Simple math

[Tom G]

Good morning! Having a problem with simple math. I have 131 LED lights at .9 ma .9 multiply by 131= 117.9 amps seems high

 

[infinity]

Your multiplier it incorrect .9 milliamperes is .0009.

 

[Tom G]

Your multiplier it incorrect .9 milliamperes is .0009.

Thank you! Iam in disbelief that 131 Led lights at 900ma total .1179 amps unless I have to move decimal point

 

[david luchini]

Good morning! Having a problem with simple math. I have 131 LED lights at .9 ma .9 multiply by 131= 117.9 amps seems high

Thank you! Iam in disbelief that 131 Led lights at 900ma total .1179 amps unless I have to move decimal point

You changed the fixture current from 0.9 mA in your first post to 900 mA in your second post. Which is correct.

 

[infinity]

I think that .9 mA is too low for any light fixture.

 

[LarryFine]

The 900ma (0.9a) sounds more likely. And yes, well over 100 lights at almost an amp each will exceed 100 amps.

 

[Tom G]

The 900ma (0.9a) sounds more likely. And yes, well over 100 lights at almost an amp each will exceed 100 amps.

Thank you the lights are going to be on a 277 volt circuit

 

[Tom G]

Thank you

 

[david luchini]

Thank you the lights are going to be on a 277 volt circuit

What type of fixtures are these? I haven't seen very many 250W LED fixtures.

 

[bwat]

Continuing on the math piece, I can suggest doing some "close enough" math in the future if it ever seems like the results might not be making sense. Round numbers so that it's easy enough to do without calculator for example. If the numbers are within magnitude, then you have more confidence that it was correct what you did. I do it quite often for a sanity check.

Ex:
900mA = 0.9A... so "almost" 1 amp per light. So if you have 131 lights and almost 1 amp per light, you'll know your answer should be to have "almost" 131 amps. So 117.9 amps passes the 'sniff' test.