Installation
How to Connect a Generator to Your House Safely
Updated
Short answer
Connect a generator only through a transfer switch or a listed interlock with an inlet box, installed by an electrician. Never plug a generator into a wall outlet: it backfeeds utility lines and can kill line workers.
Why backfeeding is dangerous
Power from your generator can travel back through your service and transformer, energizing lines crews believe are dead.
Safe connection options
An inlet box with an interlock, a manual transfer switch, or an automatic transfer switch for a standby generator.
- Inlet + interlock: lower cost, manual
- Manual transfer switch: selected circuits
- Automatic transfer switch: standby systems
Placement
Run portable generators outdoors, at least 20 feet from doors and windows, never in a garage.
When to call an electrician
If anything is warm, smells hot, sparks or keeps failing after the simple checks above, stop and call. The electrician will test the circuit, find the cause and make it safe. Related service: Generator Installation.
Questions
Can I run my furnace on a portable generator?
Often yes, through a properly installed inlet and interlock or transfer switch, if the generator is sized for it.
Local help with generator installation
City guides with local permit offices, utilities and housing notes:
Editorial note: this guide is general information for US homes, not a substitute for an on-site assessment by a licensed electrician. Codes and permit rules vary by location.