lighting queston

[mysticalelectrickery]

i have 88 twin 80w luminairs what the best way to protect them over 3 phases??

 

[Evans Electric]

More info, please , what sort of fittings are they ? 80 watt ? ???

 

[mysticalelectrickery]

twin compact hf ballast 80w so 160w a fitting switching is being done by contactors so nay bothered about switch current rating, and they will be split over 3 phases but just wondering what size breakers to put in.

 

[steptoe]

average it out

30X160 per phase

its really quite simple,

sorry,

but Im not about to do first year calcs for you, thats why Ive got an apprentice to do them for me...

 

[Apache]

Can I have a go?

30 X 160W = 4,800

4,800/230 = 20.8 A

so are we gonna have to go for a 32A breaker?

 

[kme]

Nearly bud. Inrush allowance of 1.8.

I`d have delayed start , and either use a 32C, bringing 3/4 on first, then remainder; or else seperate them out into smaller circuits; which would be my own preference. More cable, but smaller cable.

Excellent try mate. If they all came on together, you`d have to use a 40A to allow for starting current. Otherwise, you`d be spot on. Well done.

 

[septiclecky]

I would personally put approx 30 fittings on each of the phases and then split these 30 odd fittings over 3 circuits each, so 10 fittings are on each circuit.

As don't forget as they are fluorescents eg discharge lighting the 1.8 factor for start up current should be taken into consideration when calculating the circuit design.

Maintainability must also be taken into consideration on the design as well so if you put lights on 3 breakers only a third of your lights go out whist working on that circuit.

 

[Evans Electric]

Can you enlighten me on these 80watt HF twin compact fittings ? What are they? the nearest fluorescent fitts are 70 watt x 6ft . any chance of a piccy ?

 

[mysticalelectrickery]

http://www.licht-123.de/xtcommerce/images/product_images/popup_images/24566_0.jpg

these will running on a DALI system on 12 zones in total and they detect presence and if no one is detected they will dim down to a pre-set level and also they adjust the lux level to compensate for daylight, pretty good energy saving system,oo and they also will be controlled via a plc to remote monitor the situation..

thanks all for ya help, i did do the maths before i posted but just wanted other peeps opinions and to see if others would do the same