How Do I Safely Connect a Portable Generator to My House?
From Solana Electrical, AZ ROC #341966
The short answer
There are only two safe ways to use a portable generator at home. Run outdoor-rated extension cords from the generator to the appliances you need, or have a licensed electrician install a transfer switch or interlock so the generator can feed chosen circuits. Never plug a generator into a wall outlet.
Never plug it into a wall outlet
Some people use a cord with a plug on both ends to push generator power back through a wall outlet. This is called backfeeding. The CPSC warns that it is extremely dangerous. It can send power out to the utility lines and put line workers and neighbors at risk of electrocution, and it bypasses some of the protection built into your home’s wiring.
Those double-ended cords are sometimes sold online. Do not buy or use one.
Option one: extension cords
For a few appliances, the simplest safe setup is extension cords.
Use heavy-duty cords made for outdoor use.
Check that each cord is rated for more than the total wattage of what is plugged into it.
Look over each cord for cuts or worn spots before you use it.
Do not pinch a cord in a door or window.
Option two: a transfer switch or interlock
If you want the generator to run a few household circuits, such as the refrigerator, some lights and a medical device, you need a transfer switch or an interlock at your panel. Both make it impossible for generator power and utility power to be connected at the same time. You plug the generator into an inlet outside, then switch over.
This is panel work. It should be done by a licensed electrician, usually with a permit. Our guide on transfer switches and interlocks explains the difference.
Where the generator goes
Generator exhaust contains carbon monoxide, which you cannot see or smell. The CPSC says to run a portable generator outside only, at least 20 feet from the house, with the exhaust pointed away from doors, windows and vents. Never run it in a garage, carport or porch, even with the door open. Keep it dry, and dry your hands before you touch it.
Have working CO alarms in the home, with battery backup, and test them before you need the generator.
Talk to a real person
Call (602) 999-2770 and a person answers, any hour. Tell us what you want the generator to run. We will tell you plainly what it takes, and you will hear the price before anyone drives out. Our work carries a two-year warranty on labor and material.
If a CO alarm sounds or anyone feels dizzy or sick while a generator runs, get outside to fresh air and call 911.
Common questions
Can I plug my generator into the dryer outlet?
No. Any outlet used to push power back into the house is backfeeding, and it is dangerous. Use extension cords or a transfer switch or interlock.
Is an interlock as safe as a transfer switch?
When installed by a licensed electrician on a panel it is made for, both keep generator and utility power apart. Which fits depends on your panel.
Can I run the generator in my garage with the door open?
No. Carbon monoxide can still build up. Run it outside, at least 20 feet from the house.
