Will 9 Downlights Overload the circuit?

[enigmatic]

Hi apologies if this has been posted elsewhere previously (did a search no results)

Im a novice DIY'er and i've recently purchased 9 240v 50w (max) downlights

im just wondering that being 450w if i installed the max rated bulbs, would the exsisting main be able to handle this load?

also how would i go about checking this load? i believe the wiring in the house could be oldish. there is a new consumer unit with RCBs but i would not know if they updated the wiring also.

any ideas or best to get a qualified electrican?

 

[fattony]

Need a little more info like what size MCB is protecting the circuit, how many lights are already on the circuit (count the light bulbs) and I believe downlights come under Part P - but not 100% certain.

A simple formula for calculating the load is:

Power (Watts) / Voltage = Amps

So your 450watts for the downlighters is approx 2Amp.

1) First determine what size the MCB is, 5,6 or 10Amp
2) Determine how many light bulbs are on this circuit
3) Calculate the load of the circuit using the formula

When counting the number of bulbs allow 100w per bulb unless your counting downlighters then allow 50w.

 

[enigmatic]

i believe the MCB to be a 10amp breaker off the top of my head.
there are 3 lightbulbs upstairs, 3 downstairs i've been lead to believe lighting circuits will have 1200w max, is this right?

thanks for your response i look forward to more info

thanks

 

[fattony]

A 10Amp MCB is the same as 2330 watts, normally you have 2 lighting circuits one for upstairs and one for downstairs and I believe down lighters come under part p. To answer your question you wont overload the circuit with these new lights.

 

[enigmatic]

cheers buddy that helps a lot, i'll have a good bash at it this weekend.

sorry to be a pest but the lights i've purchased are the type with a black cap with terminals inside for the live and neutrel feeds, which type of wire should i purchase will 1.5 twin and earth suffice?

many thanks for your help once again

 

[ban-all-sheds]

I believe down lighters come under part p.

1) Part P of the Building Regulations applies to all work on low voltage or extra-low voltage fixed electrical cables or fixed electrical equipment located on the consumer's side of the electricity supply meter in dwellings.

2) Not all work is notifiable, and installing downlighters is not, provided they are not in a kitchen or special location and if ELV they a pre-assembled lighting set bearing the CE marking referred to in regulation 9 of the Electrical Equipment (Safety) Regulations 1994.

Also, of course, Part B will apply, so if the ceiling into which they are fitted is a barrier between fire compartments then the fire rating will have to be restored.