Downlights tripping electric

[mackroyd]

So, I'm doing a significant garden redesign project and trying to do as much of the work as possible. Part of the project is a summerhouse/shed combo building at the bottom of the garden. I've had an armoured cable run from the house consumer unit to the shed area of the building, into a small consumer unit. From the 6amp MCB in the consumer unit I've run cable to four, four terminal connector boxes. One for a shed bulb, one for some outside under soffit leds, and two for lights in the summerhouse. The outside leds and two summerhouse light switches are all into one four light switch unit. Initially I just wired the two summerhouse lights up to single lamps, but the intention was always to replace these with 7 downlights on each. So up until installing the downlights all worked fine, light switches in the shed, summerhouse and those for the soffit lights functioning perfectly. So I come to install the downlights just replacing the normal (previously working light) with a downlight then linking an additional 6 (typical 50w GU10 halogen bulbs). Did this to both lights, so now two light switches each controlling 7 downlights.
Power back on tried one switch and only the first two downlights lit up. Tried the other switch and it would switch like something might have got inside it and be blocking it from switching. Then the 6 amp MCB tripped? I took apart the light switch just to see if it was debris in it preventing it from switching, I didn't notice any but when I put it back together it was switching fine. So flicked the MCB back, tried out the shed light (fine), outside soffit switch (fine) but any of the two summerhouse downlights just tripped the electric again. I've popped all the downlights out and checked all the connections and all seem sound.
My next idea is to drop down the ceiling plasterboard over the two four terminal connector boxes to check I haven't disturbed anything here (the two for the summerhouse downlights causing the problem are the last two in the chain) when I was putting in the ceiling insulation and fitting the ceiling plasterboard. Before I do however I'd really welcome any advice on whether there should be something else I should be checking. Thanks in advance...

 

[Richard Burns]

If your 6A MCB is tripping then you almost certainly have a short circuit some where from the switched line of the summer house lights to earth or to neutral.
You should try and arrange the junction boxes so that they are not inaccessible behind a plasterboard ceiling as this will make maintenance much easier (and be compliant with the regulations).

If you turn off the circuit and disconnect it and then test continuity from the switched line of the summer house lights to N and E at various points along the new downlights you should be able to narrow down where the fault is located.

 

[Pete999]

If your 6A MCB is tripping then you almost certainly have a short circuit some where from the switched line of the summer house lights to earth or to neutral.
You should try and arrange the junction boxes so that they are not inaccessible behind a plasterboard ceiling as this will make maintenance much easier (and be compliant with the regulations).

If you turn off the circuit and disconnect it and then test continuity from the switched line of the summer house lights to N and E at various points along the new downlights you should be able to narrow down where the fault is located.

Better still get a Electrician in to sort this mess out.

 

[telectrix]

it's also possible that the MCB is tripping due to LED inrush current. either way, you need an electrician to advise and/or sort this problem. stockport happens to be on the edge of my operating area, so i could help, or someone closer can.

 

[Octopus]

So, I'm doing a significant garden redesign project and trying to do as much of the work as possible. Part of the project is a summerhouse/shed combo building at the bottom of the garden. I've had an armoured cable run from the house consumer unit to the shed area of the building, into a small consumer unit. From the 6amp MCB in the consumer unit I've run cable to four, four terminal connector boxes. One for a shed bulb, one for some outside under soffit leds, and two for lights in the summerhouse. The outside leds and two summerhouse light switches are all into one four light switch unit. Initially I just wired the two summerhouse lights up to single lamps, but the intention was always to replace these with 7 downlights on each. So up until installing the downlights all worked fine, light switches in the shed, summerhouse and those for the soffit lights functioning perfectly. So I come to install the downlights just replacing the normal (previously working light) with a downlight then linking an additional 6 (typical 50w GU10 halogen bulbs). Did this to both lights, so now two light switches each controlling 7 downlights.
Power back on tried one switch and only the first two downlights lit up. Tried the other switch and it would switch like something might have got inside it and be blocking it from switching. Then the 6 amp MCB tripped? I took apart the light switch just to see if it was debris in it preventing it from switching, I didn't notice any but when I put it back together it was switching fine. So flicked the MCB back, tried out the shed light (fine), outside soffit switch (fine) but any of the two summerhouse downlights just tripped the electric again. I've popped all the downlights out and checked all the connections and all seem sound.
My next idea is to drop down the ceiling plasterboard over the two four terminal connector boxes to check I haven't disturbed anything here (the two for the summerhouse downlights causing the problem are the last two in the chain) when I was putting in the ceiling insulation and fitting the ceiling plasterboard. Before I do however I'd really welcome any advice on whether there should be something else I should be checking. Thanks in advance...

HUM...... not the correct box to be concealed and inaccessible...