Electrical help please!

Adam_151 · 12 Feb 2011 at 19:12

MrCake said:
Last question I promise - I take it if I get the L & N mixed up, the light wont work and I just reverse them as I cant see any clear mark on the current holder?

No it will work fine, but depending on what kind of lampholder it has it may be dangerous!

If its a baynout cap or a GU10, dont worry too much, but if its a screw cap then live must go to the centre pin and NOT the outside (we'll ignore the E27 exception)

What sort of lamp does it take and do you own a multimeter?

Dabbles · 12 Feb 2011 at 19:22

I am an electrical engineer and have some advice for you.

Like everything to do with mains electrics, be very careful and if you don't know what you're doing 100%, ask someone who does.

230V can be dangerous. It is quite unlikely to kill if you get a short belt, but if you are sensitive to electric shocks due to underlying medical issues that you might not know about or if you get a prolonged shock (particularly across your heart) then you might be in BIG trouble.

I have to be honest, some of the questions you are asking suggest you don't know enough to be doing this yourself. Sorry if that's not what you wanted to hear, but I'd rather say it than give you advice on how to do it badly and hurt yourself.

MrCake · 12 Feb 2011 at 19:48

Adam_151 said:
No it will work fine, but depending on what kind of lampholder it has it may be dangerous!

If its a baynout cap or a GU10, dont worry too much, but if its a screw cap then live must go to the centre pin and NOT the outside (we'll ignore the E27 exception)

What sort of lamp does it take and do you own a multimeter?

The new light fitting runs a 40W G9 halogen bulb - will this be dangerous if I invert the L & N? I do indeed own a multimeter.

I appreciate the concern Dabbles and do know how dangerous electrics are but will be making sure that the lighting circuit is off and will check this before doing anything. I have changed several light switches and wall sockets but this one threw me as it was not what I expected to see.

SB118 · 12 Feb 2011 at 20:14

Should be safe enough if you swap the wires with a G9, the "live" pins are inside a holder so you won't be sticking your finger in it.

Dabbles · 12 Feb 2011 at 20:16

MrCake said:
The new light fitting runs a 40W G9 halogen bulb - will this be dangerous if I invert the L & N? I do indeed own a multimeter.

I appreciate the concern Dabbles and do know how dangerous electrics are but will be making sure that the lighting circuit is off and will check this before doing anything. I have changed several light switches and wall sockets but this one threw me as it was not what I expected to see.

Yeah, it can confuse having the switched live coming in on a black core. Once you've worked out which is which cable and which core should be doing what you should be ok. It looks like you have a spur feed coming in (which will have the live, neutral and earth coming in to the pendant) and the switch feed going out.

Your post at 18:33 seems to make sense, you *should* check that the supply neutral goes to the N connection on your new light and then put some red tape or similar on the black switched live and connect it to the L connection. All earths should be tied together in the earth connection.

Mixing L & N up will technically work as you are working with AC, but can lead to 'unexpected' conditions, especially when someone accidentally touches a black wire and get a fairly big shock from it!

helpimcrap · 12 Feb 2011 at 20:33

Before you disconnect it leave the electric on and test it using a multimeter. The green = earth, black=neutral, red=live is what it should be. don't take this advice though - consult an electrician if unsure.