How many LEDs can fit on an outlet?

[DBPC]

First let me say that I am probably most accurately described as a designer who does electrician work. I am fairly weak on the actual numbers and theory of electricity, especially compared to others in the field.

So my understanding is that a standard American outlet is 120v, 20 Amps. My question is, assuming the outlet has the breaker to itself, how many LED fixtures can I fit on it?

As far as the fixture goes, I'm looking to rent LEDs that get the most light out there.

Thanks for the help, I'm new here and looking forward to helping out in the community!

-DBPC

PS: I should mention that this is extremely helpful for a budget I need to finish by tonight Thanks!

 

[Footer]

Never assume 20, many places are wired for 15.

Biggest question is... what kind of LED units?

 

[JD]

For a continuous load, you need to de-rate the circuit a bit. So, lets say you have a solid 16 amps to work with. The next step is to find out what the maximum gross wattage load of each fixture is. (Gross wattage includes any wattage lost in the power supply or control circuit.)

So, for example, lets say the fixture has a gross wattage of 150 watts. 120 volts times 16 amps tells us you have 1920 watts available for the fixtures. Divide that by 150 watts and you come up with 12.8 or, 12 fixtures for sure. You could probably put 13 on with no problem in continuous duty mode.

Note: A 15 amp circuit would de-rate to 12 amps for a total load of 1440 watts, or 9.6 fixtures.

 

[DBPC]

Thank you for the quick, informative replies.

As far as de-rating goes, how little can I de-rate without risking too much?

This is a Philly fringe show and I'm trying to squeeze out as many fixtures as possible. For the first time in the history of fringe however, I think my issue is power distribution, not budget. The venue is not a typical theater, it's mostly used as a large art gallery.


I've yet to hear back about their power set up (emailed them today), so I'm just trying to cover all my bases. I'm not sure of a way to get traditional fixtures into the space, if they don't have a mass load of power for me to set some dimmers up to, just lying around.

 

[MisterTim]

First let me say that I am probably most accurately described as a designer who does electrician work. I am fairly weak on the actual numbers and theory of electricity, especially compared to others in the field.

Stop right there and go read some books on electricity. Seriously. No offense, but you shouldn't be coming near any "electrician work" with a 10-foot pole if you can't figure out how many fixtures you can put on a 20A circuit. Don't mess around with electricity. Ever.

With that said, JD has your answer.

 

[DBPC]

Stop right there and go read some books on electricity. Seriously. No offense, but you shouldn't be coming near any "electrician work" with a 10-foot pole if you can't figure out how many fixtures you can put on a 20A circuit. Don't mess around with electricity. Ever.

With that said, JD has your answer.

None taken, however I'm not wholly ignorant on the subject. I'm used to working in already rigged theaters (big and small), I've never been faced with designing and running a whole show off of what amounts to five outlets.

I've never been TD nor concerned myself with those specifics, although I know the limitations that exist and I do understand the basic concepts. I came across this forum and figured a knowledgeable community could confirm my research or improve upon my knowledge of the situation. I'm happy to find I was right.

 

[JD]

If you have five outlets to deal with, then what you want to find out is:

1) Are they on separate circuits?
2) What is the current limit on these outlets (15 or 20)?
3) Is anything else plugged into these circuits?

Number three is critical because if there is other equipment on those circuits, all bets are off. If they are dedicated circuits, then it's just a matter of doing the math.

The next step is to find out how many gross watts each of your LED fixtures is using.

 

[DBPC]

I've been waiting on the venue's reply to all those questions, unfortunately they've been slow in reply. Without knowing the power available it's impossible for me to price out the fixtures (which I'll choose based on a balance of quantity of lights versus the wattage available), let alone any sort of dimming system for them. You've been very helpful, thanks.


Any recommendations on LED fixture brands/models? I tried a rudimentary search around the forum but didn't see anything. This is a theatrical show so the more oomph the better, hopefully there are LED Par 64s capable of that? Last time I looked into them the general population was pretty weak.

 

[DuckJordan]

The biggest issue that I can see is that your looking at how many you can put into a circuit. The next issue is how are you going to transfer the the power through out the room to the lights (they are probably not going to be in a single location). The next thing to think about is what you want for functionality out of the light. I understand you are a set designer and not so much a lighting designer but one thing that will make your life easier is to look into the mcandleless method (sorry if i spelled that wrong its late and I just got done with an opening night of a children's show). Denoting functionality will definately help you with choosing fixtures and where they should be placed.

 

[metti]

Renting or buying? I'm going to assume that you are renting since this isn't for a venue so what makes/models you can choose from is going to be limited by what is available from local rental houses. I'm sure someone around you will have CK ColorBlast TRs or CB12s, someone will have ColorBlaze 72s or a similar striplight, and someone will have some sort of LED PAR. Beyond that you are just going to have to ask around. CBers can probably help you choose once you have a list of possibilities but there isn't much point in our making model suggestions until we know what models you have available. Also, the number of fixtures per circuit depends 100% on the fixture type. A Chauvet ColorDash Accent (.1A@120v) takes a lot less power than a Vari-Lite VLX (roughly 10A@120v).

 

[mstaylor]

Around the Philly, NJ, northern DE area you have a large choice of rental houses. Call around and see what equipment is available then we might be able to help you.

 

[bishopthomas]

How many fixtures do you need? I'm in central Jersey and have 108 watt LED pars that are pretty **** bright. I use them for color wash along with 750w S4's for specials. I have both RGBA and tricolors. Send me your email and I'll get you pictures if you're interested.

Thomas
[email protected]