Lots of lights on a circuit

[Blowcat]

Hi I wonder if someone of you could give me your thoughts.
Done a condition report on a hall.
They have 7 - 6amp MCB's feeding lighting circuits.
Each MCB has two 1.5mm T&E cables run in a ceiling.
There are 90, 45, 80, 50, 57, 49, 50 down lights on each circuit.
There are no reports of circuits tripping, as a whole the installation was pretty good.

Is there cause for concern regarding the number of fittings per circuit.
I never got the wattage of the 230v lamps.

I feel there is potential for over loading the cable but with no signs of tripping I cant think what to advise.
What do you think????

Regards
AJ

 

[Marvo]

If the MCB is sized correctly for the cable and there's no tripping issues then it's not a problem.

 

[Blowcat]

Cheer Marvo, I know you right but I sometimes get a bit jittery when I see over 30 lights on a circuit. I know the circuits can be divided at the DB by splitting the 2 T&E cables and in theory split the number of points by half.

 

[shanky887614]

if they were led then no issue.

900 watts at most from the first one.

thats just over 4 amps off top of head.

most people use 5watt led's so no issue

 

[Octopus]

Are you sure that 90 on one MCB? -at 35 watts per fitting I make that about 13A That said the cable is good for about 17A so hey whats the problem!

How are they arranged? How does the diversity work out?

 

[shanky887614]

Are you sure that 90 on one MCB? -at 35 watts per fitting I make that about 13A That said the cable is good for about 17A so hey whats the problem!

How are they arranged? How does the diversity work out?

you can get led alternatives to everything now, bayonet cap, edison screw the lot

 

[Baker1988]

Are you sure that 90 on one MCB? -at 35 watts per fitting I make that about 13A That said the cable is good for about 17A so hey whats the problem!

How are they arranged? How does the diversity work out?

35 watts per fitting seems a bit much for led downlighters I thought leds was about 10 watts like these ones are only 7watts max
http://m.NoLinkingToThis/description.htm?id=82308

 

[Octopus]

you can get led alternatives to everything now, bayonet cap, edison screw the lot

I realise that but the OP doesn't mention LED's just the quantity of lights and I was speculating the potential load!

That said, just imagine the inrush currents!

 

[Darkwood]

At over 400 lamps the biggest surprise is that there is any ceiling left space wise, I would also suspect diversity plays a key role here although its probably been work out with too much applied, even if it was LED it would need a very large no' of switches to divide the inrush up of the drivers .... regardless of access to the lamps I would have switch them all on and clamped the load if I came across this.

If indeed they are LED and have large switching banks then not a problem but if for instance they are GU10 then each lamp has to be calculated for the largest lamp that can be fitted which would be 50watts not what lamp is in during inspection ...so many installs are designed wrong due to the calcs been based on the lamp fitted and not what could be fitted.

 

[Parker27]

I would make a point of finding out what the wattage of the current bulbs are, its all speculation up to now.