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[Stephen Swaffer]

That's because, as Ivan always says, it depends.

If you use a 16 AWG 100 ft extension cord on a 10 amp load, ampacity says it will handle it-by that definition, it means the insulation won't melt off of it.

However, at that distance with that load you will have approximately 8.3 volts, or 6% voltage drop.  Technically, 6% is more than the NEC recomends.  If you are running incandescent lights, the lights won't care-their maximum brightness will just be 6% less.  If your gear has "universal" power supplies rated from 100-277 volts-they probably won't care either-IF the voltage out the outlet is in fact 120 VAC.  OTOH, if it is already questionable-say 112 VAC, now you are at 103.7 and right on the edge of being "okay".

Furthermore, while heating/ampacity is concerned with average draw, voltage drop is dictated by ohm's law and affects even peak loads, so if you have a loud peak and draw 20 amps, now you have a voltage drop of of 17.5 volts and if the receptacle started at even 115 volts, now you are down to 97.5 and have a potential drop out.

When you are dealing with any distance, "ampacity" is usually less of a concern than voltage drop.  Ampacity issues cause fires and safety issues, so they are usually regulated.  Voltage drop is an engineering concern of proper operation of equipment-so the question becomes "How reliable do I want my setup to be?"

Keep in mind that even the voltage available at a given receptacle can vary some with the load on the grid-which changes depending on the time of day and the weather.  With that in mind, a margin of error is a wise thing.

[Tim McCulloch]

I am ordering 5 Galaxy Powered PA6S Hotspot Monitors for our touring band.   We need individual monitor mixes sent to each player using Behringer P16 units.  The P16s will be all be daisy chained via Cat5 cable.   I would also like to daisy chain the powered hotspots from one outlet.  Because of our usual stage setup, I need the following lengths of electric cable: (4) 20ft,  (1) 50ft.   Currently, I've ordered these electric cords in 16 gauge but I'm worried that I may need to go with a thicker gauge if they're all daisy chained together.  My research has shown that a 16 gauge cord up to 100ft will handle 10 amps.  The Galaxy PA6S is rated at 170 watts. 

How can I know if 16 gauge wire will handle 5 of these Galaxy hotspots?

After reading this thread to date, my answer is NO.

Not that #16 will fail dramatically or catastrophically, but that your use as an extension cord/stringer on stage requires larger conductors and extra-hard service rated cable.  Stephen's comments about voltage drop should be taken seriously, too.

You are not "daisy-chaining".  That term typically is applied to running the service to the first unit and then, using an AC outlet on that unit, powering the next unit in line... repeating until there is nothing left to be powered.

I think what you really want is a "stringer".

http://www.thetapeworks.com/tape/index.php?main_page=product_info&cPath=31_128&products_id=448

There are other suppliers of similar products with different outlet spacing (our symphony bought some with 6 ft spacing to have AC for music stand lights) but you'll need to do your own search...

[Richard_Blythe]

I just heard back from galaxy audio and they said that PA6S units have a 600ma draw.  Simple math of my 5 hotspots yields the result of: 3 amps.  I just looked on home depot's website and they say that 16 guage wire can handle 10 amps at 100ft.  So Ivan Beaver, you were correct that I can use 16 guage cable.  Thanks to everyone who responded to the thread!

[Rick Scofield]

I just heard back from galaxy audio and they said that PA6S units have a 600ma draw.  Simple math of my 5 hotspots yields the result of: 3 amps.  I just looked on home depot's website and they say that 16 guage wire can handle 10 amps at 100ft.  So Ivan Beaver, you were correct that I can use 16 guage cable.  Thanks to everyone who responded to the thread!

Yep, right up until one of the musicians plugs in his fan, or guitar amp, or something else with a greater draw.

In other words, you're not leaving much room for error. Maybe.

[Stephen Swaffer]

How much Pro audio gear does Home Depot sell?

[Stephen Kirby]

More to the point, how much code compliant entertainment production does Home Depot do?

If you put this in a sheath it might not stand out so much, but there are other codes for mixing power and low voltage together in one cable.

[Tim McCulloch]

I just heard back from galaxy audio and they said that PA6S units have a 600ma draw.  Simple math of my 5 hotspots yields the result of: 3 amps.  I just looked on home depot's website and they say that 16 guage wire can handle 10 amps at 100ft.  So Ivan Beaver, you were correct that I can use 16 guage cable.  Thanks to everyone who responded to the thread!

NO.

Ivan is correct that 16AWG will not catastrophically fail, melt down or catch fire.  He did NOT say it was up to Code for use on indoor stages or in outdoors entertainment applications - which it is not.

[Richard_Blythe]

How much Pro audio gear does Home Depot sell?

Wait, Home Depot is not a music store??  I don't know how I could I have missed that.  Could you suggest website that will tell me something other than a 16ga extension cord can handle up to 10 amps at 100 feet?

Ivan is correct that 16AWG will not catastrophically fail, melt down or catch fire.  He did NOT say it was up to Code for use on indoor stages or in outdoors entertainment applications - which it is not.

So Tim, are you you saying that 16AWG is not up to Code -- regardless of the length?

[Tim McCulloch]

So Tim, are you you saying that 16AWG is not up to Code -- regardless of the length?

That's correct, except that length is irrelevant to my point...  NEC Article 520 requires cables used on stage to be "extra hard service rated" which means no "J" in the type designation (S, SO, SOO, SOOW, SOOEW).  IIRC 520 also requires 20 amp circuits, so running a #16 cable on a 20 amp circuit is a big and obvious no-no.  Even with a 15 amp breaker, #16 is only rated for 10 Amperes.

Richard, you're only looking at this from the "will the cable fail" and voltage drop over the run (which I suspect will be greater than anticipated as audio has peaks that will exceed minimal current draw ratings).  You also need to look at what Code requires.

In addition to the general use articles (200, 300, 400) our work falls under 520 and 525, with some exceptions to 300/400 in 640.  You don't need to become a Code expert, but I point these out because it's easy to assume that something is safe when only some of the considerations are examined.

[Richard_Blythe]

That's correct, except that length is irrelevant to my point...  NEC Article 520 requires cables used on stage to be "extra hard service rated" which means no "J" in the type designation (S, SO, SOO, SOOW, SOOEW).  IIRC 520 also requires 20 amp circuits, so running a #16 cable on a 20 amp circuit is a big and obvious no-no.  Even with a 15 amp breaker, #16 is only rated for 10 Amperes.

Richard, you're only looking at this from the "will the cable fail" and voltage drop over the run (which I suspect will be greater than anticipated as audio has peaks that will exceed minimal current draw ratings).  You also need to look at what Code requires.

In addition to the general use articles (200, 300, 400) our work falls under 520 and 525, with some exceptions to 300/400 in 640.  You don't need to become a Code expert, but I point these out because it's easy to assume that something is safe when only some of the considerations are examined.

Thanks Tim.  When I received the reply back from Galaxy Audio, I assumed that I was getting the total current draw of the speaker.  So I guess the obvious recommendation would be 12AWG cable

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