Power draw of fixtures

[gbirdsall]

Hey guys I have a few questions that I hope you can answer.

What are the power draws of the fixtures you use?

I am kicking around an idea and need a range of data.
I'm looking for the Power Draws of ANY fixture that you know of that is actively used.
I do know the formula VxA=W but what I am looking for is the individual requirements of each fixture.
I am particularly interested in movers and LED fixtures as conventional should be easy to figure out. With movers I’m looking for the total energy needed to fully operate the fixture. Either by the minute, hour, or 12 hour block.


Also please correct me if I'm wrong but for a 500W, let's say PAR, the exact volts and amps are not set correct? So as long as VxA=500 the fixture will light and dim correct?

 

[Chris15]

Also please correct me if I'm wrong but for a 500W, let's say PAR, the exact volts and amps are not set correct? So as long as VxA=500 the fixture will light and dim correct?

So about that, yeah you're wrong...
A 500W lamp will draw 500W ONLY at its rated voltage. As voltage increases for a resistive load, so does current draw and thus power consumption.
It's not linear and I know there is a tonne of information about it all here if you look...

Remember that with a mover, the amount of power being drawn will depend on a number of variables including: age of lamp, how often teh motors are used, ambient temperature, etc. etc.
Likewise with an LED, it will depend on what intensity it is being run at...

What do you hope to achieve with the information you are seeking?

 

[Benjod82]

Conventional fixtures can vary by the type of lamp being used in them as Chris said, however when it comes to a mover or LED fixture the data sheet will almost always have its rated current in its data sheet or manual. No math needed (usually). For example we use ETC Selador Vivid-R fixtures here and at 120V they draw 125W of power at full intensity.

When in doubt I always look in the owners info. Sometimes I even round up to be safe.

 

[len]

I'm sure there are other places, but this site has LD Calculator Paul Pelletier (dot) com and it has a calculator/list (I can't remember which) for a lot of moving fixtures. It might be a good starting point. It also has stuff like a user database of case sizes, weights, etc., and a lot of other toys. I don't know the last time it was updated, but there it is.

 

[jhochb]

Good Morning

LD Calculator lite is a wonderful tool & I use it for almost all the show I do in 1 way or another.
DMX list, Load list, Voltage Drop, 3ph balancing, OHM's law, etc.........

Sadly, Paul is way too busy to update the libraries in it.
I add fixtures as I need. It takes little time & I have it for the next show.
BTW It’s a FREE program only for a PC

 

[JDurnford2011]

Good Morning

LD Calculator lite is a wonderful tool & I use it for almost all the show I do in 1 way or another.
DMX list, Load list, Voltage Drop, 3ph balancing, OHM's law, etc.........

Sadly, Paul is way too busy to update the libraries in it.
I add fixtures as I need. It takes little time & I have it for the next show.
BTW It’s a FREE program only for a PC

I can second that. There is also Showtool LD for the iPhone and you can measure Current, Voltage, Total Power, Unit Power, and number of units.

It also comes with a dmx calculator, dip switch calculator (My favorite feature I must say.), gel cuts, and beam calculations.

Heres a link for it so you can get a better idea. Daniel Murfin - Lighting and iOS Apps - ShowTool LD Home
-

Justin Durnford
LD
JustinDurnford.com

 

[icewolf08]

Hey guys I have a few questions that I hope you can answer.

What are the power draws of the fixtures you use?

I am kicking around an idea and need a range of data.
I'm looking for the Power Draws of ANY fixture that you know of that is actively used.
I do know the formula VxA=W but what I am looking for is the individual requirements of each fixture.
I am particularly interested in movers and LED fixtures as conventional should be easy to figure out. With movers I’m looking for the total energy needed to fully operate the fixture. Either by the minute, hour, or 12 hour block.


Also please correct me if I'm wrong but for a 500W, let's say PAR, the exact volts and amps are not set correct? So as long as VxA=500 the fixture will light and dim correct?

As people have mentioned, without actually metering the power usage at any given time, the best you can go for MLs and LED fixtures is the manufacturer's specifications. One example already given was the ETC selador, at full draws 125W. If you want to know how much power it draws over a period of time, you can do the math, just multiply watts by hours.

Generally, when we calculate loads for theatre/production applications, we calculate based on all loads at full power. This means when we calculate loads for MLs and LEDs and other devices, we use the specified max consumption to run the numbers.