Fuse Blown due to Kitchen Spotlights

[guygb1]

I have 6 LED lights in the Kitchen all connected with separate transformers.

One of the lights was flickering intermittently so I decided to switch the light for a GU10 LED light. I removed the transformer and fitted the new light.

The kitchen lights initially worked and then after a time the fuse blew.

It appears that the fuse only blows when the kitchen lights are switched on and then only after about 30 seconds, not immediately.

I checked the light fitting thinking it could be a short circuit but it all seems fine. I have changed the fitting nonetheless and the problem still occurs. I have also removed the light fitting completely and isolated the live and neutral wires but the fuse still blows. Finally, I replaced the old fitting and transformer and still the fuse blows after the kitchen lights are switched on.

When I checked the connections for the light fitting I noticed that the earth wire was slightly loose and so I tightened this up. There was also some bare earth wire which I have covered with tape.

I am now wondering if the light switch got damaged due to the change in voltage of the lights, which is causing the fuse to blow.

Otherwise, I am at a loss to work out what the problem is and would appreciate any help please.

 

[JohnD]

where is the fuse that blows?

 

[guygb1]

The fuse for all the downstairs lights blows, which is in the main fuse box. It is a flip switch so the switch flips down when the fuse blows and I have to flip it back up again to get the lights working.

 

[EFLImpudence]

What you describe suggests an overload.

This is not likely on a lighting circuit that has been working satisfactorily.

I would guess that one (or more) of the other transformers is failing.

 

[guygb1]

Thanks for your response. So are you suggesting that it is a coincidence that the problem occurred after I changed the fitting or could this have caused one of the other transformers to become faulty?

Also all the lights seem to be working still if only for a half a minute or so until the fuse blows!

 

[EFLImpudence]

So are you suggesting that it is a coincidence that the problem occurred after I changed the fitting

Yes. Nothing you have done could cause an overload which would take thirty seconds to blow the fuse.
A short circuit, which you mentioned, would blow it instantly.

or could this have caused one of the other transformers to become faulty?

I wouldn't think so other than I presume they are all the same age.

Also all the lights seem to be working still if only for a half a minute or so until the fuse blows!

And then they don't.

 

[guygb1]

OK. Thanks.

I shall check the transformers when I get home tonight. Will it be obvious by inspecting them to check which one/s are failing?

All the transformers are fairly new - fitted within the last year.

 

[EFLImpudence]

Will it be obvious by inspecting them to check which one/s are failing?

Probably not but one may feel warmer then the others.

All the transformers are fairly new - fitted within the last year.

Not long.


Just to be sure -

It is definitely a fuse or MCB which is 'blowing' and not an RCCB or RCBO.
RCCBs and RCBOs have a test button on them.

 

[guygb1]

Definitely MCB

Is there a quicker way of testing each transformer rather than replacing them one by one?

 

[westie101]

Disco0nnect them one by one. at some point, if it is one of them, the MCB will stay closed! You can always check again by re-connecting the suspect one which should trip the MCB

 

[guygb1]

I took all the bulbs out and hung the wires down and this seems to have resolved the problem!

If one of the transformers is failing then I suspect I shall need to wait until it actually fails before changing it. For the moment all is working well!

thanks to everyone for your assistance and comments

 

[Iggifer]

I took all the bulbs out and hung the wires down and this seems to have resolved the problem!

If one of the transformers is failing then I suspect I shall need to wait until it actually fails before changing it. For the moment all is working well!

thanks to everyone for your assistance and comments

Sounds like you have a short on one of them then if simply moving the cables has solved it.

Check all the cables you can see for damage / signs of overheating.

You still have the bulbs in?