Adding fluorescent lights

[antkn33]

I have a 60 amp sub panel in my garage. It currently has one 15 amp breaker for the six fluorescent fixtures.
I would like to add three more fixtures. Is it safe just to add them to current set up, just wiring it to the existing fixtures? Or will I have to add breakers? I have two open slots in the subpanel.
Thanks

 

[Highbeam]

Modern 8 foot long tube fixtures hold 4 -four foot t-8 bulbs and draw one amp per fixture.

You have a 15 amp circuit and if the current 6 fixtures are also one amp each than you can safely put three more on the same circuit.

 

[regguy1]

I have 10 48" 2 tube T8's on each 15 Amp breaker, you can see them in the video linked below

 

[antkn33]

Thanks I couldn't figure out how many amps a fixture draws.

 

[eljefino]

If you want to be elegant, put the extra set of fixtures on another switch. Turn them on one at a time, it will spread the start up surge out. 32W/125V= .25 amps per bulb as mentioned above, but double it for brief start up surge.

If it would be pitch black without, it could be a good idea to have it on two breakers just in case one pops. Or to have that breaker just for lighting, or a work lamp plugged into an outlet, etc.

Edit: also consider if you have 49 cent switches they are probably only rated for 500 watts. "HP rated" ones can take the full 15 amps/ 1875 watts.

 

[pipsters]

When you buy the lights they have the amp draw on the box. IIRC my 2x 4-foot T8 fixtures draw 1.8 amps each. There is some code issue with lights, I want to say 80% load so max of 12 amps continuous use, might want to check into that.

 

[pattenp]

Is 2X 4-foot a two tube 4 four foot fixture? The reason I ask is 1.8 amps is very high for a 4ft 2 tube T8 fixture. Usually that size takes less than 1 amp.

When you buy the lights they have the amp draw on the box. IIRC my 2x 4-foot T8 fixtures draw 1.8 amps each. There is some code issue with lights, I want to say 80% load so max of 12 amps continuous use, might want to check into that.

 

[pipsters]

Is 2X 4-foot a two tube 4 four foot fixture? The reason I ask is 1.8 amps is very high for a 4ft 2 tube T8 fixture. Usually that size takes less than 1 amp.

It was this one, packaging said 1.8 amps but I'll look it up in a few days when I get home

http://www.homedepot.com/h_d1/N-25e...53&langId=-1&keyword=shop light&storeId=10051

That being said it takes two 32 watt bulbs so 64 watts/120 volts = about 0.5 amp, so not sure why the consumption would be 4x as high.

 

[mmhouse]

It was this one, packaging said 1.8 amps but I'll look it up in a few days when I get home

http://www.homedepot.com/h_d1/N-25e...53&langId=-1&keyword=shop light&storeId=10051

That being said it takes two 32 watt bulbs so 64 watts/120 volts = about 0.5 amp, so not sure why the consumption would be 4x as high.

Temporary spike at start-up?

 

[Highbeam]

The fixture and/or the ballast will have the amp draw listed. My 4 bulb 8 foot t8 fixtures from HD were under 1 amp and the 4 foot t8 two bulb fixtures I put in today were 0.8 amps each. You can't just add up the bulbs.

 

[ssotangkur]

(No of T8 Bulbs) * 32W + (No of T12 Bulbs) * 40W > 120V * 15amp * 0.8 safety factor == Whether you need a new circuit