You can't always get what you “watt”

(a watt is a unit of power)

Question: What do you get when you plug in a band and a roasting pan?
Answer: The correct answer is “a math challenge.”


As tempting as it might be, it is inadvisable and possibly dangerous to just start plugging things in because you have located an electrical outlet. The first thing we recommend that you should do, is a little simple math.

All electrical appliances, including crockpots, blow-dryers, roasting pans, and live bands (or DJ’s) consume electrical power in different yet definable (and usually published) quantities. 

Most venues and homes have electrical outlets. These outlets are often grouped together into circuits. For instance all the outlets in a room may be tied together into one circuit. If the electrician that installed your electric distribution system was thoughtful, you may even find notations inside your “breaker box” (you know that place that you look for when the power ceases to flow and everything stops working).

I’m writing to you (event planners, venue and property managers) because we need to have a power talk. 

All too often bands, DJ’s, and lighting technicians need more electrical power than is available to us. We know that it wasn’t your intention to overlook this detail, but nobody wants to hear me tell them that we can’t perform because there is an inadequate power supply, or have to reconfigure the room or site to accommodate electrical requirements.. We are often assured that there are outlets available, but just because you see an outlet doesn’t mean that it’s going to be located on a circuit that is sufficient to supply power for the entertainment. 

If you’ve read this far, we are going to offer you some tips on how you may estimate how many watts/amps are needed for your event? Thank goodness, this is a relatively easy question to answer. Nearly every device that is legal to use in the US has a UL rating (plate, tag, or sticker) attached to the device. On that plate/tag/sticker you will see information related to how much power that device requires. This will be expressed in either watts or amps. Voltage will also be indicated, but we will assume for the purposes of this article that your device will be plugged into a standard 120-volt outlet as found on walls throughout the US.

For instance a NESCO 18 QT. Roaster consumes 1425 watts and a FETCO Coffee Brewer (pictured) consumes 15.4-amps, which is too much for a 15-amp circuit. You’ll need to locate a 20-amp circuit if you wish to brew coffee.

So here’s where the math comes in. You need to write down the watts and/or amps indicated for each device that you want to plug into a circuit. Please notice, I did not say outlet, because oftentimes there will be several/many outlets in one circuit. 

The math is simple:

  • Amps = Watts / 120
  • Watts = 120 x Amps


So for argument sake, let’s say that you have a NESCO roaster pan. The tag indicates that it is a 1,425-watt device. So you would divide 1,425 by 120, giving you about 12 amps. Most circuits in the US will have either 15-amp or 20-amp circuits, so if you have a standard 15-amp circuit, you only have 3-amps of capacity to spare before you are in danger of overloading the circuit. Overloading can result in fires, melted wires, or the sudden failure of a device, or damage that may not immediately reveal itself, but will result in the premature failure, or operational concerns at some point.

Extension Cords

Extension cords are generally a big no-no, because few people take the time to calculate the loss of energy over the length of the cord. Depending upon wire size (generally expressed as gauge), extension cords waste a lot of energy (lost to resistance/heat) over distance.

For instance, if you plug your standard hardware-store style 16-gauge 50-foot long extension cord into a standard 120-volt outlet, at the end where you want to plug devices in, you have lost 10-volts to the cord, and you now only have 110-volts available for your devices. Most devices in the US will not safely operate on less than a 110-volt minimum. You would have to limit the total wattage of devices plugged into the end of this extension cord to 13.7-amps (1,600 watts), even if the circuit you plugged into was listed at 20-amps (Simply put you can't even have enough power needed for one fry-daddy, or one hair dryer, or one electric-roasting pan. You could maybe plug in a few lights and not overload the circuit.

Generators

Generators are an even bigger challenge, because you can’t usually trust the word of tool rental companies. They typically rent gear for worksite use, to power table saws, compressors, and drills. They do not understand the requirements of televisions, computers, and appliances with computer circuit boards. Even many of the people in this business don’t realize that cheap work-site generators produce a wave-form of electricity that can quickly toast the circuit boards in digital audio-mixers/speakers and computerized equipment. I was once attending an event where the sound system caught on fire because they had connected the wrong kind of generator to the system. They had no band. They had no lighting. The event was a failure, and it didn’t have to be. We’d love to help you correctly size your generator and help to assure you that the output from a generator is appropriate for your event.

One small food vendor shut down an entire multi-vendor festival when she plugged in a Fry Daddy Jr., because it was not included in the electrical plan, and the existing electrical load from all the other vendors was already operating very near the maximum limit available. She had to unplug her appliance and sit out the event because the event power grid did not support her only appliance, one little Fry Daddy Jr.

Hums, crackling, and buzzing

Mains power and generator power can both inject unwanted noises, such as hums and buzzes in a sound system. Usually these noises can be filtered out of a sound system using specialized electrical filtration equipment, but few venues, or event planners, are prepared to deal with these nuisances. These annoyances can really suck the joy out of an otherwise enjoyable event. 

Assuring You That It's Done Right

Calculating your energy needs and managing distribution that will pass an electrical inspection, is just one of the many services Freshwater Events provides.

Whenever possible Freshwater Events likes to do site-visits (assessments) in advance of our arrival, in order to be prepared for any challenges that greet us and develop an electrical plan to assure that when it comes to the services we provide: “it just works.” No drama. No problems.

Freshwater Events will always provide you with our specific power requirements in our contracts. Please always be sure to provide what we need. If you have questions, we'd love to hear from you in advance of the event.

Don't be this person


Don't be this person ... please