16A Lighting Circuits

[Seb101]

The house we bought has 3 lighting circuits with 16A MCBs, most of the loops are done with 2.5mm T+E but I’ve discovered as we’ve been decorating that a lot of the spurs, drops and internal fixture wiring is either 1.5mm or 1mm flex/T&E. This is inherently unsafe right?

The consumer unit is fairly modern, with RCDs and MCBs. A complete re-wire is out of the question right now due to cost, would an interim solution to replace the 16A MCBs with 6A MCBs be a good idea to make these circuits safer?

I‘ve done an audit on the circuits, with the LED bulbs we have fitted everywhere I doubt there is more than 0.5A of demand on any of the individual lighting circuits.

Cheers,
Seb

 

[EFLImpudence]

Very odd.

Yes, replacing the MCBs with 6A will set your mind at rest.

1mm² T&E is good for 16A (1mm² flex not quite) although, as you point out, none will have more than 0.5A to contend with.

 

[Seb101]

Cheers.

Very odd = amateur job. We discovered from a neighbour a few doors down after we moved in that our previous owner did most of the work converting the 1880s building by himself. When it was sold to us they played the old-lady card, she “couldn’t remember“ who did the work as it was so long ago and her husband handled all that sort of stuff. Turns out he did the whole lot himself, and it shows.

 

[JohnW2]

I‘ve done an audit on the circuits, with the LED bulbs we have fitted everywhere I doubt there is more than 0.5A of demand on any of the individual lighting circuits.

Probably less than lat. I doubt that many people would have as much as 115 W worth of LEDs on at once.

I agree with EFLI.

Kind Regards, John

 

[ericmark]

In real terms the wiring is likely OK with 16 amp MCB's, but in theory a standard B22d lamp holder is rated 2 amp, and a ceiling rose 5 or 6 amp, there should be in every bulb a built in fuse so if when the bulb blows you get ionisation (a flash when it blows) the fuse will rupture so rest of lights stay on.

However on the move to energy saving bulbs the fuses seem to have gone, I did have one Ikea bulb blow on a 16 amp circuit and weld the bulb contacts to the holder, no harm done, but resulted in needing to change whole lamp, with this in mind I try to stick to 6 amp for lighting, not for safety as safe enough, but so bulbs will not weld themselves should they fail closed circuit.

That was an old CFL, I think the way LED bulbs are made it is very unlikely there would be a problem with contacts welding when they fail, so changing to 6 amp would be low on the list of things to do, but agree with @EFLImpudence and @JohnW2 for piece of mind change to 6 amp, but would be in no hurry to do it.

 

[Risteard]

A lampholder is suitable for connection to a 16A circuit, unconventional though it is.

 

[conny]

He probably did the loops in 2.5mm because he was using it for the sockets at the same time. Then switched to 1.5 for the switch drops as it is easier to get them in rather than another 2.5mm
By all means drop the MCB to 6A Perfectly safe.