3500/ 4000 Watt Generator Cables Question?

I don't think #10 is necessary for the 240v connection, 4000 watts is 16.6 amps, #10 is rated for twice that.

Get the cord that the amperage rating on the package that matches your load. The manufacturer knows what type of wire they used and know what size is needed for the load to satisfy UL.

So the max load you may need? 4000 is a peak number, should only expect to furnish that power when subjected to inrush of inductive (motor) loads. so really 3500 watts is the number you should deal with.

But peak or non peak considerations aside, since the code deals with amps, let's convert that generator rating to amps, at 240v the generator would be a 14.6/16.66 amp generator.

So for wire size most people quote NEC 310.16, which is for building wire, but there are other sections, like Article 400, "Flexible Cords and Cables". This probably the section the cord maker uses. Table 400.5(A) says #14 is good for 18 amps with two current carrying conductors, that size more than covers the max amps at 240v. If connecting a 4 wire cable to a home panel only two wires will actually carry current.

You may need to consider voltage drop, using more than 100ft. of #14 will cause voltage drop that may adversely effect performance of motor loads that will drive the amperage up.

Champion 4000 Watt Generator

I'm no expert on this, but there are 2 things to look at with this, First the technical aspect: Putting on a cable with a lower rating is not the safe way to go and will heat up the cable. Melting it is the wild card factor, maybe, maybe not.

Second: It is my experience that a generator is usually taxed to its limit when used for civilian purposes. This is a social thing: people hear the engine or see the house lights come on, then they assume everything is back to normal (when it is NOT).

The bottom line: Be safe, spend a little extra now for the right cable, then have some fun turning on things until the breaker kicks out. THEN you'll truly know how much juice you're pulling. Take notes too, so that you can tell how many things you can have.

Use #10 - 4 conductor type SJ rubber covered cord and a correct twist-lock connector on the 30 amp outlet. Buy a #12 - 4 conductor cord for the 20 amp outlet. The length is up to you.

Use minimum 10 gauge wire for the 30 amp connection and 12 gauge for the 20 amp connection. Home Depot guy won't pay for your fried equipment. If it says 30 amp then use 30amp.

It is okay as long as you don't attempt to draw 30 amps through a cable rated for 20 amps.

For most usage, it would be unusual to draw more than 20 amps.

the other people are right. if ya do it the home depot way ya might melt the cords when your pulling a full load