Best method of distribution

[jhauxwell]

Hi,


Ok - heres my problem.....

i've got about 48 intelligent light fittings in a club that all need to be powered separately so they can be switched individually. Each fitting is internally fused at 3.15A. Im wondering how best to power/switch them.

This is what im thinking - to use the KLIK plug in ceiling rose units connect up the lights, each one back to individual 6A mcb's in a three phase board. This will mean that there are 16 fittings on each phase - as i know that the units are 3.15A each then this is a total of 50.4A so ill use a 63A three phase main breaker.

Does this sound like a plan? - ive been wondering whether the whole system should be rated to the full ratings (i mean if there are 16 breakers at 6A then thats 96A, but as the quantities are known then i guess the diversity thing isnt an issue)

ONE LAST QUESTION - is it ok to use the MCB's as the switching device for each fitting? Im not talking about constant switching - just on at the beginning and off at the end?

I'm looking forward to some interesting replies!

Thanks in advance

 

[another_sparky]

3 phase I avoid - preferring to stick with domestic applications.

But, I'd throw in a view on your diversity question,

" The current demand of a final circuit is determined by summating the current demands of all points of utilization and equipment in the circuit. and where appropriate making an allowance for diversity.

Typical lighting current allowances for diversity:

1 a. 66% diversity in homes and individual dwellings.
1 b. 90% small shops stores offices and business premises
1 c. 75% small hotels guest houses etc.

Final circuits for discharge lighting must be arranged so as to be capable of carrying the total steady current, viz, that of the lamp(s)and any associated gear, and also their harmonic currents. Where more eaxct information is not available, the demand in volt-ampheres is taken as the rated lamp watts multiplied by 1.8. This multiplier is based upon the assumption that the circuit is corrected to a power factor of not less than 0.85 lagging and takes into accxount control gear and harmonic lagging. "
Source: IEE

Having done all the calculations for diversity... the IEE then state
" It is important to ensure that the distribution boards and consumer units are of sufficient rating to take the total load connected to them without the application of any diversity"

I read that as you needing a 96 amps.
But, we know the IEE regs are open to self interpetation!!

My other thought is, if say, in a normal dwelling there are 10 rooms
= 10 lights. these could easily run from one 6 amp circuit.

So, cant you run the lighting cables into a seperate circuits?
Say, four lights on each circuit.?

MCBs as daily switching? . I wouldnt advocate using them as individual switches on a daily basis!!

What about fitting a single Master switch ?

 

[ban-all-sheds]

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What about fitting a single Master switch ?

What about, as it's a club, using a professional electrician with certificates and public liability insurance. As keen as I am to wave the flag for DIY-ers in their own homes, I wouldn't advocate a non-qualified person working on a building where members of the public are admitted. You'd probably find your liability insurance null and void.

 

[another_sparky]

What about, as it's a club, using a professional electrician with certificates and public liability insurance. As keen as I am to wave the flag for DIY-ers in their own homes, I wouldn't advocate a non-qualified person working on a building where members of the public are admitted. You'd probably find your liability insurance null and void

Good point, ban. my fault for trying to offer a view]