Looking at a remote sump pump. At a half horsepower the specs list 7 amps @ 115 volts. I need to use a hundred foot extension cord. The label on a 16 gauge rates it as 10 amps. Is that enough excess capacity?
I would not use less than a 12 gauge.
Quote from: Magicman on May 16, 2019, 05:31:41 PM
I would not use less than a 12 gauge.
As they said in the movie Jaws, your going to need a bigger cord. :D
there are charts that will tell at what length you need to jump up to a lager size wire. if the pump is gong to pump for a minute at a time, might be ok. If you are pumping out a collection of water, the cord may get hot, as well can be hard on the pump motor if you get a voltage drop, it will increase the amp pull. If this is for longer term or long periods of operation, i agree will all. Everyone should have a 100 foot 12 g cord anyway!!! at least that is what I would tell my wife... :D
There is also starting amp load to consider, being a pump it will be considered a hard or heavy start, so for a very short time it will pull a lot more amps.
A 12 is probably fine, personally I would go with a 10 to be sure. This way too should you need a heavy cord for a compressor or other device down the road you already own it.
10 g should pull 30 amps, but at distance it will be less.
Clearly, you couldn't go wrong with 4/0. Just to be safe. :D
When you consult a table that shows wire size and amperage capacity be careful to look at type of wire and insulation and if in conduit.
What gauge? Are you shootin or sawin? , just kidding.
great discussion. practically speaking, I would start with what you got, even the 16 until you find a good deal on a 12 g 100 foot cord. If it runs for a while, feel the cord (not while standing in water) and if it is noticeably warm, get the 12 g sooner rather than later. Is this a permanent solution or temp and or intermittent?
If you have enough of the smaller gauge wire you can double up the number of wires for more capacity.
Thanks everyone. Good advice for general scenarios. I used a wire size calculator from paige wire. Gives advice for both copper and aluminum