Safety is the most important thing to keep in mind when working with power tools and electrical equipment. When working outdoors, one of the most overlooked safety considerations is the choice of the extension cord used to bring the power out.
There are four things you need to consider when purchasing an extension cord for outdoor use:
Length
Gauge
Rating
Color
The Length
Outdoor cords are commonly sold in lengths of 25, 50, or 100 feet. The length you need to purchase will depend on the project you are working on, but where possible, use the shortest length that will get the job done. Excess cord laying around a work site presents a credible tripping hazard. For long distance jobs, extension cords can be joined together provided you use the proper gauge cords for the power load.
The Gauge
Once you have determined the overall length of the cord you need, need to determine the gauge of extension cord to use. Using an undersized cord is a fire hazard so please don’t do it! The most common gauges of outdoor extension cords are 12, 14, and 16. The smaller the gauge, the larger the wires are in the cord and the heavier the cord will be.
Larger wires allow you to deliver more power or to transmit it safely over a longer distance. In general, 16 gauge is safe to use up to 50 feet; 14 gauge up to 100 feet; and 12 gauge up to 150 feet. As always, follow the manufacturers recommendations and safety warning included when you purchase your cords.
The Rating
Extension cords are rated with alfa-numeric numbers based on the environment they were designed to operate in. You can find the rating stamped or printed on the outer cover. For outdoor cords, look for one of the following ratings: SW-A, SOW-A, STW-A, STOW-A, SJW-A, SJOW-A, SJTW-A, or SJTOW-A. The key rating letters to look for are W (Outdoor Use), J (Heavy Use), T (Vinyl Thermoplastic Cover), and O (Oil Resistant). Pick the combination that is right for your job.
The Color
Most people are familiar with the bright orange or red cords typically associated with outdoor use. These are ideal for applications where the cord will cross a lawn as the orange or red contrast nicely with green lawns in the Summer and brown lawns in the Winter. But outdoor cords come in a variety of colors. If you desire to hide or disguise your cord for a landscaping role, consider a brown or dark green cord to blend in.