10amp ok for lighting ?

[scottg]

i got one lighting circuit protected by 6amp mcb type b that is tripping when all lights are switched i've got allot of down lights and flor fittings
i've had an electrican recommened 10amp could anyone see a disadvantage to this or what would you recommend?
thanks for any feedback

 

[Taylortwocities]

Your electrician friend should have said that you can only change the fuse if the circuit checks out as OK for a larger device.

To do this you would need to check the Earth Loop Fault Impedance and see if its within limits.

To do that you'll need an EFLI tester and a copy of BS7671

Maybe your friend can help you out?

 

[david_uk]

If you have a high inductive load (lots of flourescent fittings) you may need a type C MCB as opposed to a type B. It may be that a 6A mcb is correct for the circuit, but just needs a type C. Need a bit more info I'm afraid. How many fittings on the circuit, wattage, how many fluorescents?

I would not be inclined to simply up the rating of the mcb unless I'd done the maths and they'd checked out.

 

[ban-all-sheds]

Your electrician friend should have said that you can only change the fuse if the circuit checks out as OK for a larger device.

And that you are required to notify your LABC. In advance if the work isn't done by a registered electrician.

 

[sparkiedave]

also, not all light fittings and switches are made to carry 10 amps

 

[ericmark]

Although you can in theory feed lighting with up to a 16 amp overload device this is only if the items already used are rated at 16 amp and most ceiling roses are rated at only 6 amp so to change to a main 10 amp feed would also require fuse connection units to be fitted to supply all items which are not rated at 10 amp or more so in most houses this is not an option.

Unless someone has gone daft and tried to use the lighting to also heat the room for example an array of silly 50 watt spot lights then 6 amp should be ample.

The first action would be to find why more than 6 amp is required. 6 amp will run up to 1380 watt easy enough to add it all up.

If I look at max in my house 6 x 100 living room 2 x 100 dinning room 100 entrance hall 100 each bed room 2 x 60 kitchen (Discharge) 3 x 60 Garage 2 x 60 (Discharge) loft 100 bathroom 100 airing cupboard I can just about get 8 amp but in reality 6 x 22 for living room and 2 x 22 for dinning room with max of 60 watt for any non discharge bulb means even if I leave garage and loft lights on I only just reach the 6 amp limit and this is with both upstairs and down stairs on same MCB so I would say something must be wrong.

 

[david_uk]

It certainly is worth checking that the lighting supply is running just the lighting. Went to a callout recently where the ancient 5a mcb was tripping after 5 minutes. Problem was the fan heater some numpty had attatched to the loo light on the grounds it was the nearest source of power. It's possible that someone has done something similar, and is worth checking for.

 

[viewer]

Following on from last replies; this needs a full check, not just obvious outlets from the lighting circuit. I spent quite a while with a similar set of symptoms, to eventually find that the burglar alarm fitter had joined into the lighting circuit using a surface mounted double 13A socket as a junction box.