Garage strip light trip

[TrotterD]

Hello, hope you are well.

I have moved to a new house just under a year ago and seem to have developed a problem with my Garage Lights.

There was two big long strip lights controlled by a single switch. A couple of few weeks ago, one of the strip lights blew a fuse and stopped working. I replaced the fuse but noted that the plastic was very brittle and a bit chard.

Just the other day the same light blew again, so I thought I would replace them both with newer, but smaller strip lights. This seemed straight forward and all worked fine. I also replaced the light switch because it looked old and squeaked as you push the switch in.

Just today the RCD on the board tripped as I turned the lights off in the garage. The new lights don't have fuses so I guess that's why the RCD tripped. The light circuit is not on the RCD protection, just the sockets, shower and EVC Point.

So I looked at what I thought was the junction box that the two strip light wires come from and it appears to actually be a ceiling rose. One of those white circular things you normally see a single light bulb dangling from. It had tape on and was broken slightly.

Now with the two strip lights connected to it, if I flick the light switch on and off about three times, the RCD trips. I have removed one strip light and cannot get it to trip by doing the same tests.

Could this problem be the lack of a proper junction box and the old ceiling rose choc blocks are just don't have the correct rating.

Any advise would be appreciated.

Untitled

• TrotterD
• 16 Oct 2014
• 1

Regards

Dave

 

[EFLImpudence]

Without delving too deeply, we have come across things like this before where there seems to be nothing wrong but it just happens.

Tidy it up and then - Try a new switch.

 

[TrotterD]

Hello EFLImpudence, hope you are well.

Ok, I will fit a proper junction box tonight and see if that fixes the problem.

Thanks for the reply.

Regards,

Dave

 

[EFLImpudence]

Thank you.

The tidying up was just a general comment.

It sometimes switches that do funny things to RCDs. Try a new one.

 

[TrotterD]

Hello, yeah I put a new switch on the same time I put the new strip lights up. The old switch didn't look and feel very nice. But I still have the problem. I will put a junction box on and hope that fixes it.

Thanks

Dave

 

[EFLImpudence]

Oh. that's not it then.

Well maybe there is something wrong - see how it goes.

 

[TrotterD]

Hello,

Ok installed a 20amp 4 terminal junction box in place of the ceiling rose block and it still trips. Back to one strip light now. Will call an electrician in the morning to take a look at it.

I suspect it should be wired completely different and maybe just been a matter of time when it was going to start tripping.

Thanks

Dave

 

[TrotterD]

Hello, just an update if anybody was interested.

After installing a proper 20A 4 terminal junction box secured to the ceiling joist, I decided to change the way the two strip lights were wired to it. The original setup was that both strip light were wired direct to the ceiling rose. This seemed like a lot of wire to stuff into the junction box so decided to wire just one strip light to it and then daisy chain that strip light to the next one.

I still could make the RCD trip after doing this. But while wiring it up it didn't feel right that the Earth cable from the lights were connecting to the Neutral on the ceiling rose and the Neutral from the lights connecting to the Earth on the Ceiling Rose.

You can see this in my photo of the original wiring in my original post.

So I did a bit of research on the Information Superhighway and was convinced that this configuration was wrong and needed to be swapped around. So I swapped them so Earth from the light went to Earth on the ceiling and Neutral from the light went to Neutral on the ceiling. This makes more sense to me.

All seems well and I can't trip the RCD as yet.

I don't know what the danger of the original configuration would have meant, I am guessing that if the light were on then the metal housing of the lights could have been live.

Anyway, I think I will still get an electrician around to check it.

Regards,

Dave

 

[AndyPRK]

Thanks for the update.

 

[EFLImpudence]

Yes, thanks for update.

As it was only an intermittent fault I didn't really look at the picture but, now you mention it, the single cable nearest the camera connected to the block looks to be all wrong.
I presume this is the cable to the other light.

As this was only intermittently tripping the RCD, is it possible that the RCD is faulty?

 

[TrotterD]

Hi EFLImpudence, hope you are well.

No, on the picture, the cable nearest the camera is the switch cable, I didn't change this one. On that photo I had removed the secondary light from the equation, you can see it dangling in the background.

Here is a better picture of what was wired:-

Untitled

• TrotterD
• 17 Oct 2014
• 1

So the three wires to the right of the image are coming from one light. The three wires in the background are from the light I disconnected. As you can see the wires on the right are mixed up. I am sure the Earth wire should be connecting to Earth and Black to Black.

So I swapped them and have not had the fault again.

I would like to know what danger this mix-up could have caused.

Regards,

Dave

 

[EFLImpudence]

Well, unless the switch was similarly wired wrongly I can't see how it would have worked at all.
I am a bit confused.
It would seem the RCD should have tripped all the time.

What are the three cables which are connected on the left?

One must be the supply.
Does the supply go on to somewhere else?
Is there another light somewhere?

 

[TrotterD]

Well. I am sure the wire with the yellow sticky tape round it goes to the switch. The other wires I thing are part of the lighting circuit for the down stairs. There is out door lights and a single pendulum light in the garage loft. Both on sepertate switches.

Regards

Dave

 

[ban-all-sheds]

There is ... a single pendulum light in the garage loft.

Do you have swinger parties up there?

 

[TrotterD]

There is ... a single pendulum light in the garage loft.

Do you have swinger parties up there?

Are you asking cos your into it or because those type of light bulbs are the right type in the swinging circle.