fluorescent lighting with no starters

[N6rul]

Hello guys, I went and viewed a job today. The shop has 32 double battens divided into 5 15 amp breakers. The wiring is a nightmare. With the switches arcing and burning smell of the switches. Isolated switch with problem as that somehow is interconnected with another 4 mcb's. Just wanted to know if I calculate the lightings the same as any other. If im correct 15 amp mcb's are too high if a load. Can I reduce to 6 amp.
64 tubes
6400/230
27.8amps/5
5.56amps
So a 6 amp breaker should be sufficient if im correct. Please advise.
Gonna probably rewire the job. Hence need the advice. Thank you.

 

[Marvo]

Why would you want to reduce the size of the OCPD? The MCB is sized according to the cable CSA of the lighting circuit not the load. I doubt a 6A MCB will tolerate the start current depending on how many fittings are being switched simultaneously. I'd leave the MCB as it is unless cable size or installation method dictates otherwise.

 

[chopper76]

Don't forget your 1.8 multiplication factor for discharge lighting, or rule of thumb double it

 

[chopper76]

6400/230-=27.8x1.8=50.0/5=10.0amps

 

[Darkwood]

You need to go on further education to allow you to design lighting circuits as such, although you should know your multiplying factor as BASICS!! with inductive lighting loads also its good to have a switch rated 2x calculated load to allow for frequent switching of multiple inductive loads... I.E. 20amps in your case, I would also be informing customer that 8ft's are now obsolete and replacement lamps are no longer cost effective to buy as the tubes are excessively expensive.

 

[ian.settle1]

You need to go on further education to allow you to design lighting circuits as such, although you should know your multiplying factor as BASICS!! with inductive lighting loads also its good to have a switch rated 2x calculated load to allow for frequent switching of multiple inductive loads... I.E. 20amps in your case, I would also be informing customer that 8ft's are now obsolete and replacement lamps are no longer cost effective to buy as the tubes are excessively expensive.

If you can still get hold off them that is

 

[Darkwood]

£20 quidish at last call and yes getting harder to locate them ... ive been sticking 2 x 4ft together with tube extension couplers

 

[GLENNSPARK]

mate of mine has got loads of em....
his mill is in bradford by the way.....

 

[Darkwood]

Im changing about 100 8ft twins to 6ft twins in a factory with the better colour spectrum of the T8 and obviously the higher output efficiency against an old 8ft tube the light output is a lot better and pays for itself within a few years in energy saving .... another happy chappy ..... he cant believe how much brighter the place is an yr2 onwards hes saving loads on electric.

 

[telectrix]

bet you in 2 years time, you'll be swapping all them tubes for LED. they might be affordable then, once them little yellow men get their act together.

 

[N6rul]

great info

Hands up guys. Your right needed help with calculation. Did do it at college. Ive been working with company. Guys were not very helpful. Found electricians like me a threat. Hence left now and work for myself. I just cant do without this forum. A lot of u have been a great help. Many thanks. Hopefully one day I can teach others.

 

[GLENNSPARK]

bet you in 2 years time, you'll be swapping all them tubes for LED. they might be affordable then, once them little yellow men get their act together.

gooks Tel...gooks

 

[GLENNSPARK]

Re: great info

Hands up guys. Your right needed help with calculation. Did do it at college. Ive been working with company. Guys were not very helpful. Found electricians like me a threat. Hence left now and work for myself. I just cant do without this forum. A lot of u have been a great help. Many thanks. Hopefully one day I can teach others.

yeah....theres a lot of love/hate relationships goin on in here...