Lights per switch

[dwharrisnp]

I remember hearing that there is a limit to how many florescent lights (8 foot in my case ) you can put on a single switch. Is that true?

 

[HemiRambler]

Sure - like anything you've got to stick within the design limits. Circuit rating as well as switch ratings are different. It's not rocket science though - it's as simple as PIE.


EDIT: OK no more teasing ;-0 But be careful listening to me - I'm mechanical not electrical ! Here's what I remember

P (Power aka Watts)
I (Current aka amps)
E (Electricity aka volts)

So... P=I E

or a 40watt fixture = I * 120 volts


40/120 = I

.33=I

or stated 1/3 amp draw by a 40w load on a 120v circuit. So depending on your watts pretty much a LOT of them, probably to the point that you'd want to break them up into a couple different zones if for no other reason than to save some electricity - may not always need FULL LIGHTING.


So electrical types - how'd I do???

I remember hearing that there is a limit to how many florescent lights (8 foot in my case ) you can put on a single switch. Is that true?

 

[MrMark]

Yes, you need to look at the ballast to get the load amp rating for each light. Add them up. You should not exceed 80 percent of your circuit rating.

 

[Charles (in GA)]

If you use a 20 amp breaker and 12 gauge wire, just be sure and buy a 20 amp rated switch, not some cheapie. Your circuit is only as good as the lowest common denominator.

As noted, lighting is consider a continuous load and as such you cannot exceed 80% of the circuit's rating, 16 amps on a 20 amp circuit, and 12 amps on a 15 amp circuit. With fluorescent lights, this probably won't happen.

Charles

Charles

 

[MrMark]

Sure - like anything you've got to stick within the design limits. Circuit rating as well as switch ratings are different. It's not rocket science though - it's as simple as PIE.


EDIT: OK no more teasing ;-0 But be careful listening to me - I'm mechanical not electrical ! Here's what I remember

P (Power aka Watts)
I (Current aka amps)
E (Electricity aka volts)

So... P=I E

or a 40watt fixture = I * 120 volts


40/120 = I

.33=I

or stated 1/3 amp draw by a 40w load on a 120v circuit. So depending on your watts pretty much a LOT of them, probably to the point that you'd want to break them up into a couple different zones if for no other reason than to save some electricity - may not always need FULL LIGHTING.


So electrical types - how'd I do???

Not bad. Just take out the bold. Or, I suppose if you want to keep the "E" change it to Electromotive force.

 

[gatchel]

I always thought it was PIV and EIR...

 

[dwharrisnp]

Thanks for the help. I was under the impression there was something special about the balasts.

 

[mrb]

Thanks for the help. I was under the impression there was something special about the balasts.

there is. completely ignore the wattage of the lamps -you have to calculate based on the amps from the nameplate on the ballast.