Generators for hurricanes - safety and sizing basics
Run a portable generator only outdoors, at least 20 feet from doors, windows and vents, never in a garage, and put battery-powered carbon monoxide alarms in your home. Never plug it into a wall outlet; use outdoor-rated extension cords or a transfer switch installed by a licensed electrician. To size it, add the running watts of what you will power at once, then add the single largest starting surge.
Carbon monoxide kills quietly. You cannot see or smell it. If anyone feels sick, dizzy or weak while a generator is running, get everyone into fresh air immediately and call 911.
Safety rules
From the U.S. Consumer Product Safety Commission (CPSC generator safety alert) and the CDC (CDC):
- Outdoors only, 20 feet away. Run it at least 20 feet from doors, windows and vents that could let carbon monoxide inside.
- Never inside: not in the house, garage, crawlspace, shed or a similar space, even with fans running or doors and windows open.
- CO alarms. Install battery-operated carbon monoxide alarms, or plug-in alarms with battery backup, and test them. The CPSC lists alarms certified to UL 2034, IAS 6-96 or CSA 6.19.01.
- Keep it dry without moving it closer. In rain, set it on a dry surface under an open, canopy-like cover where water cannot pool; dry your hands before touching it.
- No backfeeding. Never plug a generator into a wall outlet. It can electrocute utility workers and neighbors.
- Cords. Use heavy-duty, outdoor-rated, three-prong extension cords rated above the total load, and check them for damage.
From LCEC, the Lee County Electric Cooperative (LCEC):
- To connect a generator to house wiring, have a licensed electrical contractor install a transfer switch. Do not connect at the breaker panel, meter or an outlet.
- Do not refuel while it is running, and avoid spilling fuel on hot parts.
- Store fuel in labeled, non-glass containers outside living areas, and not in a garage with a fuel-burning appliance.
- Don't overload it. Run only essential equipment within the generator's output rating.
Carbon monoxide symptoms
The Florida Department of Health lists fatigue, weakness, headache, shortness of breath, nausea, vomiting, confusion, lack of coordination and impaired vision, progressing to loss of consciousness. Get to fresh air right away. For severe cases call 911 or the Poison Information Center at 1-800-222-1222 (Florida Department of Health in Duval County).
Sizing basics
Generators are rated in watts. Many appliances draw extra power for a moment when they start (motors and compressors especially). A sizing worksheet hosted by the public utility Eugene Water & Electric Board describes this method (EWEB worksheet):
- List what you must run at the same time.
- Add up their running watts.
- Find the one item with the highest additional starting watts and add only that number.
- Choose a generator rated for at least both totals.
Example using the worksheet's approximate figures:
| Item | Running watts | Additional starting watts |
|---|---|---|
| Refrigerator/freezer | 700 | 2,200 |
| LED light bulb | 15 | none |
| Laptop | 60 | none |
| Total | 775 running | 775 + 2,200 = 2,975 starting |
The worksheet lists a 12,000 BTU window air conditioner at about 3,250 running and 3,950 additional starting watts, which shows how quickly cooling adds up. These are approximations: use the wattage on your own appliance labels, and confirm with an electrician or the manufacturer before you buy.
Before hurricane season
- Test-run the generator outdoors and check the oil.
- Buy CO alarms and fresh batteries. In Florida, portable generators and CO alarms are among the disaster supplies exempt from sales tax (Volusia County summary).
- Decide where it will sit, at least 20 feet from openings, before the storm, not in the dark after it.
- Add it to your hurricane preparedness checklist.
Frequently asked questions
- How far from the house should a generator be during a hurricane outage?
- At least 20 feet from doors, windows and vents, according to the CPSC and CDC. Never run it inside a home, garage, crawlspace or shed, even with doors open or fans running.
- Can I run a generator in my garage with the door open?
- No. The CPSC says never to use a generator inside homes, garages, crawlspaces, sheds or similar areas, even with fans or open doors and windows.
- Can I plug my generator into a wall outlet?
- No. That backfeeds power into the house wiring and the utility lines, which can electrocute utility workers and neighbors. Use extension cords rated for outdoor use, or have a licensed electrician install a transfer switch.
- What size generator do I need for a refrigerator?
- Check the appliance label. As an example, one utility sizing guide lists a refrigerator at about 700 running watts with 2,200 additional starting watts, so a refrigerator plus a light and a laptop needs roughly 775 running and 2,975 starting watts.
- What are the signs of carbon monoxide poisoning?
- The Florida Department of Health lists headache, fatigue, weakness, shortness of breath, nausea, vomiting, confusion and impaired vision. Get to fresh air right away and call 911 if symptoms are severe.