Home Generator Power Cords

Recently the CPSC put out a warning for consumers to immediately stop using Male-to-Male Extension Cords Sold on Amazon.com Due to Electrocution, Fire, and Carbon Monoxide Poisoning Hazards. And this isn’t some sort of Government over-reach, this is real! People are killed every year doing this.

Here’s a link to the original announcement


Honda 5000 Watt Generator Panel
My own 5000 Watt Home Generator Panel

Portable generator hookup seems easy. Just buy a double ended extension cord like the one the CPSC is warning about. Then plug that cord into one of your generator outlets and the other end into one of your house outlets – and you have power! But please read on…

The most obvious issue is what happens if that double ended extension cord gets tripped over and unplugged? You immediately have a live plug laying on the floor waiting to electrocute someone and if this happens at night, that live plug is laying on the floor in the dark! The second and less obvious issue is carbon monoxide poisoning. To prevent carbon monoxide poisoning you shouldn’t run your generator in your garage EVEN WITH YOUR GARAGE DOOR OPEN, on your semi-enclosed patio, or within 4 ft. of any door or window – open or closed. You can’t see Carbon Monoxide gas and it can easily seep through imperfectly sealed closed door and window gaskets.

But there are some additional problems and real dangers with this connection, starting with the extension cord itself. You can see that the standard outlets on my generator are marked with 20A which means that the outlets are rated for 20 Amps. But what about your extension cord wire size and why does it matter? It matters because most low cost extension cords bought on-line, or at Lowes / Home Depot are light duty. Light duty extension cord’s have small 16 Gauge wires that are only rated for 10 Amps. The next size up medium duty extension cords have 14 Gauge wires that are only rated for 15 Amps. And when you try to draw more current than an extension cord is rated for that extension cord becomes a small heater. Worse case the cord can melt and short out, possibly electrocuting someone or causing a fire. Best case the extension cord heater will cause a voltage drop and possibly damage some devices you have plugged into it.

Now lets assume that you have the correct wire size extension cord and it’s plugged into one of your house outlets. That’s great! You are 1/8th of the way there! But why are you only 1/8th of the way there? My generator is rated at 220V 5000 Watts and if you plugged your double ended extension cord into one of the 20A outlets you can only draw up to 20 Amps or 2200 Watts. This means that you can only use 44% of your generator’s power output.

But there’s more to consider! Houses in America are wired for 220V then that’s split in half for all of your 110V outlets. This means that half of your 220V goes to half of your outlets and the other half goes to the rest. And this also means that because you plugged into one of your 110V outlets, only half of your outlets will have power. There’s a 50/50 chance that your refrigerator has power and if your refrigerator has power and you have a separate freezer then there’s 50/50 chance that it also has power. The same goes for your TV and any lights or fans you might want to turn on.

So, what’s the best and safest answer?

The most expensive solution is to have an Electrician install a transfer switch or transfer interlock kit and a Generator Inlet Box. And then you just plug your 220V generator into the 4 wire generator inlet box with a 4 wire L14-30 male to female generator cord and switch power over with the transfer switch or interlock. The install should cost you from $500 to $2000 for hardware and labor. If you have a 5000 Watt generator like mine, your generator can’t produce enough power to run even one of your 220V items. You will need to turn off all of your 2 pole breakers that run your 220V items like your electric powered water heater, stove and AC / central heat you transfer power. But all of your 110V outlets will work and you should have enough power to run your refrigerator, freezer, TV, some lights and fans.

There are much lower cost solutions that are just as safe.

You can run individual extension cords from your generator to what you want you want to turn on. And that’s exactly what those four outlets in my generator are for. You can run an extension cord to your refrigerator, another to your freezer, another to run lights and your TV etc. Just make sure that each extension cord is rated for what it’s powering and the extension cords are long enough to place your generator away from any windows and doors.

Or assuming your generator has one, you can plug one 120V 30 Amp rated extension cord with a L5-30 plug and three 110V fan-out outlets on the other end into your generator. For reference the 110V 30A round plug looks like the one on the left side of my generator panel marked 30A. With this cord you would plug everything into the three outlets at the end of the cord. We make and sell a 4 outlet version in 25, 50 and 100 ft. lengths and in addition to our 4th outlet we include two 5A USB outlets for your USB devices. This way you don’t have to plug USB power supply into one of the 120V outlets to charge your cell phones and tablets.

25 Ft. 50 Ft. 100 Ft.

But even the solution above only uses 2/3 of your generator output. You only get 30 Amps at 110V. To use the full output of your generator you will need to use the L14-30 outlet shown on the right side of my generator panel. Most of the L14-30 cord sets sold on line split the 220V into four 110V outlets. We make and sell an 8 outlet version in 25, 50 and 100 ft. lengths and in addition to our 4 extra outlets we include two 5A USB outlets for your USB devices. This way you don’t have to plug USB power supply into one of the 120V outlets to charge your cell phones and tablets.

25 Ft. 50 Ft. 100 Ft.