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<blockquote data-quote="TJ Cornish" data-source="post: 137609" data-attributes="member: 162"><p>Re: Sound & Stage Power</p><p></p><p></p><p>Adding up the audio "wattage" will lead to a wrong answer for power consumption. Many products specify operating current, which is more real world. If you haven't already, read the article I linked to - this is explained there.</p><p></p><p>Briefly, many amplifiers are rated at two numbers - 1/8 power and 1/3 power. These numbers are designed to correspond with real music, and not trying to use your amp as a heater. 1/8 power is the right number for most musical genres, and indicates reasonable full-tilt-boogie - occasional clipping. The 1/3 power number sometimes specified indicates insane people who think the clip light is decoration and who enjoy visits to the speaker repair shop.</p><p></p><p>The reason you get more output power than required input power is that audio is not continuous. You get large spikes occasionally, and then, relatively speaking, long periods of low consumption. Energy storage in the amps (capacitors) buffer this, and the result based on many years of live data is the 1/8 power number.</p><p></p><p>A rule of thumb for products that don't specify actual power consumption at 1/8 power is to divide the output wattage by 3 or 4 to get an estimate of power consumption. I feel very confident that you can easily run 3 T12s per 20A 120V circuit, and very easily 4 T8s per 20A 120V circuit. On the sub side, you can get at least 2 boxes per 20A circuit. </p><p></p><p>That would be at most 3 20A circuits per side for mains and 3 20A circuits per side for subs; 12 120v 20A circuits total. This should all easily run on 100A split phase. </p><p></p><p>If it were me, I would try to take advantage of the universal power supplies in your rig and run at 208/240 volts when possible. This is a lot easier on your amplifiers, suffers much less voltage drop, and is potentially less wire, too. One option would be something like this:</p><p></p><p>Main distro is 200A 3-phase camlok input. Outputs are multiple circuits of 50A California and 30A L14-30. L14-30 fed via 10/4 cable to breakout boxes for 120v power. 50A California via 4/4 cable to breakout boxes providing 3 breakered L14-20 receptacles. </p><p></p><p>In many setups, you could run one California per side and probably run the whole non-sub part of the array on a single L14-20, and the subs on a second or possibly the remaining 2 L14-20s. For larger systems, a total of two Californias per side will provide more power than you will ever use.</p><p></p><p>A couple important principles: Every time you step down your ampacity, you need over-current protection. This means that your main distro needs to have 30A breakers and 50A breakers for the respective receptacles. Branch distros also must have breakers - an L14-30 breakout box usually has 4 20A breakers for the receptacles. Same on the California side - the 50A -> 3x 14-20 breakout distro needs to have 3 two-pole 20A breakers. It's not OK to chain your boxes from a 30A circuit, which is why you need to step down to 20A eventually.</p><p></p><p>There are other ways to do this, but 208v/240v power directly to your boxes is a really good thing.</p><p></p><p>Here's my real world experience:</p><p></p><p>I run ITech HD12000s, which are 8000w amps (12,000w by their most generous spec). I run these either from 120V power if that's all that's available, or 208v via L14-20 circuits if possible. One time I blew a 20A breaker with an amp, but I was being an idiot - sub duty in the 1/3 power range. Other than that "learning experience", they are more than fine on a 20A breaker. Interestingly, at the time of blowing the sub breaker, I was running two IT12Ks on a different 20A circuit powering the rest of the rig, and didn't blow the breaker.</p><p></p><p>Based on this data and other experiences, I have absolutely no concerns about running 2 8,000 watt amps on a 20A 208v circuit.</p></blockquote><p></p>
[QUOTE="TJ Cornish, post: 137609, member: 162"] Re: Sound & Stage Power Adding up the audio "wattage" will lead to a wrong answer for power consumption. Many products specify operating current, which is more real world. If you haven't already, read the article I linked to - this is explained there. Briefly, many amplifiers are rated at two numbers - 1/8 power and 1/3 power. These numbers are designed to correspond with real music, and not trying to use your amp as a heater. 1/8 power is the right number for most musical genres, and indicates reasonable full-tilt-boogie - occasional clipping. The 1/3 power number sometimes specified indicates insane people who think the clip light is decoration and who enjoy visits to the speaker repair shop. The reason you get more output power than required input power is that audio is not continuous. You get large spikes occasionally, and then, relatively speaking, long periods of low consumption. Energy storage in the amps (capacitors) buffer this, and the result based on many years of live data is the 1/8 power number. A rule of thumb for products that don't specify actual power consumption at 1/8 power is to divide the output wattage by 3 or 4 to get an estimate of power consumption. I feel very confident that you can easily run 3 T12s per 20A 120V circuit, and very easily 4 T8s per 20A 120V circuit. On the sub side, you can get at least 2 boxes per 20A circuit. That would be at most 3 20A circuits per side for mains and 3 20A circuits per side for subs; 12 120v 20A circuits total. This should all easily run on 100A split phase. If it were me, I would try to take advantage of the universal power supplies in your rig and run at 208/240 volts when possible. This is a lot easier on your amplifiers, suffers much less voltage drop, and is potentially less wire, too. One option would be something like this: Main distro is 200A 3-phase camlok input. Outputs are multiple circuits of 50A California and 30A L14-30. L14-30 fed via 10/4 cable to breakout boxes for 120v power. 50A California via 4/4 cable to breakout boxes providing 3 breakered L14-20 receptacles. In many setups, you could run one California per side and probably run the whole non-sub part of the array on a single L14-20, and the subs on a second or possibly the remaining 2 L14-20s. For larger systems, a total of two Californias per side will provide more power than you will ever use. A couple important principles: Every time you step down your ampacity, you need over-current protection. This means that your main distro needs to have 30A breakers and 50A breakers for the respective receptacles. Branch distros also must have breakers - an L14-30 breakout box usually has 4 20A breakers for the receptacles. Same on the California side - the 50A -> 3x 14-20 breakout distro needs to have 3 two-pole 20A breakers. It's not OK to chain your boxes from a 30A circuit, which is why you need to step down to 20A eventually. There are other ways to do this, but 208v/240v power directly to your boxes is a really good thing. Here's my real world experience: I run ITech HD12000s, which are 8000w amps (12,000w by their most generous spec). I run these either from 120V power if that's all that's available, or 208v via L14-20 circuits if possible. One time I blew a 20A breaker with an amp, but I was being an idiot - sub duty in the 1/3 power range. Other than that "learning experience", they are more than fine on a 20A breaker. Interestingly, at the time of blowing the sub breaker, I was running two IT12Ks on a different 20A circuit powering the rest of the rig, and didn't blow the breaker. Based on this data and other experiences, I have absolutely no concerns about running 2 8,000 watt amps on a 20A 208v circuit. [/QUOTE]
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