[xero92]

How big/powerful of a generator would we need to get enough power to run a whole band (3 amps, a PA and speakers, some random extras...)? Any idea how much it would cost to purchase and operate for a night? Also any recomendations on what to buy? I've been searching craigslist, but I dont know quite what Im looking for. Thanks folks!

[hogan]

Rent one from Depot or your local rental house.
figure your power consumption like this:
100 watts per amp(not amplifier, but ampher like in a 15 ampher breaker)
so you've got 1500 watts to play around w/ on a 15 amp breaker
100 X 15
This is just an easy field rule of thumb that will keep you from doing something stupid.

if your 3 amplifiers are all 100 watts you've used up 3amps. If your PA is 1000 watts you are now at 1300 watts total or 12 ampher. Leaving you w/ 2 amphers left in that circuit for you extras.
You will be fine because I bet all your amps aren't 100 watts each and you're not running them full tilt the whole night. Let's say your bass amp is 400watts, you'll still be ok because none of these devices are going to consume their rated share of power at the same time if at all.
Most generators have to isolated outlets on them. Meaning each has a full 15 or 20 amp breaker on it. If you are really paranoid about it, split the equipment between the 2 outlets.
However if you are running lights and lot of them, put them on a seperate outlet so they don't sag your power at the amplifiers.

Also, use a nice heavy power cord to get from the gen to the stage.

~MJH

[RiverRat]

100 watts for 1 ampere is not a very conservative number... 75 watts for 1 ampere is a lot more conservative, that's using a Power Factor of 60%... 100W per ampere is a Power Factor of 83%. A 60% PF is industry standard, if I recall...

If you're real conservative... go 60W per ampere, you have quite a bit of wiggle room in terms of available power. Of course you'll be buying or renting more generator than you need... Better to have it and not need it, than need it and not have it!

[hogan]

100 watts for 1 ampere is not a very conservative number... 75 watts for 1 ampere is a lot more conservative, that's using a Power Factor of 60%... 100W per ampere is a Power Factor of 83%. A 60% PF is industry standard, if I recall...

If you're real conservative... go 60W per ampere, you have quite a bit of wiggle room in terms of available power. Of course you'll be buying or renting more generator than you need... Better to have it and not need it, than need it and not have it!

Yes. I didn't have the actuals in front of me or committed to memory. THat's why I said that it was unlikely that all the equipment would be drawing their max amount of juice at the same time if at all. Either way, the original poster is going to be fine. That is, of course, if his bass player isn't running a 1200 watt rig dimed and dropping bombs on every note.

~MJH

[deadguise]

Don't forget to get a nice long heavy gauge power distribution cable, you don't want the generator too close to the stage or audience. An AC Line Regulator (for surges and drop-outs) would be nice to have too.