A portable generator can help during an outage, but using it incorrectly can expose your household and others to carbon monoxide, electric shock and fire.
The most important rules are straightforward: operate fuel-burning portable generators outdoors, keep exhaust away from buildings, use suitable electrical connections, and shut down and cool the engine before refueling.
This guide focuses on portable fuel-burning generators. Permanently installed standby units require a site-specific professional installation. Battery power stations have different operating requirements and should not be treated as interchangeable with engine generators.
1. Choose a Safe Location Before an Outage
The U.S. Consumer Product Safety Commission advises operating portable generators at least 20 feet from homes and buildings, with exhaust directed away from windows, doors and vents.
Never run one inside a home, garage, basement, crawlspace, shed or another enclosed area—even with doors and windows open.
Consider neighboring properties and air intakes as well as your own. If your property cannot accommodate suitable placement, choose another backup approach.
Our generator placement and noise guide explores these site constraints.
2. Use Carbon Monoxide Alarms
Install and maintain battery-operated or battery-backed carbon monoxide alarms on every level and outside sleeping areas. Follow their installation instructions and test them regularly.
A generator’s automatic carbon monoxide shutoff is an additional safeguard, not permission to operate it indoors or near openings.
If a CO alarm sounds, get everyone outside immediately and call emergency services from safety. Do not remain inside to investigate or stop to switch off equipment. Do not re-enter until emergency responders say it is safe.
3. Plan the Electrical Connection
There are two different arrangements to consider:
| Arrangement | Planning requirement |
|---|---|
| Supplying suitable appliances directly | Correct outlets, compatible equipment and properly rated cords |
| Supplying fixed household circuits | Professionally selected and installed transfer equipment and connections |
Never supply household wiring by plugging a generator into an ordinary wall outlet. This can energize wiring unexpectedly and endanger utility workers, occupants and others.
Do not use a cord with a male plug at both ends. Switching off the main breaker is not a substitute for an approved transfer arrangement.
Have a qualified electrician assess any proposed building connection. Read our guide to connecting backup power to a home before making installation decisions.
4. Inspect Cords and Stay Within Ratings
Use cords suitable for the intended outdoor conditions and connected load. Inspect plugs, insulation and connections before use.
Remove damaged cords from service. Do not remove grounding pins, bypass protection or improvise adapters to make incompatible outlets fit.
Keep cords away from hot surfaces, sharp edges and locations where doors or vehicles could damage them. Arrange them to reduce trip hazards.
The generator, outlet and cord each have limits. Staying below the generator’s overall watt rating does not guarantee that an individual outlet or cord is adequately rated.
Start with a backup power sizing worksheet to identify what you intend to operate.
5. Treat Rain and Standing Water as Electrical Hazards
Do not operate electrical equipment while standing in water or handle connections with wet hands.
Follow the generator manufacturer’s instructions for wet-weather operation. Weather protection must not trap exhaust or restrict cooling.
Moving a generator into a garage to keep it dry is not a safe solution. Neither is enclosing it in a homemade box without a suitable engineered design.
If you cannot operate the equipment within its specified conditions, stop using it until a safe arrangement is available.
6. Shut Down and Cool Before Refueling
Never add fuel while the engine is running or hot. Spilled fuel can ignite on hot components.
Follow the manufacturer’s shutdown procedure, allow the equipment to cool, and use the specified fuel. Keep smoking, flames and other ignition sources away.
Use approved fuel containers and a storage location permitted by local requirements. Do not store fuel in living spaces or where vapors could reach ignition sources.
Plan fuel availability before an outage rather than improvising during one. Our generator fuel and runtime guide covers the planning questions.
7. Prepare a Manageable Load Plan
Decide which appliances matter most and how you will use them.
A written operating schedule helps prevent household members from adding unexpected loads. It also makes it easier to identify equipment that can wait until normal power returns.
Our guide to reducing backup power demand can help you prioritize.
Prepare an alternative for periods when the generator cannot run—for example, during refueling or conditions outside its operating limits. A properly selected battery system may support certain loads during those periods, but any combined arrangement requires compatible equipment.
See DIY battery backup for home for planning boundaries and component considerations.
8. Make Maintenance Part of Readiness
Keep the exact model’s manual available and follow its inspection, servicing and storage instructions.
Maintain a record of service dates, operating hours and unresolved problems. A generator stored for months should not be assumed ready simply because it worked during the previous outage.
Our backup generator maintenance checklist provides a framework for organizing the manufacturer’s requirements.
For the broader household plan, use the power outage preparation checklist.
A Household Generator Safety Plan
Before the next outage, write down:
- The intended outdoor operating location.
- The equipment and connections that have been approved for use.
- Which appliances will run and which will remain off.
- Who knows the manufacturer’s starting and shutdown procedures.
- How refueling and cooling periods will be managed.
- Where the manual and maintenance records are kept.
- What the household will do if the generator is unavailable.
Share the plan with everyone who may operate the equipment. Do not rely on one person remembering every instruction during a stressful outage.
Frequently Asked Questions
Can I run a generator in a garage with the door open?
No. An open garage door does not make indoor generator operation safe.
Is a carbon monoxide shutoff enough protection?
No. It supplements safe operation; it does not replace outdoor placement, suitable separation from buildings or working household alarms.
Can I use a longer cord to reach a safer location?
The cord must be suitable for its length, connected load and operating conditions. Ask the manufacturer or a qualified electrician to confirm the arrangement rather than selecting a cord solely because it reaches.
Does every generator need a separate ground rod?
Grounding and bonding requirements depend on the generator and how it supplies power. Follow the manual and have a qualified electrician assess the arrangement. Do not add or remove bonds based on generic online instructions.
Make Safety Part of the Purchase Decision
Before buying a generator, confirm that your property can accommodate it and that you can arrange suitable connections, fuel storage and maintenance.
If those requirements cannot be met, reconsider the proposed setup. A backup plan is useful only when the equipment can be operated safely.
Resources
- CPSC — Generator, Carbon Monoxide and Fire Hazards
- OSHA — Using Portable Generators Safely
- CPSC — Portable Generator Hazards
- OSHA — Grounding Requirements for Portable Generators
This article provides general safety information, not an installation design. Follow the instructions for your exact equipment and applicable local requirements. Use qualified professionals for electrical installation and unresolved technical questions.