Electrical question

[Silvercreek Farmer]

Any value in using a 10 gauge cord (25 ft) on an outlet wired with 12 gauge wire (20? ft) on a tool with a 14 gauge cord (6 ft)? The tools do seem to work better plugged directly into the wall vs using a 50 ft 12 gauge cord...

[Tazlaw]

Technically, yes there is a benefit. BUT, the benefit is minuscule at best. The longer and smaller (bigger number) the cord, the more resistance and thus the loss of power through heat there is. With those distances I really don’t see any significance in a bigger/shorter cord. But to answer the question correctly yes there is a benefit.

[rancher1913]

for that length ^^^^what he said^^^^^^

on longer runs it does make a noticeable difference and will help with voltage drop which starts getting critical at around 400 feet or so if I remember correctly

[dangitgriff]

The fatter the wire, the lower the resistance, the lower the hysteresis (voltage) loss, the lower the power loss at the tool/light/appliance for a given run length.
https://uploads.tapatalk-cdn.com/20200613/c510658691c7006b71e9e6280914faa5.jpg

In the chart above, a 10-gauge copper wire has 0.1 ohm of resistance per 100 feet, whereas a 12-gauge wire has .16 ohms and a 14-gauge wire has .25 ohms.
The 12-gauge wire has 62% of the current-carrying capacity of 10-gauge wire, whereas 14-gauge only has 40%.
Bottom line is this: the longer the run and/or higher the current load, the larger the extension cord gauge you should be using. If the extension cord gets hot to the touch under use, replace it with a higher-gauge cord.
R/Griff

[Silvercreek Farmer]

Found this on the web. Not too much difference with my situation. Those commonly found 100ft 14 gauge cords do come with a significant (6%+) voltage drop, though. https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=8.286&voltage=120&phase=ac&noofconductor=1&distance=25&distanceunit=feet&amperes=15&x=47&y=16
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[Silvercreek Farmer]

The fatter the wire, the lower the resistance, the lower the hysteresis (voltage) loss, the lower the power loss at the tool/light/appliance for a given run length.
https://uploads.tapatalk-cdn.com/20200613/c6bbfbb7cedd0ecc3fb1efd4d7723f1b.jpg
R/Griff

By that chart, I'd need a 6 gauge cord to run my circular saw 50 ft. Don't think so...could it be for 240v?

[dangitgriff]

By that chart, I'd need a 6 gauge cord to run my circular saw 50 ft. Don't think so...could it be for 240v?

Sorry about that, I saw that, and swapped the chart for a better one.
R/Griff

[jimlj]

Best to use the shortest cord possible on any tool. Best to use the largest (practical) cord possible on any tool.
My table saw runs great on a 25' #12 cord, but I have ran it on a 50' #14 cord. It struggles to start, and with hard use it would burn the motor in short order.
My air compressor don't like long cords at all. I took the 5' factory cord and replaced it with 15' of #12 cord and most of the time I don't need any other cord to use it.
Factory cords on tools are sized to make the tools work if plugged directly into an outlet properly sized. If you take the size of the factory cord wire and make a longer cord you likely will have problems.

[David2011]

By that chart, I'd need a 6 gauge cord to run my circular saw 50 ft. Don't think so...could it be for 240v?

Many tools can be wired for either 120 or 240 volts. The advantage of going 240 is the amp draw is cut in half. Wattage is the constant.

[MaryB]

Lower voltage to your tools motor means more heat generated in that motor because it is going to be working harder to do the same job. So tool life is also a concern. Smallest extension cord I use is 12 gauge, over 50 feet I swap to 10 gauge. That is on common hand tools. Bench tools I have short runs to get to power so it isn't a factor.