Because of how much power an electric splitter requires to get through your tough logs, your extension cord can’t be too long or too thin. If it is, it won’t conduct enough power and you’ll experience a reduction in performance. But it is possible to balance length and gauge (thickness) and have plenty of power to split normally. (Remember that the thicker the cord, the lower the gauge, i.e. a 10-gauge cord is thicker than a 12-gauge cord.)
For the DR 5-Ton Electric Log Splitter and the DR Electric RapidFire Log Splitter, use a 12-gauge cord up to 25 feet, or a 10-gauge cord from 25 to 50 feet. We do not recommend using any cord over 50 feet. For other splitters, consult your owner’s manual.
Note also that log splitters usually work best when plugged in as close as possible to your junction box (or wherever your power enters the house/barn). Again, this ensures that your machine gets as much power as possible, and it isn’t diluted by traveling a long distance.