Safety with generators: CO, noise, and proper connection to the house.

How to use a generator safely in Portugal (without risks of CO and electric shock)

This article is for those searching for: "Is a home generator safe?" , " Can I use a generator in the garage? ", or " How to connect a generator at home ?".

Here's the clear answer: there are 3 main dangers — carbon monoxide (CO) , dangerous electrical connections , and fire/combustible materials . If you follow the right rules, you drastically reduce the risk.

1) Carbon monoxide (CO): the rule that saves lives

CO is an invisible and odorless gas. Health authorities are straightforward:

  • Never use a generator inside a house, garage, basement, storage room, or semi-enclosed spaces.

  • Always use outdoors , more than 20 feet (~6 meters) away from doors, windows, and openings/vents.

  • Use battery-powered/battery-backup CO detectors/alarms, ideally on multiple floors and near bedrooms.

The CPSC (USA) reinforces these same guidelines and warns that poisonings can happen quickly.

Golden rule: generator off + far away + exhaust pointed far away.

2) Rain and bad weather: beware of electric shock.

In inclement weather, follow the manufacturer's instructions. The CPSC indicates that there may be specific guidance regarding the risk of electric shock in rain/snow and mentions solutions such as appropriately rated non-combustible tents/shelters (depending on the model).

Important: Do not improvise coverings that could overheat/burn or block ventilation.

3) Connection to the house: never do “backfeeding” (it’s dangerous)

The most dangerous (and unfortunately common) way is to try to "power the house" by plugging the generator into an outlet. This can create backfeeding (current flowing back through the electrical system), putting neighbors and power technicians at risk, and increasing the risk of fire.

ESFI is clear: do not operate the generator without a transfer switch , because this isolates the grid and the generator and prevents backfeeding; and it must be installed by a qualified electrician.

Good, safe options (in general):

  1. Connect equipment directly to the generator (via generator outlets).

  2. If you want to power house circuits: a transfer switch / appropriate switching solution installed by a professional.

4) Fuel and fire: refueling the right way

The CPSC explicitly recommends:

  • Never refuel the generator while it is running.

  • Turn off and let cool before refueling.

ESFI also reinforces good practices: keep the generator dry, do not operate it when wet, and refuel when it is cold .

5) Noise in Portugal: avoid problems with neighbors

Generators make noise — and that can become a headache.

In Portugal, the General Noise Regulation (Decree-Law No. 9/2007) provides a framework for neighborhood noise, and there is practical reference to police intervention and measures to stop noise during the night.

Practical tips for reducing noise (without dangerous "hacks"):

  • Move the generator away from the wall (avoids "echo").

  • Use a stable and suitable anti-vibration base.

  • Choose models that focus on low noise (many inverter models advertise dB at 7 m).

6) Quick checklist: safe everyday use

  • Generator located outdoors , approximately 6 m+ from openings.

  • Operational CO alarms (test)

  • Never store in a garage/storage area, even with the doors open.

  • Never plug the device directly into the wall socket to power your home; use a transfer switch with a qualified electrician.

  • Do not refuel while hot/on; allow to cool down.

  • Caution: Rain and risk of electric shock; follow manufacturer's instructions.

  • Respect noise levels (especially at night).