How to Use a Portable Generator Safely

Safe generator use in an outage: placement at least 6 m (20 ft) from the house, CO alarms, fuel storage, grounding, cords and refuelling rules.

A portable generator can keep a fridge, a furnace or a sump pump running through a long outage. It can also kill you. Carbon monoxide from generator exhaust causes deaths every year after storms and ice events, usually when someone runs the machine too close to the house, in a garage or in a basement.

This guide covers the practical rules that official safety agencies in Canada and the US agree on.

Where to put it

Run the generator outdoors only, in a dry, open spot. Keep it at least 6 m (20 ft) from the house, with the exhaust pointing away from windows, doors, vents and neighbours' homes. Never run a generator in a garage, shed, carport, porch, basement or crawl space, even with the door open. Fans do not make it safe. Carbon monoxide builds up fast and can seep into the living space.

• Do not place it under a window or against a wall.
• Keep it on a level, stable surface.
• Protect it from rain and snow with a proper generator tent or canopy, leaving room for airflow. Never operate it under a tarp that traps exhaust.
• Keep children and pets away from it. The engine and exhaust get very hot.

Install carbon monoxide alarms

Put battery-powered or battery-backup CO alarms on every level of the home and near sleeping areas. Test them before you need them and replace their batteries on schedule. If an alarm sounds, or if anyone feels dizzy, has a headache or feels sick, go outside to fresh air and call emergency services. Do not go back in to check. See the CDC carbon monoxide page for symptoms and prevention.

Fuel storage and refuelling

• Store fuel only in approved, labelled containers, outdoors in a ventilated shed or similar, away from the house, pilot lights and ignition sources.
• Never store large amounts of fuel in the living space or attached garage.
• Turn the generator off and let it cool before refuelling. Gasoline spilled on a hot engine can ignite.
• Keep a fire extinguisher nearby and know how to use it.
• Check the manual for how long fuel should be stored, and for fuel stabilizer advice. Old fuel can gum up the carburetor.
• Check local rules on how much fuel you may keep at home.

Connecting appliances

You have two safe options. The first is to plug appliances directly into the generator using heavy-duty outdoor-rated extension cords. The second is to have a licensed electrician install a transfer switch or interlock kit. Our guide on transfer switches vs extension cords explains the trade-offs.

Never plug the generator into a wall outlet. This is called backfeeding. It can send electricity back through the grid and electrocute utility workers who think the line is dead. It can also overload wiring and start a fire.

Extension cords and loads

• Use cords rated for outdoor use and for the wattage of what you are plugging in. The cord's label gives its rating.
• Use the shortest cord that works. Long, thin cords overheat.
• Check cords for cuts and cracks. Replace damaged ones.
• Do not run cords under rugs or through doorways that pinch them.
• Add up the running watts and the startup surge of the devices you plan to use, and stay within the generator's rating. Start the biggest motor load first, then add smaller ones.

Grounding and wet conditions

Follow the manual on grounding. Some portable generators need a ground rod and others have a floating neutral and a bonded design. The label and instructions for your model tell you which. Never use a generator in rain or standing water, and never touch it with wet hands. Use ground fault circuit interrupter (GFCI) protection where the manual recommends it.

Running and maintenance

1. Read the manual before the first outage. Do a test run once or twice a year.
2. Check the oil level before each use.
3. Do not let it run out of oil or fuel while loaded. Running dry or low on oil damages the engine.
4. Turn off the appliances before starting or stopping the generator.
5. Rest the engine when the manual suggests, and refuel only after cooling.
6. Keep a log of run hours and service intervals.

For a broader outage plan, see how to prepare for a power outage.

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