leeob77

hi everyone,
please excuse my possible ignorance but can anyone help with determining the current values for a flourescent fitting when determining max demand? (doing peer course and working through examples in the wiring regs first)
the question i cant get my head round has 30 x 40w twin power factor corrected fittings. (15 per phase over two phases).
it gives the answer as 0.46A per fitting? but i dont see how i can work it out without knowing what the power in the ballast etc is?

am i just being a bit dim?

cheers
Lee.

carlos1340

Lee,

I've tried my best to work this out......and can't get to 0.46A!!!! BUT, reading your other post, it would appear that the "PEER" questions come up with strange answers anyway!!!!

is the question referring to a domestic, or non-domestic installation??

leeob77

hi mate, the question isnt a peer one, its a worked example in the australian wiring regs! ive come across a few duds in there to be honest!
all i can think is they have neglected to give the power of the ballast?
ive emailed them to see. already spoke to them as another question on sockets in a communal area. they give a value of 2A in the new regs per socket but show a worked example using a value of 1A. they said it was just a misprint!

question related to a non domestic installation. so should be based on full load current. (table C2)

makes teaching yourself the regs hard work when your not sure if they have printed it right!

carlos1340

Lee,

it would appear that there is some information missing from example 5 in the regs.......

If you refer to HB300-2001(Electrical Installations- Guide to using the Wiring Rules), there is a worked example in there, that refers to twin 36W fluorescent lights rated at 0.46A each

Putting 2 + 2 together(and possibly coming up with 5), it might be that this is where the 0.46A comes from??????Maybe????

Good luck

Carl

leeob77

cheers carl.
dont have a copy of that but thanks for the input.
just checked in the peer workbook and their question gives a value for the ballast and the tubes so think its another mis print in the regs.
thanks for the help. sooner i finish this workbook and get the exam done the better!

lee.

steve`o

hi guys had a look at this and after scratchin me head ive come up with thsi

does it help ?? the 80w answer is extremely close to your .46A

leeob77

cheers steve o. apparantly its another misprint. should have included a value for the ballast. they also ommited values for duty cycles on welders on an example and gave the wrong value for sockets in a communal area. all misprints according to standards australia (i emailed them!).

thanks to everyone for your help.

finished the max demand part on peer workbook, cracking on with the rest of it now.

cheers.

lee.