How to Ground a Generator? Do I Need To?

Last Updated: August 8, 2022
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Though portable generators are fairly safe in comparison to other motorized tools, there are still important safety precautions to bear in mind if you wish to ground one. Finding out if your generator has to be grounded and then figuring out how to accomplish so are two of the most critical steps in generator safety even if you are running a battery operated indoor generator.

Does the portable generator need to be grounded? – It is determined by the application. You don’t need a ground rod if you’re merely utilizing extension cables (If you have a portable bonded neutral generator)

You must connect your generator to a ground rod when connecting to an electrical panel (residential electrical system, transfer switch, etc.). Ground rods must be driven into the ground and then linked to the generator’s ground lug via a ground wire. The rod must be inserted at least 8 feet into the earth.

We highly advise that you examine and follow all relevant federal, state, and municipal grounding requirements.

What Is Grounding?

The linking of the electrical system to the ground is known as grounding. The NEC classifies ground as “the earth” and specifies that grounded electrical systems must be connected to earth in such a way that the voltage caused by thunder, line spikes, or unintended contact with greater lines is limited, and the voltage to earth is stabilized during normal operating conditions.

Importance of Proper Grounding and Bonding for Electrical Systems

When electricity flows through a series of wires, it is always looking for a way to dissipate energy by returning to a ground. Electricity passes through “hot” wires to a series of neutral wires in a typical electrical system, such as your generator’s.

However, if the regular electrical circuit is disrupted, electricity will flow along the path of least resistance. If your generator isn’t grounded, the path of least resistance may enable electricity to go where it shouldn’t, resulting in electrocution, fire, or other hazardous scenarios.

Grounding creates a low-resistance backup path for electricity to flow. Because many electrical systems’ backup paths run directly into the ground, where they might offer relatively minimal risk, the term “grounding” is adopted.

Bonding Vs Grounding

Generators and other electrical systems have unique bonding and grounding requirements. The connection between an electric circuit or equipment and reference ground, which includes the generator’s frame, is referred to as grounding. The purposeful connection between the neutral grounded circuit conductor and the portable generator’s frame, is known as bonding.

As a result, proper neutral conductor bonding to the generator’s frame is also a problem for the equipment’s safe operation. The proper bonding of a power receptacle’s neutral terminal may be validated by testing by a professional electrician with the appropriate equipment, and the resistance should measure near zero.

Grounding Requirements for generator

Article 250 of the NEC specifies the grounding requirements for generators linked through transfer switches.

If you’re using a portable generator, be sure it’s grounded. A portable generator’s frame does not need to be grounded, and the frame might act as the ground:

The generator frame is bonded to the noncurrent-carrying metal portions of equipment such as the fuel tank, internal combustion engine, and generator housing, as well as the equipment grounding conductor terminals of the power receptacles that are part of the generator.

Instead of connecting to a grounding electrode system like a ground rod, the generator’s frame serves as the grounding electrode.

A transfer switch must be authorized for use and installed by a qualified electrician in accordance with the manufacturer’s installation instructions.

How to Ground Your Portable Generator?

Most people believe that grounding a generator is a difficult task that should be left to the experts. That’s not the case, though. Actually, chances are that you have pretty much everything that you’ll need for the job. All of these can be easily found both online and from your local Home Depot.

Tools & Equipment List for Grounding Your Generator

The majority of people believe that grounding a portable backup generator is a difficult task that should be left to specialists. However, this is not the case. Actually, you probably already have almost everything you’ll need for the job. They’re all readily available both online and at your local Home Depot.

To ground your portable generator, you’ll need the following items on hand:

Grounding Rod — A grounding rod is meant to be pushed into the ground and safely dissipate any electrical current. A copper rod of at least four feet in length is required for most portable generators, while a longer copper rod can make driving it deeper into the ground.

Grounding Wire — Grounding wire will link your generator’s grounding bolt to the grounding rod. The length of wire you’ll need is determined by the distance between your portable generator and the copper rod. Make sure to leave some additional wire on hand in case you need to drive the rod into the ground.

Hammer — To push the copper grounding wire into the ground, you’ll need a hefty, blunt tool like a hammer. A shovel depending on the terrain, may also be useful.

Pliers and Wrench — Wire strippers, Pliers and Wrench will be needed to strip the copper grounding wire and attach it to the copper grounding rod and the bolt on your generator.

Ground a Generator — 3 Steps

Step 1 — Hammer the Grounding Rod

The copper rod should be buried at least 8 feet deep or pounded into the ground. 8 feet is standard for any generator. This depth guarantees that any electrical discharge from the grounding rod does not electrocute anyone on the ground. The rod may be pounded in at an angle if you’re in rocky or difficult terrain.

Step 2 — Connect the Copper Wire

Remove around six to twelve inches of insulation from one end of the copper wire using a wire strippers or plier. Then, using your pliers, wrap the wire on the top of the grounding rod, making sure it is snugly twisted around the rod.

Step 3 — Connect the Generator

Using the other end of the copper wire, connect the generator to the copper grounding rod. When you do this, make sure the generator is switched off.

Find your generator’s grounding bolt and remove the nut slightly. Wrap the copper wire around the grounding bolt with your pliers after stripping the end one to two inches. When you’re finished, tighten the nut to keep the wire in place.

Finally Verify the Connection by Testing

The connection between the generator’s frame and the grounding terminals of copper rod is important for the equipment’s safe operation. Testing by a qualified electrician with the appropriate equipment can verify the connection. The ohmic resistance should be around zero and not fluctuate, as this suggests a loose connection.

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I am a mechanical engineer with years of experience working on Internal combustion engine and fixing electrical and mechanical systems, generators, transfer switches, and equipment related to storm water and sewage pumping stations.