Windstorms knock out power across Bellevue, Kirkland, Redmond, and the rest of the Eastside a few times most winters, and a portable generator is one of the more popular ways homeowners prepare for it. Used correctly, a generator is a genuinely useful piece of safety equipment. Used incorrectly, it's one of the more dangerous things in a home — not because generators are poorly made, but because of how people connect them to their house wiring and where they run them. Here's what actually matters.
The one mistake that causes real harm: backfeeding
The most dangerous thing people do with a portable generator is "backfeed" it into their home — running a cord from the generator into a wall outlet, usually with a cord that has male plugs on both ends (sometimes called a "suicide cord," which is an accurate name).
Backfeeding does two bad things at once. First, it can send power out through your home's wiring, through your electrical meter, and onto the utility lines outside your house — at the same time a lineworker may be out there trying to restore power, believing those lines are dead. That has killed utility workers. Second, without a transfer switch isolating your house from the utility feed, you have no way to guarantee your generator and the grid aren't both trying to push power into the same wires at once, which is a fire and equipment-damage risk even if the power is actually out.
The two safe ways to run a generator
- Direct cords to individual devices. For a smaller portable generator, running heavy-duty outdoor-rated extension cords straight from the generator to a refrigerator, a few lamps, a space heater, or a sump pump is safe and doesn't touch your home's wiring at all. This is the simplest option and needs no electrical work.
- A transfer switch. For running actual house circuits — your furnace blower, well pump, part of your lighting, the garage door — a transfer switch (manual/interlock or automatic) is installed at your electrical panel and physically prevents the utility and the generator from ever being connected at the same time. This is the only code-compliant way to connect a generator to your home's permanent wiring.
Why a transfer switch is worth the cost for most homes
A transfer switch means you're not running extension cords through windows or under doors during a storm, you can power hardwired equipment like a furnace blower or well pump that doesn't have a plug at all, and you get a system that's inspected and verified safe rather than improvised in the dark during an outage. If you're relying on a generator every winter rather than once in a rare emergency, a transfer switch generally pays for itself in convenience alone, separate from the safety case.
An automatic transfer switch paired with a standby generator goes a step further and switches over on its own within seconds of an outage, with no one needing to go outside in the storm to start anything. That's a bigger investment but removes the human step entirely.
Carbon monoxide is the other serious risk
Portable generators burn gasoline or propane and produce carbon monoxide (CO), a colorless, odorless gas that can incapacitate or kill people in an enclosed or partially enclosed space surprisingly fast.
Sizing it correctly
A generator that's too small will overload and shut down or damage sensitive electronics; one that's oversized is just money spent unnecessarily. Figuring out which circuits actually matter during an outage (heat, refrigeration, sump pump, some lighting) and sizing a generator and transfer switch around that "critical load" is a real calculation, not a guess — this is one of the things worth having an electrician do rather than eyeballing it from a chart at the hardware store.
What's typically required locally
Most jurisdictions on the Eastside require a permit and inspection for a permanently installed transfer switch, since it's a modification to your home's electrical system and interconnection with the utility feed. Requirements and the exact process vary by city, and your electrician will typically handle the permit as part of the job. This isn't something to skip — an uninspected, improperly installed transfer switch is exactly the kind of backfeeding risk described above, just hidden behind a wall instead of an obvious extension cord.
When to call a licensed electrician
Running cords directly from a generator to individual plug-in devices is something most homeowners can do safely on their own, as long as the cords are rated for outdoor use and the generator itself is running outside, away from the house.
Anything beyond that — a transfer switch, any connection point at your electrical panel, sizing a whole-home standby system, or wiring a generator inlet into your home's exterior — should always be done by a licensed electrician. This is panel-level work with real shock, fire, and backfeeding risk if it's done wrong, and it's also the kind of work that needs to be inspected to confirm it's actually safe before you rely on it during the next storm.
Want a professional opinion?
Call us any time, day or night, at (425) 615-5000, or book online. Written pricing before any work begins.
Related services: