How To Ground A Portable Generator [Important!]


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Last Updated: March 16, 2022

A portable generator could save your life, but it could also endanger it. In fact, without a portable generator, I wouldn’t be writing this article.

Many people rely on portable generators to survive power outages. They use them to power sump pumps when there’s flooding, run CPAP machines to keep sleep apnea sufferers breathing, and stop food from spoiling by keeping the refrigerator going.

Unfortunately, portable generators also endanger lives, killing around 70 people every year. Not only do generators emit carbon monoxide, but they can also cause electrocution and create a potential fire hazard. Grounding your portable generator helps reduce the chances of such dangers occurring.

Everyone should know how to operate a generator safely.

We’ve already covered topics like can a generator run in the rain? and how long to run a generator for a fridge during a power outage.

Now it’s time to turn our minds to grounding.

What Happens If You Don’t Ground Your Generator?

diesel generator

In an electrical circuit, a hot wire conducts the current to its destination, while a neutral wire returns that current to its source. If anything disrupts that circuit, electricity will search for an easy escape route or path of least resistance. If your generator isn’t grounded, that path of least resistance could be anywhere, including your electrical equipment or wiring.

This puts you at risk of electrocution and puts your generator in danger of overheating and, potentially, bursting into flames.

It could also damage your electrical equipment, although most appliances are fitted with a circuit breaker or surge protection of some description.

Reasons You Should Ground A Portable Generator

If a grounded generator shorts, the electricity already has a safe, low resistant path to follow.

A neutral conductor connected to the ground provides a safe escape route for the current. This outlet stabilizes the electrical circuit by sending any excess voltage into the earth, which, in turn, dissipates that energy.

As the National Electrical Code states,

“Grounding is to ensure that the electrical system is safe against electric shock and fires by limiting the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines.”

Every electrical system must have an effective ground-fault current path installed. This must be a permanent addition to the system designed to carry fault current from the wiring system to the ground.

How Do I Know If My Generator Needs Grounding?

backup generator

I asked my husband about grounding a generator, and he looked dumbfounded.

Despite working with portable generators for over 20 years, he says he’s never grounded any of them. This is because most modern portable generators incorporate their grounding function into the metal frame that supports the system.

In this type of generator, the fuel tank, engine, and housing are surrounded by a metal frame. Any electricity escaping the system will flow through that frame and into the ground.

According to the Occupational Safety and Health Administration, in some instances, the frame of the portable generator need not be connected to the earth for the system to be considered appropriately grounded.

The frame acts as a replacement for the ground in three circumstances:

  • When the generator is only being used to power equipment mounted on the generator itself
  • The ground conductor terminals and non-current-carrying components of the generator are bonded to the frame
  • It’s a neutral bonded generator in which the neutral conductor is connected to the frame.

In other instances, you may be able to ground your generator without needing a grounding electrode.

A floating neutral generator doesn’t have its neutral conductor bonded to the frame. If, however, you connect it to your home’s grounded neutral conductor, you’ll still meet the requirements specified by the OSHA.

If you use it as a standalone, however, you’ll need to connect to a grounding electrode.

How To Ground A Portable Generator

To ground your generator you will need a grounding rod and some grounding wire. The rod will be driven into the ground, and the wire used to connect the rod to the grounding bolt on your generator.

Step 1: Insert the Grounding Rod

Hammer your rod into the ground close to your portable generator. The NEC requires that every ground rod be buried a minimum of 8 feet down. This is designed to protect people standing on the ground from being electrocuted should there be an electrical discharge. If you live in a particularly rocky area, you can hammer the rod in at a 45° angle rather than vertical.

Step 2: Connect your Grounding Wire to the Rod

First, strip the insulation off one end of your copper wire, exposing around six to 12 inches of wire. Use pliers to wrap this tightly around the top of the grounding rod.

Step 3: Connect your Generator to the Grounding Rod

Make sure your generator is switched off. Locate the grounding bolt on your generator and gently loosen the nut. Strip one to two inches of insulation off the end of your wire. Wrap the exposed end around the nut before tightening it up again.

Conclusion

Many modern portable generators come with their grounding system built into the frame. Other models need a grounding electrode to meet the requirements set out by the OSHA.

Grounding a portable generator makes it safer to use and protects you and your equipment against electrocution and fire. While hammering a grounding rod into the earth could be a difficult task, grounding a generator is a straightforward process that requires little technical know-how.

If you’re not sure if your generator needs grounding or lack the confidence to ground it yourself, get a professional in to give you a hand. After all, no one wants to create a fire hazard by being a bright spark!

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