Three 400w'ers on one standard 110v 15amp circut?

GreenMONSTAH

Well-Known Member
Hey I always thought 2 400w was the max for one circut idk why, but I actually did the math and realized I could have up to 3 and be within the boundries. Is this true or did I just miss something? (also my lights run at 430w instead of 400w idk if thats normal but figured id throw it out there) Thanks for any help in advance fellow tokers :)
 

unohu69

Well-Known Member
No idea, but im just as curious as you. I have a 175w MH plugged in, and i was scared to plug in an additional 100w HPS. but now im thinkn ill be safe. ope to hear from some one more knowledgeable than me on the subject.
 

GreenMONSTAH

Well-Known Member
Ohh you'll be good with both those on one outlet for sure, gettin a double spectrum goin on huh lol nothing beats that. I usually have two 400w on one socket never had a problem but now I got one more in theyre so ill know in a few hours at 8am if its to much of a load to bear hope not!
 

unohu69

Well-Known Member
lol, I wasnt goin for the dbl spectrum specifically, but its all I got. I cant afford nor do I have the space to run anything bigger. I just figure more light the better, even if the color is off a little.
 

GreenMONSTAH

Well-Known Member
I feel you lol im addicted to adding light to my room. But having that meatal halide will def help improve your trich production and flavor so good call throwing that on your ladies, what you got going if you dont mind me asking?
 

MrEDuck

Well-Known Member
3 400W lights are fine on a 15A circuit. They pull like 3.6A. I wouldn't try to run anything else on it, but they'll all fit.
 

fireproof

Active Member
Best thing to do is plug them into a "kill a watt" and see how many amps they actually pull. Then trace out the circuit and make sure its not possible for something else to "accidentally" get plugged into it if you didn't add the line for the specific purpose of using it here.
 

Randm

Active Member
3 400 amp = 1200 amps. you have a 15 amp line. This MAXES this line out. Do not use it for anything else. Fans, pumps, etc all must be on a separate circuit. The rule is 85% of circuit amp rating to be on the safe side.
 

ceestyle

Well-Known Member
power = current * voltage

400w = current * 110v (if you're in the us)

Each lamp therefore draws ~3.6A, as MREduck said.

Three lamps = 10.8A
 
3 400 amp = 1200 amps. you have a 15 amp line. This MAXES this line out. Do not use it for anything else. Fans, pumps, etc all must be on a separate circuit. The rule is 85% of circuit amp rating to be on the safe side.
The 85% rule is something I heard. Thanks for reminding me. Im a little confused with the other I said 400 watts of electrical and 500 watts of cfl and assorted electric on a 20 watt. You say I have a 15 amp line (.85x2000=1700) and say it maxes out but it seems I have plenty of room (maybe 500 watts). I honestly Know little about electricity.

Thanks for your help.
 
power = current * voltage

400w = current * 110v (if you're in the us)

Each lamp therefore draws ~3.6A, as MREduck said.

Three lamps = 10.8A
I think you mean * for multiplication
I have no idea what the ~ means.
I do not understand the MREDUCK reference
Cannot follow what you say.

I can see you have been here a long time. I appreciate your concern.

I tried reading Lumens, lux, and adding it all up but only slipped deeper into confusion. It has become far too long. The info at the beginning was great and way beyond me.

I appreciate your help
 

snocat

Active Member
if you look on your ballast there should be a tag on there with how many amps it draws,I know that magnetic ballast draw a little more than digital ballast,if you have 15 amps available you dont want to draw a constant 15 amps or it will overheat and trip,I personaly would use around 12 amps on a 15 amp breaker and thats the max,also dont have the 3 lights come on at the same time because they draw more power on start up,just set the timers a minute or two apart and you should be good
 

andar

Well-Known Member
willy. * means multiplication. ~ means (about/estimation) MREDUCK posted this in the thread that he refrenced > 3 400W lights are fine on a 15A circuit. They pull like 3.6A. I wouldn't try to run anything else on it, but they'll all fit.
what he said made perfect sense. good luck.

//also might want to google ohms law.

// also dont listen to RANDM his information is innaccurate. those light are 400 watt not amp. amp is measurement of current. watt is measurement of power. once again google ohms law
 
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