How to Ground your Portable Generator

Portable generators give you the freedom of electricity on the go. That means you can take the comforts of home with you camping, electrify outdoor events, power tools at a remote worksite, and more.

While portable generators are relatively safe compared to other motor-driven tools, there are still some important safety considerations to keep in mind. One of the most important of these is recognizing whether your generator needs to be grounded and understanding how to do it.

Not all portable generators need to be grounded, and some may only need to be grounded in specific circumstances. In this article, we’ll cover what grounding is, how to tell if you need to ground your portable generator, and explain how to do it safely.

Understanding Electrical Grounding

When electricity is flowing through a set of wires, it is always seeking to dissipate energy by returning to a ground. In a normal electrical system, like that of your generator, electricity flows through “hot” wires to a series of neutral wires.

But, if anything happens to that normal electrical circuit, electricity will flow through the path of least resistance. If your generator isn’t grounded, that path of least resistance could allow electricity to flow in places it shouldn’t be – which can cause electrocution, spark a fire, or cause other dangerous situations.

Grounding provides a backup path of least resistance for electricity to flow. The term grounding is used because in many electrical systems, that backup path leads directly into the ground where it can pose relatively little risk.

Do You Need to Ground Your Portable Generator?

All portable generators need to be grounded in order to be safe. But, whether you need to do anything special to ground your generator depends on how it was designed.

Most modern portable generators are designed such that the metal frame around the generator acts as the path of least electrical resistance. In this case, the engine, fuel tank, and generator housing are all bonded to the frame, so that any electricity flowing through the generator outside of the wiring is grounded by the frame.

The easiest way to tell if your generator needs to be grounded is to check your owner’s manual. The manufacturer should provide extremely clear instructions on whether or not your generator needs to be grounded.

If you don’t have the manual or it is not clear, you can also inspect the construction of your generator. If the generator’s transfer switch gives you the option to transfer current to a neutral ground conductor, your generator’s components consist of a separately derived system. This means you will need to connect your generator to a separate grounding rod.

How to Ground Your Portable Generator

If you find that you need to ground your portable generator, you’ll need to wire your generator’s transfer switch to a grounding rod.

Tools and Equipment To Ground Your Generator

You’ll need to have the following equipment on hand to ground your generator:

  • Copper Grounding Rod – A copper grounding rod is designed to be driven into the ground, where any electrical current can be safely dissipated. For most portable generators, you’ll need a copper grounding rod that is at least four feet in length, although a longer rod can make driving it deeper into the ground easier.
  • Copper Grounding Wire – Copper grounding wire will be used to connect the grounding bolt on your generator to the grounding rod. The amount of wire that you need will depend on the distance between your generator and your buried rod. Be sure to give yourself some extra wire since this can make driving the rod into the ground easier.
  • Wire Strippers, Pliers, and Wrench – These tools will be used to strip the copper grounding wire and to connect it to the grounding rod and your generator’s grounding bolt.
  • Hammer or Mallet – You’ll need a heavy, blunt object to drive the copper grounding wire into the ground. Depending on the terrain, a shovel or spike may also come in handy.

Step 1: Hammer in the Copper Grounding Rod

The copper grounding rod should be hammered into the ground or buried at least 8 feet deep. This depth ensures that any electrical discharge from the grounding rod won’t electrocute people standing on the surface. If you are in rocky or difficult terrain, the rod can be hammered in at an angle of up to 45 degrees.

Step 2: Connect Copper Wire to Grounding Rod

Use your wire strippers to strip out about six to 12 inches of insulation off one end of the copper wire. Then wrap this around the top of the grounding rod, using your pliers to make sure it is wound tightly around the rod.

Step 3: Connect the Generator to the Grounding Rod

You can connect your generator to the grounding rod using the other end of your copper wire. The generator should be turned off when you do this.

Locate the grounding bolt on your generator and loosen the nut slightly. Strip the end of the copper wire one to two inches and then wrap it around the grounding bolt with your pliers. When done, tighten the nut to ensure the wire remains firmly in place.

Should You Ground Your Generator?

Most modern generators are designed as a single system, such that the frame serves to ground the generator. But, if you find that your generator requires an external ground, grounding it properly is an extremely important part of safe generator operation.

Grounding your portable generator can be fast and simple once you have the right tools on hand. Once it’s grounded, you can operate your generator without worrying about potential electrocution in the event of an electrical failure.

6 thoughts on “How to Ground your Portable Generator”

  1. My Predator generator (4375 starting watts) will be sitting in a shed that is 15 feet away from an electrical outlet on the side of my house. The outlet is grounded via the house electrical system. Instead of pounding a copper rod into the ground could I just connect a copper wire to the ground prong of a 3-prong “dummy” plug (nothing connected to the hot or neutral prongs) and then just plug it into the outlet? Would that count as an appropriate ground for my generator? Thanks for your opinion on this.

    Reply
  2. How do I sink a 4 foot rod 8 feet into the ground? I live in Northern California, where the adobe is hard and full of stones. Even if I could somehow dig a 4-foot post-hole, I could never drive a rod into the ground from there because the stones would block its path. (I recently broke a steely mattock head just trying to dig a hole to plant flowers!) My new Predator 3500 generator unequivocally says it needs to be grounded. What should I do?

    Reply
      • Sorry, I also live in Northern CA, and agree with the person asking the question. Driving it in in any direction is not an option. Digging a 3’ hole took me over a week with pick ax & other tools, and was only possible when the water table dropped a specific depth and before it dropped any farther. That was in the least rocky part of my property. So, without heavy machinery, and only if a wide surface is dug, is anything but a T-post put into the ground (then requiring special equipment to remove if you need to, since the earth has turned to cement for most of the year). So, any suggestions for other options?

        Reply

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