fluorescent lights

[trick28]

Hi All,

I am about to instal 100x30w fluorescent lights and was wondering if there are any rules that I have to apply in terms of switching these lights as I am concerned about having so many lights switched off one switch.

I also have been asked to install the lights using gear tray that allow 4 lights to be controlled of one tray. I have only ever used one ballast per light and was wondering if there are any hidden gremlins with these multiple trays.

 

[davelerave]

what are they? T5

you can use multipole contactor/mcbs if you have to use one switch

normally a few switches,circuits- for maintenance ,avoidance of blackout etc.

 

[trick28]

the lamps are indeed t5s. I was planning to split the circuits into 3x6A c type breakers, an use 8 switches. Does this sound reasonable?

 

[jeremy]

I think though am not 100% that design current for fluorescents should be twice that of running load. Not sure where I remember this from.Maybe split it into 3x10s? Type c definitely

 

[davelerave]

3 6A C type will be too tight anyhow


as far as i can tell a correction factor isn't needed for Hf ballasts

also Mk switches etc. don't require de-rating for fluorescent loads


there may be a bit of accumulated earth leakage with the HF ballasts ,not sure on harmonics-don't think it's a major issue

 

[trick28]

do you think that I should go for 3x10A c type breakers ?
I was also planning on breaking the switching up into 1 switch per 8 lamps using a 10 way switching panel.

I am using 1.5mm cable with the longest run being approx 20m

 

[davelerave]

http://www.tlc-direct.co.uk/Book/6.2.1.htm

the method was a factor of 1.8 for demand and a factor of 2x again for switches

not as relevant now with the HF ballast and MK switches etc. except for number 3 -harmonics

i would be thinking 'minimum' 3 C10 or 5 C6 allowing for some losses etc. and not loading the circuits too much -the c6 may suit better for Zs and VD