Failure to properly ground the generator is the biggest safety issue with these machines, according to Nick Luciano, vice president, product development and compliance at MMD. “Almost no one does this on a regular basis,” he states. “Most rental companies do not even supply a grounding rod with their generator rentals.
“New generators are tested with a Hi-Pot dielectric test to check insulation strength,” he continues. “But with age, that insulation may break down and cause a short to the frame or covers on the generator, causing a shock hazard to the operator. Proper grounding will protect the operator from serious injuries or death.”
Some generators use an internally grounded neutral to the frame to ensure performance and personal protection. If in doubt, contact the manufacturer or dealer.
“If the portable unit is one of the smaller, handy, ‘pipe-frame’ or ‘hand carry’ models, they will most likely be fitted with voltage output receptacles, allowing the user easy interface, as well as protection by a ground fault current interrupting device, or GFCI,” says Jim Rose, director of sales, power equipment, at Multiquip.
For larger, trailer-mounted portable generators, however, the user is responsible for providing both an equipment ground, as well as a proper systems ground.
“The equipment ground is the conductor that runs from the generator ground to building service entrance main ground,” Rose explains. “The systems ground is the conductor that runs from the generator ground to an earth ground. The NEC (National Electrical Code) calls for one or two 8- to 10-ft. ground rods driven into the ground, with the intention of the ground rods’ net total resistance being no more than 25 Ohms. This will create a satisfactory low-impedance ground should a ground fault occur.”
More Safety Considerations
When selecting a generator, consider the available safety features. Many provide GFCI protection and covered outlets to minimize electrocution hazards. Some also feature additional guards, 110% fluid containment and emergency shutdown buttons and systems.
Other safety considerations for generator use include:
Proper ventilation. Because a generator uses a combustion engine, it gives off large amounts of carbon monoxide. As such, it’s important to ensure the generator is properly ventilated. Avoid running the generator indoors or in enclosed spaces of any kind, including garages, basements or crawl spaces. A well-ventilated room will not prevent the buildup of toxic gas.
When used outdoors, generators should be placed away from open-able windows and doors, as even prevailing winds can blow engine exhaust through the openings. In addition, a generator should always be placed with 3 to 4 ft. of clearance on all sides. This allows for air movement around the unit, which helps prevent carbon monoxide buildup.
Fuel-related risks. Under normal operating conditions, generators become quite hot. Pouring a flammable liquid on hot engine parts can cause the fuel to ignite. And while refueling a generator when it’s still warm — or worse, while it’s still running — might save a bit of time, it could put personnel in life-threatening situations. Make sure the generator is turned off and allowed to cool down completely before refueling.
Where the fuel is stored can also put operators in harm’s way. Flammable liquids should be handled and stored according to OSHA’s 29 CFR 1926.152 standard. This includes common-sense concepts such as not storing fuel indoors and storing fuel in properly labeled containers away from the generator and any other heat source. The heat from the generator can cause fuel vapors to ignite even in a sealed container.
Proper PPE. For those working near a generator, the noise level can be high enough to warrant hearing protection. Check the owner’s manual and manufacturer specifications to help determine if your model requires hearing protection. Keep in mind that wearing hearing protection when it might not be strictly required will not put anyone in danger and might help to protect you in the long run.
Wear other appropriate personal protection equipment (PPE), such as safety glasses, ear plugs, non-conductive gloves and shoes as required. Remove jewelry and wear tight-fitting clothing.