2/9/00
Electric powered tools need an extension cord. Sizing the cord to the job is important. The recommended "gauge" sizes are list here. It is also recommended to go one size larger to account for start up load which is greater then running load. For those not familiar with wire sizing, the smaller the gauge number, the larger and heavier the wire. Hi amp motors combined with long extension cords will require the use of heavy wired cords. These can get awkward to handle. When deciding whether to purchase corded electric units rather than gas or battery, figure in the power demand of the corded units you are looking at and how long the extension cord will need to be. If the weight of the needed cord is more than you want to lug around, you should consider something else.
Most units will have an amp rating, if not, they'll have the watt and volt rating. Divide watts by volts and you have the amps. If your unit is rated at 110 volts and 1200 watts, divide 1200 by 110 and get 10.9 amps.
Amp Rating | 50 ft | 100 ft | 200 ft | 300 ft | 400 ft | 500 ft |
0-2 amps | 18 gauge | 18 gauge | 18 gauge | 16 gauge | 16 gauge | 14 gauge |
2-3 amps | 18 gauge | 18 gauge | 16 gauge | 14 gauge | 14 gauge | 12 gauge |
3-4 amps | 18 gauge | 18 gauge | 16 gauge | 14 gauge | 12 gauge | 12 gauge |
4-5 amps | 18 gauge | 18 gauge | 14 gauge | 12 gauge | 12 gauge | 10 gauge |
5-6 amps | 18 gauge | 16 gauge | 14 gauge | 12 gauge | 10 gauge | 10 gauge |
6-8 amps | 18 gauge | 16 gauge | 12 gauge | 10 gauge | 10 gauge | 8 gauge |
8-10 amps | 18 gauge | 14 gauge | 12 gauge | 10 gauge | 8 gauge | 8 gauge |
10-12 amps | 16 gauge | 14 gauge | 10 gauge | 8 gauge | 8 gauge | 6 gauge |
12-14 amps | 16 gauge | 12 gauge | 10 gauge | 8 gauge | 6 gauge | 6 gauge |
14-16 amps | 16 gauge | 12 gauge | 10 gauge | 8 gauge | 6 gauge | 6 gauge |
16-18 amps | 14 gauge | 12 gauge | 8 gauge | 8 gauge | 6 gauge | 4 gauge |