Generator Safety Guide | PES Supply
Generator Safety Guide
Essential safety rules for operating portable and standby generators
Critical Safety Warning: Carbon monoxide (CO) from portable generators kills over 70 people per year in the US. Always operate generators outdoors, at least 20 feet from any building, with exhaust pointing away from doors and windows.
Carbon Monoxide Safety
| CO Concentration | Exposure Time | Symptoms |
|---|---|---|
| 50 ppm | 8 hours | Maximum safe exposure (OSHA) |
| 200 ppm | 2-3 hours | Headache, fatigue, nausea |
| 400 ppm | 1-2 hours | Severe headache, dizziness |
| 800 ppm | 45 minutes | Confusion, collapse |
| 1,600 ppm | 20 minutes | Unconsciousness, death risk |
| 3,200 ppm | 5-10 minutes | Death |
A typical portable generator produces 500-4,000 ppm of CO at the exhaust. Always maintain minimum distance:
| Generator Size | Min Distance | CO Output |
|---|---|---|
| 2,000W inverter | 20 ft from building | ~500 ppm at exhaust |
| 7,500W portable | 20+ ft, exhaust away | ~2,000 ppm at exhaust |
| 15,000W+ portable | 25+ ft minimum | ~3,000+ ppm at exhaust |
| Standby (permanent) | Installed per code | Exhaust vented properly |
Electrical Safety
- Always use a transfer switch — never backfeed through a dryer outlet
- Use GFCI-protected outlets — required on all portable generators since 2015
- Ground the generator — per NEC 250.34 (ground rod or building ground)
- Use outdoor-rated extension cords — 12 AWG minimum for 20A circuits
- Keep cords dry — use cord covers in wet weather
- Don't overload — calculate total load before plugging in
Fuel Safety
| Fuel Type | Storage Limit | Shelf Life | Safety Notes |
|---|---|---|---|
| Gasoline | 25 gal (residential) | 3-6 months (with stabilizer) | Never refill hot/running generator |
| Propane (LP) | Unlimited (tanks) | Indefinite | Store tanks upright, outdoors |
| Natural Gas | Piped (no storage) | N/A | Have gas leak detector |
| Diesel | Unlimited (tanks) | 6-12 months | Add biocide for long storage |
Operating Rules
- Start generator before connecting loads
- Connect loads one at a time (avoid surge)
- Never refuel while running — let cool 10 minutes
- Keep children and pets away
- Install battery-operated CO detectors in sleeping areas
- Turn off and unplug all loads before shutting down generator
- Run generator dry of fuel before storage (gasoline models)
- Check oil level before each use
- Never operate in rain without generator tent/canopy
- Keep fire extinguisher nearby (Class B for fuel fires)
CO Shield Technology (2015+)
Modern portable generators include CO Shield (carbon monoxide auto-shutoff). This safety feature detects dangerous CO levels and shuts off the engine. Look for models with:
- ANSI/PGMA G300-2018 certification
- CO sensor with auto-shutoff at 400 ppm
- Lifetime sensor warranty