AC current draw for a live band?

[slap-a-da-bass]

I'm wondering about power draw for our band. Our lead player has problems with one place in particular that we play, where his amp will fade in and out, then at times after several hours it will stay consistent, but louder than it originally had started. For me I think the answer is somewhere in his set up, but it is only at the one place we play.

Moving on to my question, I've made the move to powered subs & mains, and have been wondering if power is an issue. Is the consumption low on the class D amps? Is it not something to worry about? Here's our normal setup

• RCF art312a powered tops (2)
• QSC KW-181 Powered subs (2)
• Presonus StudioLive board
• Behringer RTA in the rack
• Two wireless mics in the rack
• Peavey & Line 6 DT25 guitar amps, both tube
• Pod HD500 & wireless set up
• GK RB 1001 bass head
• LED lighting, 4 bar tri's (2)
• Powered EV 112p monitor (1)
• Passive monitors with a old Crown XLS202 amp

The lead player also has his pedal board.

We've gotten pretty good with running power cables & knowing what extension cords get used where, so running the cables is really not an issue. I just wondering about popping breakers. Most places we play have all the power on one 15 amp circuit. We've never tripped a breaker, just wondering if we're close to doing it?

Thanks

 

[Big_Daws]

judging by what you have plugged into 1 15a circuit im suprised you haven't earlier...you should at least have 3 for that setup...

1 circuit for subs, 1 for tops, (or 1 per side) then 1 for stage. however if possible one circuit across the front for any pedals/anything else out front, and another across rear for amps etc....

you would probably notice a HUGE performance difference in your PA as well....

 

[slap-a-da-bass]

Not really sure how I can control what I plug into when the bars don't have it set up correctly, except for running a 50' extension cord.

 

[modulusman]

judging by what you have plugged into 1 15a circuit im suprised you haven't earlier...you should at least have 3 for that setup...

1 circuit for subs, 1 for tops, (or 1 per side) then 1 for stage. however if possible one circuit across the front for any pedals/anything else out front, and another across rear for amps etc....

you would probably notice a HUGE performance difference in your PA as well....

Those subs don't draw much power so you do not need a seperate circuit.

 

[modulusman]

Not really sure how I can control what I plug into when the bars don't have it set up correctly, except for running a 50' extension cord.

I would get 12 gauge 50 ft ext cords and try an find a seperate circuit at the place you are having problems. You should be fine with just 2 circuits.

 

[D.A.R.K.]

I suggest checking out the actual specs for the gear (should be easy enough to find out, the voltage requirements are usually printed next to the ac access on hardware) and doing some simple math.
This will tell you how much voltage you will actually need to run the setup.

 

[the Arsonaut]

well, voltage being more, or less constant...you'll typically find either a current rating, or a wattage (VA) rating alongside the voltage, near the power plug (or supply side). This is the amplifier's current draw, not it's supposed output power...(a 100watt amp can draw 250w-600w depending on its circuit).
Add your ampacities between each piece.

If it's marked with wattage or VA (voltamps, basically the same thing), divide by your voltage...let's use 110V (for US purposes, I don't trust them forrin voltages). This should give you a (close to) rated ampacity.

-To be on the safe side of circuit breakers, give them an 80% rating, meaning; don't load a 15a breaker over 12a.

-Keep systems together...tie in your PA together on one circuit, when possible. Those rack units don't draw all too much, and neither should a mixing board, for all of it's lights...

-if you have a difference in ground between one circuit in house, and another you can get noise, or a ground hum, or a nice shock everytime someone goes puttin' their lips all over the microphones. That's a microphone's way of saying NO.

That said, if you keep the PA system on 1 circuit, and your amp on a different circuit, and you kiss a mic, you can get that potential zap if there difference in potential grounds between the two circuits is large enough...that, or your amp(s) lacks a ground to begin with.

In theory, Class D & Class H amps should draw considerably less, than AB counterparts, but I would not assume having 2 amps of the same output wattage as having the same VA draw.

