or junction box depending on the wiring system used - When you are measuring, have you also got the multimeter set to AC and not DC..common mistake I see!

[callsign-kid 1,617]

If its some of the lights then you have two different lighting circuits.

[gaspode 0]

Yep, multimeter was set to AC and I was measuring across the switch. On the working lights, I was seeing a 220v difference across the switch, less for the non-working ones.

I have, since the original post, found the issue...

A few months ago, I replaced the old light in the kitchen with a new one. When I did this, I discovered there were three sets of cables all connected into the same ceiling rose. The new light had a chocolate-block inside the ceiling rose part so I connected the wires into that. It seems I didn't do a very good job at it and, for some reason, one of the wires eventually popped out..

Looks like a trip to Homebase tomorrow to get a junction box and then some time lifting the floorboards in the batchroom so that I can link the three wires in the gap above the ceiling and only have the one cable running to the light fitting..

If its some of the lights then you have two different lighting circuits.

It would appear not, there's only one circuit for the downstairs lights at the CU. Seems several of the downstairs lights are spurred off the kitchen light

[Sceptre + 2,701]

Have you considered calling a proper electrician? DIY electricity bodging can knock quite a bit off the value of your home.

[gaspode 0]

Am competent enough to sort it, just need to spend the time doing it properly instead of bodging it like I did when I replaced the fitting..

[oddbod 393]

If its some of the lights then you have two different lighting circuits.

As I remember it light circuits are series.

The power originates from the consumer unit and each light fitiing has a 'loop in/loop out' providing the juice for the switch pair/lamp.

The last fitting on the circuit has no loop out; a break anywhere on the circuit will take out all of the fittings after the break in the circuit.

[Administrative Account 7]

This thread reminds me of the chap who kept on bringing random parts of his TV into my shop and asking me to test them (I kept on saying no because I was concerned for his safety)

I have not seen him since...

[gaspode 0]

This thread reminds me of the chap who kept on bringing random parts of his TV into my shop and asking me to test them (I kept on saying no because I was concerned for his safety)

I have not seen him since...

This big red wire labelled "HT"... what's this do, then?

[Soapyw 38]

May be worth asking a proper electrician about this. The reason your control wires are all usually in the light fitting is its enclosed and close to an earth. Having random junctions under your floor boards with live loop cables isn't a great idea. I'm not an electrician, more electronics but I watched our house have a full rewire recently and have been messing with plenty of lights. I wouldn't join a loop at random points.

[Administrative Account 7]

I often have customers asking if I stock earthing rods for their antennas.

So I ask them if their electricity supply is PME (Protective Multiple Earthing)

I can hear their eyes glazing over via the phone and they say "What?"

So my reply is always "Sorry, out of stock"

[gaspode 0]

May be worth asking a proper electrician about this. The reason your control wires are all usually in the light fitting is its enclosed and close to an earth. Having random junctions under your floor boards with live loop cables isn't a great idea. I'm not an electrician, more electronics but I watched our house have a full rewire recently and have been messing with plenty of lights. I wouldn't join a loop at random points.

The junction was there anyway, all I've effectively done is to lengthen the connection between the junction and the light fitting. I'm not joining a loop..

It's a 50s house which looks like it's had its wiring re-done at some point as there's still lengths of very old (but unused) cables visible in some places. Some parts of the lighting circuits have been extended (to provide lighting in an extension, etc) and it's this organic growth that seems to have lead to some odd setups. The kitchen light fitting, it seems, used to be a bit of a junction so I've now rationalised it somewhat.

[Soapyw 38]

Fair enough. My house is 50's, our rewire was its first I think! The sparky's were taking pictures of some junctions as they couldn't believe the number of wires going in, and at least one light fitting surround was live!! Sounds like we may have bought from one of your would be customers Rocket!

[P3DRO + 400]

I often have customers asking if I stock earthing rods for their antennas.

So I ask them if their electricity supply is PME (Protective Multiple Earthing)

I can hear their eyes glazing over via the phone and they say "What?"

So my reply is always "Sorry, out of stock"

You should ask if the earthing system is TT, TN-S or TN-C-S and see who will faint..

(p.s. a TT system has an Earth rod at the installation, a Tn-s has a seperate earth running back to the star point of the supply transformer and a TN-C-S has a seperate Earth up to the Consumer unit and around the house but then joins the Neutral back to the Supply Transformer before your consumer unit)

Similarly Gaspode, My dad's neighbour tried doing a rewire and did an OK job i suppose...but....out of 4 lights only 2 would work when 'ON' then when you turned the switch off the other 2 come 'ON' and the original 2 went 'OFF'. I HIGHLY RECOMMEND Putting an electrical tape flag around the supply cables you are dealing with or things can get very confusing. You will save yourself loads of time if you identify and flag all the cables first.