Can you run your house on a portable generator?

Yes, for part of your house, and a portable generator is a perfectly reasonable answer to an outage that lasts a day or two. Plenty of households in Santa Clara County get through shutoffs with one and nothing goes wrong.

The machine is not the hazard. Two specific mistakes are, and they are worth keeping separate in your head because the fix for each is different.

Where you put it decides whether it poisons your household. Carbon monoxide from portable generators kills roughly 85 people a year in the United States, and the Consumer Product Safety Commission has recorded at least 1,332 deaths involving them since 2004. More than 80 percent happen at home. The most common reasons people were running one in those fatal cases were weather outages and power shutoffs, which is to say: exactly the situation you are in.

How you connect it decides whether it endangers somebody working down the street. That one has nothing to do with your own safety, which is precisely why it gets skipped.

Get both right and a portable is a good tool. The rest of this page is what getting them right actually means.

The second mistake is connecting the generator to the house by running a cord from it into a wall outlet or the dryer outlet. It is sometimes described as a shortcut. It is not a shortcut, it is a different thing entirely.

Power fed in that way travels backwards through your branch circuit, into your panel, through the main breaker if it is closed, and out onto the utility line. The crew restoring your neighborhood is working on a line they have every reason to believe is dead. Your generator is what makes it live. This is a well documented cause of serious injury and death among line workers, and it is entirely preventable.

There is a second hazard pointed the other way. A cord with plug ends on both sides has exposed live pins at whichever end is not yet connected. In the dark, during a storm, that is in your own hands.

There are two legitimate ways to power house circuits from a portable, and both work on the same principle: making it physically impossible for your generator and the utility to be connected at the same instant.

A transfer switch moves a defined set of circuits from utility to generator, and cannot do both at once. Because it feeds specific circuits, it also prevents you from accidentally loading the generator with the range and the dryer.

An interlock is a mechanical plate on your panel that will not allow the main breaker and the generator breaker to be on together. It costs less, it works, and it has to be listed for and matched to your exact panel. It also leaves load management to you, because it energizes the whole panel and expects you to choose what to switch on.

Both need an outdoor inlet so that the cord connects to something fixed rather than to an outlet, and both are panel work, which means permitted and inspected.

Two questions settle it. Placement comes first, because carbon monoxide is the one that reaches you and it applies no matter how the power gets indoors.

Expectations cause more disappointment here than the equipment does. What a portable can reach depends first on how it is connected, and only then on its capacity.

On extension cords, you get things you can plug in: a refrigerator, a freezer, lamps, phone and laptop charging, the modem and router, often a window air conditioner. That covers most of what makes an outage bearable. What it cannot reach is anything hardwired, and that is the whole category people actually miss. A furnace is hardwired. So is a well pump, a sump pump, and most central air conditioning. No cord will ever get to them.

Through an inlet and an interlock or transfer switch, those circuits come into range, which is the real reason to install one. Capacity still governs, though, and a portable is not going to carry an electric range, an electric water heater, central air conditioning, or EV charging no matter how it is wired. Choosing what to run, and running it a few things at a time, is part of operating one.

Sizing is worth a real conversation rather than a rule of thumb, because it depends on which specific loads you are unwilling to lose and how they start. Motors draw far more on startup than while running, which is what catches people out when the well pump kicks in and everything else drops.

A portable is the right tool for the occasional outage. There are four signs it has stopped being the right tool for yours, and none of them are about the machine.

1. 1

   You are doing this more than once a year

   A portable earns its keep for the occasional storm. Once hauling it out, fueling it, and running cords has become an annual or seasonal routine, the arithmetic changes, and so does the risk, because familiarity is what makes people start cutting corners on placement.

2. 2

   Something in the house cannot simply stop

   Medical equipment, a well pump, a sump pump, a home office that has to stay online, a freezer with real value in it. Anything hardwired is out of reach of extension cords entirely, which is usually the point where people start improvising dangerous connections.

3. 3

   Nobody is reliably home to start it

   A portable requires a person to notice the outage, go outside, start it, and connect it. If outages arrive while the house is empty or while everyone is asleep, the thing you actually need is equipment that transfers on its own.

4. 4

   You have already improvised once

   If a cord has ever gone into a wall outlet, or a breaker has been switched while a generator was connected, the setup has already been past the line once. That is worth fixing properly rather than resolving to be more careful next time.