 

[Big_Daws]

Those subs don't draw much power so you do not need a seperate circuit.

you are right in saying but if you do the math, they are about 2a each, so thats 4a for subs and then 4a total for the tops...that leave a total of 7amps for everything else...half a 15amp circuit ain't much by the time that you add the bass and guitar amps, and pedals its getting insanely close...

 

[slap-a-da-bass]

Just played an outdoor gig last night, and had my subs on one circuit, and the tops on another, and there was a noticeable hum when we on break.

 

[Big_Daws]

try putting each side on a separate circuit. since they sub/tops are on separate ground it could be the cause...

 

[Hactar]

• RCF art312a powered tops (2)
• QSC KW-181 Powered subs (2)
• Presonus StudioLive board
• Behringer RTA in the rack
• Two wireless mics in the rack
• Peavey & Line 6 DT25 guitar amps, both tube
• Pod HD500 & wireless set up
• GK RB 1001 bass head
• LED lighting, 4 bar tri's (2)
• Powered EV 112p monitor (1)
• Passive monitors with a old Crown XLS202 amp

With this gear running at full power, some simple addition says you would be drawing somewhere around 28A.
Of course, you have not been running all this stuff flat out, and you never will. (Flat out in this context means running pink noise through all amps, at full volume.)
However, you should be using at least 2 separate circuits.
Typically, the stage/backline would be run on one circuit, while the amps/tops/subs/console would be run off another circuit.

Note that if the venue has been wired incorrectly, you may very well receive a shock.

 

[SactoBass]

• RCF art312a powered tops (2)
• QSC KW-181 Powered subs (2)
• Presonus StudioLive board
• Behringer RTA in the rack
• Two wireless mics in the rack
• Peavey & Line 6 DT25 guitar amps, both tube
• Pod HD500 & wireless set up
• GK RB 1001 bass head
• LED lighting, 4 bar tri's (2)
• Powered EV 112p monitor (1)
• Passive monitors with a old Crown XLS202 amp

"There's a slight possibility of overload."

 

[slap-a-da-bass]

I will make it a point to ask at future venue's. I've only booked one place that specifically told me about different circuits.

 

[modulusman]

you are right in saying but if you do the math, they are about 2a each, so thats 4a for subs and then 4a total for the tops...that leave a total of 7amps for everything else...half a 15amp circuit ain't much by the time that you add the bass and guitar amps, and pedals its getting insanely close...

Which is why I said to try and find two seperate circuits. You were the one who said the subs needed their own circuit.

 

[walterw]

with those LED lights, one 20A circuit should be plenty for everything. (big old-school par cans suck way more power than typical bar PAs ever do.)

separate circuits are great, especially for the subs amps, but they're often a luxury when you're getting to your power outlets by moving the jukebox down at stingy steve's drink emporium.

also, unless those separate circuits are really installed right, you get problems with ground-loop hum and that exciting mic/lip electrical interaction that arsonaut mentioned.

 

[Big_Daws]

Which is why I said to try and find two seperate circuits. You were the one who said the subs needed their own circuit.

yeah i thought that they were closer to 5amps each until i actually took a look..

 

[two fingers]

Man, I have played some dives in my life, but never a building that I couldn't find a couple of circuits to plug into. And if a club owner gives you crap over something like that, you need to never play there again. I have told many club owners "You are either in the live music business or you aren't. And if you are, you need power on the stage..... several circuits. Period."

Of course, I have reached the point in my life that I don't depend on my bass to make my bills, so I have that luxury of a big mouth. Worst case for me is that I don't go back there. And if he's going to stand me down over electricity, he can have it.

 

[warnergt]

Man, I have played some dives in my life, but never a building that I couldn't find a couple of circuits to plug into.

Same here. Sometimes you have to unplug two Coors Lite
signs to get enough power.

 

[two fingers]

Same here. Sometimes you have to unplug two Coors Lite
signs to get enough power.

Well, "Vortex of sin and degradation" (the location in your profile) must be somewhere in NC because I think I played that bar! I think we just used one of those screw in adapters in place of a light bulb for a third circuit strung from the ladies bathroom.