Live Sound & Amplifiers - Generator Watts Vs Acoustic Watts?

[bassmantam]

I've recently been asked can I supply my bass stack and PA for a small outdoor event and I have a few concerns over this.

I would be putting my GK400B onstage and adding my Mackie rig (2x450 + 2x1200 subs) and a peavey escort 3000 for foldback. total RMS output is around 2.5K. Added to that by others will be 2 x fender combos (100w I think) 2 x stage boxes for a keyboard and a standard 5 kit. no lights.

The event is going to use a Honda ecm4000 generator and I'm concerned that may be underpowered. I think the generator has a peak output of 3.8K and a continuous output of 3.6K and I've been reading that valve amps in particular can actually draw a load up to 3 times the stated output and tend to have a pf of 0.3 and transistorized amps up to twice the power. everything is to be run from the one generator which as far as I know has never been used for this purpose before.

Can an underpowered generator damage my equipment?

Is there an easy way to check it will work safely before I put my gear up?

 

[mmon77]

All your gear should have power requirements on the back panel or in the manual. Add it up and see what you get. These are usually the max power requirements. I would guess your gear alone would come close to the total wattage that generator can handle.

An underpowered generator will more than likely shut down to protect itself. This could cause brownouts which can certainly damage your gear. The only way to know that it can safely power everything is to add up the total wattage of all the gear and make sure it's comfortably within the range that the generator can supply.

Edit: To the title of your thread- You can't really rely on the output (Audio) watts to determine the power requirements of the amps. It depends to much on the type of amp (tube vs solid state) and amp class (A, AB, D, etc).

 

[WayneP]

What mmon77 said:

The only way to know that it can safely power everything is to add up the total wattage of all the gear and make sure it's comfortably within the range that the generator can supply.

The key is “comfortably within range.” I’m no expert but I’d say your generator should have at least 30-50% more capacity than your equipment requires.

Regards,
Wayne A. Pflughaupt

Administrator, Pedulla Club #45
Administrator, Tobias Club #133
Fretless Club #943
Big Cabs Club #23
My Rig: Stage and FOH Friendly
My Basses

 

[mmon77]

Branch circuits in homes are supposed to only be loaded to 80% of their capacity, so I would say a 20% margin is a "safe" reserve capacity. That being said, I'd feel more comfortable with 30-50% as stated above.