How many lights allowed on a lighting circuit ?

[gavioli]

Hello,

I am just wondering what the correct legislation/requirment is with regard to how many lights are allowed on a lighting circuit ?

Does diversity apply ? In other words is it perfectly legal to have more current draw than the fuse /mcb fitted if every light was on at one time, or can you allow that not all lights would be on at any one time ?

My house currently has 14 ordinary bulb lights and 18 halogen downlighters on the downstairs citcuit. If I was to put 100W bulbs in all my normal lights and where halogens are fitted 50w max it would be 2300 Watts = around 10amp. Now the bulbs fitted are not 100watt or 50watt halogens - in fact working out the actually wattage that is fitted (some 25w, some 40w, some 60w & 35 W halogens), with all lights on only draws around 4.5 amps

Can anyone tell me if, probably on inpection if I sell the house, this would be picked up as an overloaded circuit ?

Thanks.
Nick.

 

[plugwash]

the diversity guidelines for lighting cuircuits say you should allow a minimum of 100W per point and more if higher rated lights are actually fitted.

but the diversity guidelines are just guidelines not rules set in stone.

if a convininat time crops up then the cuircuit should be split but there is nothing urgently wrong.

 

[Albert]

I am just wondering what the correct legislation/requirment is with regard to how many lights are allowed on a lighting circuit ?

the limit of lights depends on the current capacity of the wire.

Does diversity apply ? In other words is it perfectly legal to have more current draw than the fuse /mcb fitted if every light was on at one time, or can you allow that not all lights would be on at any one time ?

On it's face what you are saying makes sense, but, think that you can't predict what the next occupier will use as lights, if the circuit will be overloaded it might cause fire (not good), the other thing is that the only factor that the mcb's value is based on is the wires current carrying capacity (which the calculation requires different factors to consider). the mcb exists to protect the wire, if the mcb has the correct value it will trip before any damage is done to the wire, in that case if the circuit is overloaded the mcb will trip.
Normally as a fast rule you can consider for a circuit a load of 12 bulbs of 100watt which will demand 1200Watt, this will require a mcb of 1200/230=5.22A, meaning mcb of 6A which as you know used as the default mcb for lights.

 

[gavioli]

Thanks guys for your comments.

I think it will be worth while splitting later on, although having recently decorated and knowing that the current "current" !! drawn with the bulbs fitted will not exceed the wire capability or fuse, then for now it'll stay as is.

I just wondered with all this new Part P and the home sellers pack coming next year, should I look to sell soon, what a so called surveyor may have said about it !!

Nick.

 

[Albert]

Thanks guys for your comments.
I just wondered with all this new Part P and the home sellers pack coming next year, should I look to sell soon, what a so called surveyor may have said about it !!Nick.

1) Part P is in force since 1 January 2005.
2) selling soon or late will not make any defference, the elctrics work in the house need to be certified. In part P section 0 Notification at work subsection 0.8 subsubsection 'b' subsubsub ii) says it. You can get a free copy from the internet, read it.

 

[Albert]

ignor