DIY Doctor UK DIY Forums

Hello. I hope you can give me the advice i need.

I have installed a new light circuit in a garage and i have a problem. The garage has its own consumer unit which has a socket ring attached. It also has a 6A circuit breaker to which i have installed the new lights.

The strip lights have a 3 chock block for wiring (L N E).
When i switch on, they trip. I have obviously wired the switch to the light incorrectly. I believe the switch is wired correctly :


Here is a diagram of how ive wired it all.

Other lights ive installed have had 4 or more chocks so a Sw Live can be installed. These lights only have chocks with 3.

Thanks in advance. Danny.

Nice diagram. Pity more folk do not do that when asking questions like yours, it makes life much easier.

If you look at your diagram you will see that the switch is connected directly across live and neutral, when you operate the switch you are putting a dead short across the supply, this is why your MCB trips (it is supposed to)

This is where I have to admit envy of your diagram, I do not have the facility to draw like you.

The light with 3 cables.
The live (red) from the consumers unit, should be connected directly to the live (brown) that goes to the switch. (You will need a single connector block for this.)

The switched live (Blue) from the switch should connect to the L in the lamp NOT the N (where it is now) It should also be marked at both ends with brown sleeving to indicate it is live.

The wires from the first light to the second light stay where they are.

If you post another drawing as I have said, I will check it is right for you.

Thanks for your helpful reply Mr White. Here is the amended diagram and i hope ive understood you correctly.


Thanks again.

As I said before, I like your drawings.
You can now see that when the switch is off live comes from the supply, and goes no where. (as the switch is in the off position) But when the switch is turned on live then goes to the first and second lights, not as you had it, from live to neutral.

Yes your drawing is now correct.

Thanks Mr White.
All is now well and we have light.

Can I ask one more.
My mum wants a new security light fitted. No switch will be needed as it will work via pir only.
The wiring installed is Twin&Earth.
But the security light she has bought has a four connector block in it. Can you advise the wiring pattern needed. Thanks.

I can guess, but before I do, what do the instructions say?

The diagram appears to conflict with the markings in the moulding.

I would connect (As I first thought) to L N & E
The L with an arrow is an over ride. (But it says that if you read the instructions)

Thanks very much