power generator

[CraigB]

Hi Guys, I need help trying to figure out what power generator specs I need to power my band outdoors.  My guitar amp, a bass amp, keyboard amp, three keyboards, and PA.  Thanks in advance for helping me out!

[eleventeen]

You have to add up all the power consumed by all the devices and then add a safety / comfort factor. You could go on the net and get the specs of all the amps you plan to use. Obviously, it will be a different story for a quiet little jazz trio vs an 8-Marshall stack heavy metal band.

You could also add up all the 120 VAC fuse ratings. If you had a band that used 2 Twin Reverbs and 2 Deluxe Reverbs, you would have 3 + 3 (twins) and 2 + 2 (deluxes) which would be 10 amps. Amps times volts equals watts. To power such a band you would need 10 (amps) times 120 (volts) = 1200 watts.

Of course, there will be other things requiring power; the issue is if those are charcoal barbeque starters (which take a lot of current) or other large-current appliances. And then there's the issue of whether you wish to use this generator for other things when you are not playing in the band.

You probably want to double whatever number of watts you come up with. Dead minimum: 150% of what you come up with.

[PRR]

> charcoal barbeque starters

On a generator ? ? ?

I'm sure someone will try it. But 'tis silly many ways.

For 1,000 Watts in the charcoal lighter you need the equivalent of 5,000 watts of gasoline through the generator. (Best engine efficiency 40%, alternator 90%, at best-load which is near full-output. Since we typically won't be right-sized, real efficiency may be half.)

If the electricity comes from a well-run central generator, the Pollution may be less than lighter-fluid, or at least not right in your neighborhood. (Bad-burning lighter-fluid may be banned in smoggy towns, which is one reason electric ighters exist.)

But if you are out in the desert, just splash some gasoline on the charcoal. (Kids, do not try this at home!) If you plan ahead and think safe, a plumber's propane torch with a half-bottle of propane starts charcoal fairly quick and VERY clean (no Zippo-flavor burgers).

[RicharD]

5kW should be ample unless you're toting a Grateful Dead PA system.

[eleventeen]

I was just making a ridiculous example to illustrate the point the original question itself illustrated...that some do not consider the wattage devices use!

[Ritchie200]

Somewhat on topic....  Way back in 1974 Kiss came to St. Louis for a local rock radio station's annual kite fly in Forest Park (St. Louis' big city park, home of the 1904 Worlds Fair).  It was just an excuse for a party, but the station would bring in some great new acts, such as Rush, solo Nugent, Foghat, and the then unknown - Kiss.  It was an outdoor stage.  I am paraphrasing from the disc jockey who was put in charge - just because he happened to be in the wrong place at the wrong time.  He picked up Kiss and their manager from the hotel in an old smoking dodge van, had no AC, and with only the driver and a single passenger seat.  The station used it for running errands.  They were in full makeup and the manager was about 6'8" of muscle.  The manager wanted to know where the ^*&%ing limo was, and then sat in front.  The poor band was rolling around in the back with every turn.  They got to the park and 6 little generators were slowly dying with the local opening acts.  They were down to 1 for the pa and 1 for all the amps on stage (speaking of stacks of Marshalls).  The manager was furious saying they would not go on without more generators feeding the stage.  The station manager knew that the waiting crowd of about 15,000 were the biggest thing the band had ever seen, so he told the poor jock to go back and tell the manager to pack up in the van or to get their "a$$" on stage.  They played a full set with the volume varying from time to time. They also did two encores and the stage generator gave it up with the last dying chords.  He said the two generators were smoking throughout the performance and the manager was standing next to him boring holes into him with his eyes.  I was there and always wondered what was going on!  I wonder what voltages those poor amps were seeing!  Gene did an interview a few years ago with a local tv station and said he will never forget how well the crowd treated them at the Kite Fly and that it WAS the biggest show they had ever done to date.  No mention of the transportation accommodations!
Jim