Generator transfer switches
The transfer switch is what makes a generator safe to connect to your house. Here's how the options differ.
A transfer switch separates your home's wiring from the utility lines before generator power is connected. NC State Extension explains that the switch prevents the generator from back-feeding electricity into the power lines, a hazard for line crews working to restore service, and it also protects the generator when utility power comes back.
Automatic or manual?
- Automatic transfer switches come with standby generators. They sense the outage, start the generator and switch the house over without anyone touching them.
- Manual transfer switches are common with portable generators. You start the generator outdoors, plug it into an inlet box on the house, and flip the switch yourself.
- Interlock kits are a lower-cost option on some panels that mechanically prevent the main breaker and a generator breaker from being on at the same time. Whether one is allowed depends on the panel and the inspector.
Whole-house or subpanel?
A service-rated switch installed at the meter can carry the entire house. A smaller switch can feed a subpanel with only the circuits you choose. The right choice depends on the generator size, the age and layout of your panel, and how much of the house you want running.
Never backfeed through an outlet
Plugging a generator into a dryer or wall outlet with a homemade double-ended cord is dangerous to you and to utility workers, and it can damage the generator when power returns. If you own a portable generator, a properly installed inlet and transfer switch is the safe way to use it with house circuits.
Who can install one?
This is electrical work that needs a permit and, unless you're the owner doing work on your own home that isn't for sale or rent, a contractor licensed by the North Carolina State Board of Examiners of Electrical Contractors.
The installer prices the job after learning about your house, your electrical panel and your fuel supply, and usually after a site visit. We don't quote prices, and any figure given over the phone is only a rough starting point until someone has seen the property.
Where we connect you with help
- Wilmington
- Carolina Beach and Kure Beach
- Leland and northern Brunswick County
- Hampstead and Pender County
Common questions
Can I add a transfer switch for my portable generator?
Yes. A manual transfer switch or, where allowed, an interlock kit with an outdoor inlet lets you power chosen circuits safely. It needs a permit and proper installation.
Do I need a new panel to add a transfer switch?
Not always. Older or full panels sometimes need upgrades, and the installer will tell you after looking at yours.
Related services
More background: Wilmington standby generator guide.
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