100 Foot Extension Cable + High Current = Voltage Drop – #0104

I ran into a problem that I should’ve caught earlier on, but figured it could make for an entertaining video. (and perhaps save someone else some time from avoiding this) I moved my air compressor when I rearranged my garage a year ago, but haven’t used the compressor enough for it to have turned on to refill since. (until today) It ran slowly for a couple seconds, then stopped, then popped the breaker. What the heck? SPOILER ALERT: It was the extension cord having too high of a voltage drop. Long cable + high current = voltage drop. I should’ve seen it coming!

If you ever can’t reach something with your air compressor, extend the air hose, not the power cable. You’re welcome 😉

P.S.: For anyone curious about the “half the power” comment, if it’s at 90 volts, that’s 11.25 amps (roughly 8 ohm load if we treat it as a resistive load to keep things simple), and 90 * 11.25 = 1012.5 watts. That’s almost half of the 1800 that the motor on the compressor is rated for, and apparently not nearly enough to run the compressor without stalling out. These are obviously some really rough ballpark numbers, so take this with a grain of salt. Inductive loads are a bit more tricky to do math on, especially with a dynamic load.

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