Electricity + Maths = A)fire B) smoke C)WIN?

[Karnage]

So here is a theoretical question, of course no-one condones unlicenced electrical work, so this is purely for circuit design purposes. This is based on the Australian 240-250V single phase system.

Volts * AMPs = Watts

so 240 * 10 = 2400

lets say 80% safe usage = 1920 W

a single fluro tube is 18W so this allows for 106 fluro tubes off of a single 10A circuit

This just doesn't sound right, is this correct?

 

[JCByrd24]

I can't see how you are wrong, maybe round down to 100 to be safe!!

 

[rockwithjason]

you don't calculate the load off of the wattage of the lamps in a florescent application. you add up the amp rating of the ballast. and yes you can have many many tubes on a single circuit depending on the voltage.

 

[Charles (in GA)]

What doesn't seem right is the bulb wattage. A 4 ft T8 is something like 32 watts. A watt is a watt, doesn't matter if its in Oz or the US. You really need to look at the current draw of the fixtures, and calculate off that to be slightly more accurate.

Charles

 

[Nostraquedeo]

Your math looks right, but I would question your actual fixture wattage. You need to figure bulb wattage and ballast wattage to get the total wattage of the fluorescent fixture.

 

[NUTTSGT]

So here is a theoretical question, of course no-one condones unlicenced electrical work, so this is purely for circuit design purposes.

What is wrong with unlicensed electrical work ? As long as it is done properly and doesn't require a certified electrician by code.

Just because somebody is licensed doesn't mean it is going to be done properly, (now you electricians don't get your ******* in a bunch) that's like saying just because somebody went to college, they're smart.

 

[AZ Garage]

Forgot to add in the %125 for continuous load per the NEC...

My calculations are based on the 18W lamps 18 * 1.25 = 22.5(23W) 1920/23 = 83 lamps, NOT fixtures...

 

[Karnage]

What is wrong with unlicensed electrical work ? As long as it is done properly and doesn't require a certified electrician by code.

Just because somebody is licensed doesn't mean it is going to be done properly, (now you electricians don't get your ******* in a bunch) that's like saying just because somebody went to college, they're smart.

Whilst I agree wholeheartedly, I didn't want to start a debate on the matter.

Thanks for your input guys, I spoke to a sparky about it and he is happy for mt to run 48 X 36W fluros off 10 amps, but he suggested I run a 15A 4 switch gang, and run them in banks of 12.

In case you are wondering why I wanted to do this its for an airbrush / spray room, the lights will be recessed and sealed from the room also.

 

[DeSloth]

Thanks for your input guys, I spoke to a sparky about it and he is happy for mt to run 48 X 36W fluros off 10 amps, but he suggested I run a 15A 4 switch gang, and run them in banks of 12.

I'll look for the glow on the horizon.

Make sure you remember to insulate your ceiling cavity with foil.

 

[hidollartoys]

Forgot to add in the %125 for continuous load per the NEC...

My calculations are based on the 18W lamps 18 * 1.25 = 22.5(23W) 1920/23 = 83 lamps, NOT fixtures...

Fluro wattage IS calculated from the ballast not the tubes!!!!!!!!! 125% "continuous" is only required for commercial applications.

 

[Charles (in GA)]

125% "continuous" is only required for commercial applications.

Can you cite the code section where this is found? I cannot find it.

Charles

 

[hidollartoys]

Can you cite the code section where this is found? I cannot find it.

Charles

Can YOU quote the article that requires residental lighting to be considered as continuous loads??????

 

[rburke65]

Now you've done it!

 

[HTGTS350]

Unlicensed electrical work is highly illegal in Australia and can land you in jail. If you are caught doing unlicensed electrical work your electricity supply will be removed, you will be fined and you won't be allowed to have electricity back until your property has been inspected and deemed safe and beleive me, if your property is being inspected the inspector will deem it unsafe and ensure you need to have thousands of dollars of rectification work done before you get your supply back.