What's the maximum number of downlights/bulbs

[Shafty-Bobs]

A bit of advise please...
I'm wanting to install lots of downlights and wall lights (Mains mainly, but a few low voltage) in the house and I'd like to know if there is a limit so that that I don't go over board. If my MCB has 6A rating and 1.00mm T&E is used for the lighting circuit what is the maximum wattage of bulbs I can use? Can I use say, 50 bulbs at 50W each (2500 Watts)???

 

[andy]

A bit of advise please...
I'm wanting to install lots of downlights and wall lights (Mains mainly, but a few low voltage) in the house and I'd like to know if there is a limit so that that I don't go over board. If my MCB has 6A rating and 1.00mm T&E is used for the lighting circuit what is the maximum wattage of bulbs I can use? Can I use say, 50 bulbs at 50W each (2500 Watts)???

230x6=1380W

so no, you cannot put 2.5KW of lighting on

 

[mapj1]

and if you dont want nuiscence tripping, stay below 1000 watts total per 6A breaker. If you have more, then it is better to split the load into 2 circuits fed by different breakers.

 

[Shafty-Bobs]

Thanks guys
What if I change the lighting circuit into the 16A MCB?
Is 1.00mm T&E still ok?

 

[andy]

Thanks guys
What if I change the lighting circuit into the 16A MCB?
Is 1.00mm T&E still ok?

1mm can carry 15A. so no, you cannot change it to 16A. do as has been suggested and split the circuit. why anyone needs 16A of lighting is beyond me.

 

[Big_Spark]

Shafty...have you any idea of how bright that amount of lighting would be?? Even split amongst all the rooms in the house, that is a shed load of excess lighting, and don't forget, for every 50W halogen, you get about 15W of the energy as light, and about 35W as thermal radiation (heat)

So you would seriously effect the heat balance of the house too.

 

[pdcelec]

Why not fit a couple of 500W halogens in the living room then if the lamp blows it would be a lot cheaper to replace. Sorry cant help myself sometimes

 

[BenStiller]

in OSG your allowed some diversity in a lighting circuit it says 66% not sure if thats for or against though

 

[securespark]

Thanks guys
What if I change the lighting circuit into the 16A MCB?
Is 1.00mm T&E still ok?

1mm can carry 15A. so no, you cannot change it to 16A. do as has been suggested and split the circuit. why anyone needs 16A of lighting is beyond me.

When I did my C & G in the late 80's, we were taught it is possible to wire an immersion heater up to 1mm2 on a 16A circuit in certain circumstances, ie as long as the run is quite short. In practice of course, we use 2.5 minimum, but this was an exercise in theory rather than practice.

 

[mapj1]

yes, but the immersion heater really only draws 12A - being 2.8/3Kw element, and as the only failure is likely total breakdown, rather than a creeping overload, the situation is rather different, as the breaker is only providing short circuit protection.

 

[Shafty-Bobs]

Thanks for all the advise
This is a great site and a big thumbs up for all who contribute to it
I'm so glad I went on this site first and didn't just wire in all the lights. Looks like I need to add another lighting circuit for the kitchen alone. The thing is I only have a 16A spare MCB as all the 6As are used-up so I think this means I need to use 1.5mm T&E

 

[breezer]

get a smaller mcb?

 

[plugwash]

whilst using a 16A breaker for lights is not strictly prohibited i certainly wouldn't consider it advisible.

if you can't get a suitable replacement breaker you could always use a FCU as soon as the cable leaves the CU

 

[Shafty-Bobs]

What about if I change the 6A fuse into a 10A ? Will 1.00mm T&E be ok to light 50 x 50W bulbs?

 

[andy]

What about if I change the 6A fuse into a 10A ? Will 1.00mm T&E be ok to light 50 x 50W bulbs?

2500W is 10.86A, altho i doubt all will be on at the same time, so in theory you could