More Power!

By on Fri, 08/28/2009 - 1:12pm

I was about half done and plugged in the monitor power amp which I had neglected to actually switch off before packing it into the truck. This meant that when I plugged it in it drew a lot of power very quickly and…

True story. I had a gig once in a sport’s bar where we were scheduled to go on right after the NBA playoff game ended. The bar was crowded and the patrons glues to the game as I went about setting up the system. I was about half done and plugged in the monitor power amp which I had neglected to actually switch off before packing it into the truck. This meant that when I plugged it in it drew a lot of power very quickly and…

All of the TVs in the bar went black as every eye in the place turned on me. That surge had been enough to blow the circuit breaker that ran the satellite TV system and it took more than 30 mins for someone to figure out how to turn it back on. Those were 30 very uncomfortable minutes that were caused by plugging in a small 120 watt amp. Four of the smallest PAR fixtures you can buy draw a combined 480 watts and a “tree” of four midsized Pars will draw 2000 watts.

Do the math.

No, really, do the math. (I know, you started playing music to get away from things like math class. But if you are carrying anything more than an acoustic guitar you need to know a few basics.) When it comes to figuring out how much power you need it is a very simple equation. W/V=A. Or, in English, Watts divided by Volts equal Amperes (or amps, the unit of measurement for electrical current). So, that four-lamp 2000 watt tree running on a 120 volt circuit will draw 16.6 amps all by itself. Add a couple of 100-watt guitar amps and you have maxed out one 20 amp circuit.

One last point: Electricity is serious business. NEVER take chances. If you don’t know what to do and how to do it safely, call an electrician. If you are laying in the burn unit of the hospital or in a coffin, that couple of hundred buck you saved by doing it yourself won’t seen like such a great investment.