Do Portable Generators Need To Be Grounded

Do Portable Generators Need to be Grounded?

Portable generators have become an essential tool for many homeowners and outdoor enthusiasts. Whether you need backup power during a blackout or electricity on a camping trip, a portable generator can provide the necessary energy. However, one common question that arises is whether portable generators need to be grounded. In this article, we will explore the importance of grounding portable generators and the safety implications of not doing so.

Understanding Grounding

Before we delve into whether portable generators need to be grounded, let's first understand what grounding means. Grounding involves establishing a connection between the electrical system and the ground. This connection ensures that any excess electrical current is directed safely into the ground, protecting people and property from electric shock, fires, and damage to electrical equipment.

Grounding is typically achieved by connecting the generator's frame or a grounding wire to a grounding rod that is driven into the ground. By grounding the generator, you create a path for electrical faults to follow towards the ground, preventing potential hazards.

Grounding and Safety

One of the main reasons portable generators need to be grounded is safety. When a generator is not properly grounded, the risk of electrical shock and fire increases significantly. Grounding helps to minimize the danger by providing a safe route for electrical faults to dissipate.

Electrical shocks can occur when a person comes into contact with energized equipment or a faulty electrical system. By grounding the generator, you reduce the likelihood of electric shocks because any excess electrical currents are directed away from people and into the ground.

Additionally, grounding minimizes the risk of fires caused by electrical faults. When a fault occurs within the generator, the grounding mechanism channels the electrical current into the ground, preventing it from igniting nearby flammable materials.

National Electric Code (NEC) Requirements

The National Electric Code (NEC) provides guidelines and requirements for electrical installations in the United States. According to the NEC, portable generators must be grounded to ensure safe operation.

NEC 250.34 specifically states that portable generators should be grounded unless a listed exception applies. Grounding can be accomplished by connecting a grounding wire from the generator's frame to a grounding electrode system or an effectively grounded metal water pipe.

It's important to note that following the NEC requirements is not only a matter of safety but also a legal obligation. Non-compliance can result in code violations and potentially invalidate your insurance coverage.

Risk Factors to Consider

While grounding portable generators is important for safety, there are some risk factors to consider. Failure to properly ground a generator can lead to serious consequences, including electric shock and fires. Here are some key risk factors associated with not grounding a portable generator:

Electric Shock Hazards

When a generator is not grounded, there is an increased risk of electric shock for anyone in contact with the generator or connected equipment. The ungrounded generator may energize the equipment and create an electrical hazard that could result in injury or even death.

Voltage Feedback

Voltage feedback is another potential risk of not grounding a portable generator. Voltage feedback occurs when an ungrounded generator is connected to a building's electrical system, causing backfeeding of electrical energy into the utility lines. This poses a danger to utility workers who may be working on the power lines, as the backfed energy can result in electrocution.

Flammable Material Ignition

Failure to ground a generator may also lead to the ignition of flammable materials. Without proper grounding, electrical faults within the generator could produce sparks that ignite nearby combustible substances. This can result in fires that could have been prevented with proper grounding.

Damage to Electronics

Another risk of not grounding a portable generator is the potential damage to sensitive electronic equipment. Without grounding, electrical surges and other power irregularities can occur, causing damage to appliances, computers, and other devices connected to the generator.

Exceptions to Grounding

While portable generators generally need to be grounded for safety reasons, there are exceptions outlined in the NEC. These exceptions include:

Double-Insulated Generators

Double-insulated generators are designed to provide an extra layer of protection against electrical shock without the need for grounding. These generators have plastic or fiberglass housings to prevent any exposed metal parts from coming into contact with conductive surfaces.

Separately Derived Systems

A portable generator can be exempt from grounding if it operates as a separately derived system. In this case, the generator is isolated from the main electrical system through a transfer switch. The transfer switch ensures that the generator's neutral is not bonded to the system's neutral, allowing the generator to function independently.

It's essential to consult the NEC and local regulations to determine if any exceptions apply to your specific situation. In many cases, it is still recommended to ground portable generators for an added layer of safety.

How to Ground a Portable Generator

If your portable generator does not fall under the exceptions mentioned earlier, it should be properly grounded. Here are the steps to follow to ground a portable generator:

  1. Start by obtaining a grounding rod made of copper or galvanized steel. The rod should be at least 8 feet long and have a diameter of 5/8 inches.

  2. Identify a suitable location for the grounding rod near the generator. The rod should be placed at least 6 feet away from the generator and preferably driven into the ground until only a few inches are visible above the surface.

  3. Attach a copper grounding wire (No. 6 AWG copper wire is typically sufficient) to the generator's frame using a grounding bolt or other appropriate means. Ensure there is a clean metal-to-metal connection.

  1. Run the other end of the grounding wire to the grounding rod. Attach it securely to the rod using a grounding clamp.

  2. Finally, ensure that the grounding connection is tight and secure, and test the generator to ensure that it operates correctly.


In conclusion, portable generators should generally be grounded to ensure safety and minimize the risk of electrical shock, fires, and damage to electrical equipment. The National Electric Code mandates grounding unless the generator falls under specific exceptions.

While exceptions like double-insulated generators or separately derived systems exist, grounding is still best practice for most portable generators. Using proper grounding techniques allows fault currents to flow safely into the ground, protecting individuals, property, and electrical systems from harm.

Remember, safety is paramount when operating any electrical equipment, and understanding the importance of grounding portable generators is crucial for a safe and efficient operation.

Leave a Comment