Sizing extension cords

Retiredguy2 · Sep 17, 2016

I have never really thought about this issue prior to today...just purchased a new electric chain saw that draws 12 amps. I have almost never used any extension cord over 25 feet long to power a tool that uses 12-plus amps but it appears that to use my new saw I will need to use much more cord length. My household wiring uses 12 gauge that is about 45' long to supply the GFCI outdoor outlet I want to use to power the saw. Do I need to allow for that 45' distance within the house itself to determine the maximum extension cord length I can use? Thanks for any advice.

4570Man · Sep 17, 2016

I've got 10 gauge cord in my shop that I use to power the heavy draw stuff. My shop panel is powered by about 50 feet of 6 gauge. All of my 110 volt is wiring is 12 gauge and all of my 220 volt wiring is 10 gauge. The 10 gauge cord is 110 volt. If needed I've made cords for my 220 volt stuff. If you don't need something elegant making a cord will be your cheapest option. How far do you need to run. If it's more than 50 feet I'd scrap that idea and get a gas saw. The chainsaw will likely trip the GFIC breaker. You may need to run the cord through a door and plug into a non GFIC protected breaker.

Retiredguy2 · Sep 17, 2016

4570Man said:
I've got 10 gauge cord in my shop that I use to power the heavy draw stuff. My shop panel is powered by about 50 feet of 6 gauge. All of my 110 volt is wiring is 12 gauge and all of my 220 volt wiring is 10 gauge.

Glad you planned ahead but how does your illustration help answer my query?

4570Man · Sep 17, 2016

Retiredguy2 said:
Glad you planned ahead but how does your illustration help answer my query?

We'll I've edited my post about 3 times, but I don't factor in household wiring for a cord size.

GregbkH · Sep 17, 2016

Use a 12 or 14 gauge extension cord and you'll be fine.

4570Man · Sep 17, 2016

GregbkH said:
Use a 12 or 14 gauge extension cord and you'll be fine.

Unless he needs to go more than about 5 feet a 14 gauge is definitely too small. He didn't say how long he needs, but a 12 gauge is likely too small. My circular saw doesn't operate properly with a 50 foot 12 gauge cord.

EarPlug · Sep 17, 2016

16 Gauge Cords Any 16 gauge cord between 0 and 100 feet long will adequately handle tool loads up to 10 amps.
14 Gauge Cords Any 14 gauge cord between 0 and 50 feet long will adequately handle loads between 10 and 15 amps.
12 Gauge Cords If your tool load is between 10 and 15 amps and the length of the cord is 50 to 100 feet, you need a 12 gauge cord to safely power any tool.

Retiredguy2 · Sep 17, 2016

GregbkH said:
Use a 12 or 14 gauge extension cord and you'll be fine.[/QUOTE

Total distance to plug in my saw will be about 130-140 feet from the outlet which is 45 feet from the service panel itself. 12 amps draw on a 12 gauge cord for 175 feet? Would never try to use a 14 gauge cord for that purpose. I am sorry for not giving more clarification in the OP.

4570Man · Sep 17, 2016

You're going to need a minimum 10 gauge cord. I still wouldn't attempt it. The cost of such a cord alone makes it impractical. I would get a generator or a battery or gas powered saw.