A portable generator is a gas or diesel-powered device which provides temporary electrical power. The engine turns a small turbine, which in turn creates usable electricity up to a certain level of wattage. Users can plug electrical appliance or tools directly into the generator’s sockets or the generator can be professionally wired into the sub-panel of a home. Many construction teams use a portable generator to power tools and lights at a remote site. Sports officials may also bring in one to aid in night play or to run an electronic timer/scoreboard. Most commonly, residents and businesses left without power after a weather event will use a portable generator to keep vital appliances operating. These devices usually have enough power to keep a freezer, refrigerator, television and some lights working. Because a portable generator uses a combustion engine to generate electricity, it must have several regulators on board. The engine must turn at 3600 rpm in order to generate the standard 60 Hz of alternating current. In order to control engine speed, a generator uses a ‘governor’ which mechanically keeps the engine from spinning too fast. A voltage regulator also keeps the output at 120 volts, which keeps electric motors from burning out.
Possible hazards from portable generator
- Shocks and electrocution from improper use of power or accidentally energizing other electrical systems.
- Carbon monoxide from a generator’s exhaust.
- Fires from improperly refueling a generator or inappropriately storing the fuel for a generator.
- Noise and vibration hazards
Shock and Electrocution
The electricity created by generators has the same hazards as normal utility-supplied electricity. It also has some additional hazards because generator users often bypass the safety devices (such as circuit breakers) that are built into electrical systems.
The following precautions are provided to reduce shock and electrocution hazards.
- Never attach a generator directly to the electrical system of a structure (home, office, trailer, etc.) unless a qualified electrician has properly installed the generator with a transfer switch. Attaching a generator directly to a building electrical system without a properly installed transfer switch can energize wiring systems for great distances. This creates a risk of electrocution for utility workers and others in the area.
- Always plug electrical appliances directly into the generator using the manufacturer’s supplied cords or extension cords that are grounded (3-pronged). Inspect the cords to make sure they are fully intact and not damaged, cut or abraded. Never use frayed or damaged extension cords. Ensure the cords are appropriately rated in watts or amps for the intended use. Do not use underrated cords—replace them with appropriately rated cords that use heavier gauge wires. Do not overload a generator; this can lead to overheating which can create a fire hazard.
- Use ground fault circuit interrupters (GFCIs), especially where electrical equipment is used in or around wet or damp locations. GFCIs shut off power when an electrical current is detected outside normal paths. GFCIs and extension cords with built-in GFCI protection can be purchased at hardware stores, do-it-yourself centers, and other locations that sell electrical equipment. Regardless of GFCI use, electrical equipment used in wet and damp locations must be listed and approved for those conditions.
- Make sure a generator is properly grounded and the grounding connections are tight. Consult the manufacturer’s instructions for proper grounding methods.
- Keep a generator dry; do not use it in the rain or wet conditions. If needed, protect a generator with a canopy. Never manipulate a generator’s electrical components if you are wet or standing in water.
- Do not use electrical equipment that has been submerged in water. Equipment must be thoroughly dried out and properly evaluated before using. Power off and do not use any electrical equipment that has strange odors or begins smoking.
Carbon Monoxide Poisoning
Carbon monoxide (CO) is a colorless, odorless, toxic gas. Many people have died from CO poisoning because their generator was not adequately ventilated. So remember:
- Never use a generator indoors or in enclosed spaces such as garages, crawlspaces, and basements. NOTE: Open windows and doors may NOT prevent CO from building up when a generator is located in an enclosed space.
- Make sure a generator has 3 to 4 feet of clear space on all sides and above it to ensure adequate ventilation.
- Do not use a generator outdoors if its placement near doors, windows, and vents could allow CO to enter and build up in occupied spaces.
- Generators become hot while running and remain hot for long periods after they are stopped. Generator fuels (gasoline, kerosene, etc.) can ignite when spilled on hot engine parts.
- Before refueling, shut down the generator and allow it to cool.
- Gasoline and other generator fuels should be stored and transported in approved containers that are properly designed and marked for their contents, and vented.
- Keep fuel containers away from flame producing and heat generating devices (such as the generator itself, water heaters, cigarettes, lighters, and matches). Do not smoke around fuel containers. Escaping vapors or vapors from spilled materials can travel long distances to ignition sources.
- Do not store generator fuels in your home. Store fuels away from living areas.
Noise and Vibration Hazards
- Generator engines vibrate and create noise. Excessive noise and vibration could cause hearing loss and fatigue that may affect job performance.
- Keep portable generators as far away as possible from work areas and gathering spaces.
- Wear hearing protection if this is not possible.
Safety Precautions of Portable Generator
General safety precautions
- Installation, repair and maintenance should always be in accordance with the manufacturer’s instructions and recommendations.
- Exhaust fumes emitted by generator sets contain poisonous gases like carbon monoxide that can be life threatening and result in death. Exhaust systems must be properly installed, adequate ventilation must be provided to ensure unobstructed flow of cooling and ventilating air, and emissions must be directed away from inhabited zones.
- The area around the generator must be clean and free of clutter and any combustible material that can be hazardous.
- The unit should not be opened or dismantled while it is functioning. Moving or hot parts should not be tampered with. Battery cables should be disconnected before proceeding to work on the generator to eliminate any possibility of an accidental start-up.
- All power voltage supplies should be turned off at the source while installing or servicing the generator.
- All electrical connections, such as wires, cables and terminals must be properly insulated and covered, and should not be touched with bare hands or while in contact with water. This is essential to prevent the occurrence of an electric shock.
- The frame of the generator and any external conducting parts should have proper grounding /earthling wiring. This should never be disconnected.
- Wiring, cable and cord sets must be of the recommended capacity.
Fire and Explosion precautions
- Smoking in the vicinity of the equipment can be fatal.
- Fuel or oil spills around the generator, leakages from the unit’s fuel system and fuel supply lines, and presence of combustible materials around the generator will pose a risk of an explosion.
- A fire extinguisher should be readily available. Use of extinguishers that operate on carbon tetra-chloride is strictly prohibited since the fumes are toxic and can deteriorate the insulation on the wiring of generators.
Regular Maintenance Schedules
Annual, semi-annual or quarterly maintenance schedules ought to be strictly followed to increase the reliability of the equipment. When the unit is inspected and exercised regularly, it continues to deliver consistent output as per expectations. Proactive maintenance also helps in detecting damages and defects at an early stage allowing preventive measures to be taken in a timely fashion.