The Needs, Requirements and Process of Grounding a Portable Generator

Portable inverter generators have become an essential part of our lives these days, providing electricity during power outages or in areas with a complete absence of power. Factors like lighter weight, smaller size and lower fuel consumption make them an ideal choice for most power consumers.

grounding symbol

The most common earthing symbol, IEC 60417 No. 5017

However, like any other piece of technology, one must first understand how to use these portable generators. How does one to set them up? How do they operate? How to handle them safely? These questions must be answered before getting your hands on one of them.

The following article will explore one of the most crucial safety measures involved in setting up a generator – its grounding.

Definition of Grounding

The term “grounding” means connecting an electrical circuit to the ground. The electrical circuit is in this case the generator’s frame (since it is metal and can conduct electricity).

Commonly, a copper rod is installed to ground a portable generator.

Risks Involved if Not Grounded

electric shock sign on a wooden postThe frame of a generator is normally made from metal and thus can conduct electricity. Any stray or fault currents can flow through the metal frame. These currents can be very harmful to anyone touching the frame.

The risks involved in touching an ungrounded metal frame may range from mild, to severe electric shocks. In the worst cases, electrocution.

In the case of a fault current, the current may pass through an engine or a fuel tank. The fuel may immediately catch on fire, resulting in the generator burning down and possibly damaging nearby objects.

Grounding a generator minimizes these hazards by transferring the stray or fault current into the ground. Thus, anyone who accidentally comes in contact with the metal frame will be safe.

Do You Always Need to Ground Your Generator?

NO, you don’t always need to ground your generator. The choice of whether to ground a generator depends on the generator and how it is used.

Honda EG2800i used with a circular saw

For most use cases, with a modern portable generator, you don’t need to worry about grounding. Picture: Honda EG2800i

Most modern generators do not require grounding. However, some older generators may still need to be grounded before use.

The simplest way to find out if your generator needs to be grounded or not is to consult the generator’s manual provided by the manufacturer.

In case you are on a construction or camping site and don’t have the manual with you; you can perform these two checks:

  1. Are your powered appliances directly connected to the generator using the receptacles mounted on the generator? If yes, then you may proceed without grounding, provided that the next condition is also met.
  2. All the generator’s equipment must be bound to its metal frame. This includes the tank, engine, generator housing, etc.

If the above conditions are met, you do not need to ground your generator. As, in that case, the metal frame replaces a grounding rod.

If the above conditions are not met, you must first ground your generator before proceeding any further.

However, there is an exception! Even if both conditions are met, if your generator is plugged into your home circuit or building directly, then grounding is a must.

For more detailed information on grounding requirements, you can visit OSHA’s guide for grounding requirements for portable generators.

Process of Grounding

Tools Required

  1. Copper grounding wire: A high-quality copper wire to connect grounding rod with the generator frame (for help with gauged copper, see this article by doityourself.com).
  2. A set of wire strippers: Required to strip away insulation from the copper wire.
  3. Grounding rod*: More info below.
  4. Hammer: Required to drive the copper rod into the ground.
  5. Pliers: To wind copper wire tightly around the grounding rod.
  6. Wrench: To loosen and tighten the generator’s grounding bolts.
  7. Protective clamps/fittings: For any above-ground parts of the ground rod.
  8. Water (optional): To soften hard ground.
  9. Shovel (optional): For digging (rocky terrain).
  10. Soldering equipment (optional)

*Some info regarding the grounding rod

extract of NEC 250.52

Extract of the 250.52 (A)(5) section of the NEC

As for anything electricity-related, the NEC has standards for grounding rods as well, which must be strictly followed for maximum safety and compatibility of all the electronics in your circuit. Grounding rods are covered by the NEC 250.52 (A)(5).

In summary, a grounding rod (not to be confused with pipes or conduits), must be at least 8 ft in length and 5/8 in. in diameter. They can be made of stainless steel and copper or zinc-coated steel.

In case you want to use a pipe, conduit or grounding electrodes of a different type (stores offer them as UL listed), refer to the NEC 250.52 (A)(5).

Process

extract of NEC 250.52(G)

Extract of NEC 250.52 (G) section of the NEC

  • Installing the ground rod: Drive the grounding rod into the ground using either a mallet or a hammer if the soil is soft. If the ground is hard, you may need to use a sledgehammer. You can also use water to soften the soil first and then hammer the copper rod down the ground. At least 8 ft of the rod should be in contact with the earth according to NEC 250.52 (G).
    If rock bottom does not allow otherwise, you may install the rod at an angle not exceeding 45°. In such cases, the grounding rod must be buried in an at least 30 in. deep trench (a hole), in accordance to NEC 250.52 (G).
    Any remaining above ground parts must be covered by a protective clamp or fitting regardless of the rod depth.
  • Connecting the copper wire to the ground rod: Remove a part of the insulation of the grounding copper wire using the wire strippers. Wound this copper wire around the grounding copper rod tightly using pliers. Alternatively, you may solder the grounding wire to the rod if you have the equipment to do so.
  • Grounding the generator: Locate the grounding bolt of the generator. Loosen it with a wrench. Wrap the copper grounding wire around it and tighten the bolt. Again, if your toolshed allows it, you may solder the wire to the bolt.

Conclusion

Grounding a generator is of great importance while setting it up. It can save you and your colleagues from potential risks, including electrocution.

Thus, the knowledge of grounding a generator is crucial for every person who plans to buy or already has one.

For regular campers or construction site workers, one could be advised to get a generator that does not require grounding. This would not only be safer, but also save the time spent setting up the system.

Disclaimer: This article is only advisory in nature. GeneratorBible.com will not be responsible for any damage, injury or any other event resulting from this article. If you are not sure what you’re doing, we would highly suggest you consult a trained professional.

Paul

Paul

Manager & Editor of generatorbible.com. Early retired from the OPE industry, living in South Carolina. He now mostly spends his time traveling and taking care of his wife and grand-children.

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