How To Ground A Portable Generator

It is vital to ground your generator correctly before you use it.

Grounding the generator reduces the chance of electrical shocks and keeps you safe.

Many modern generators will have something built in to automatically ground the electrical current.

It is vital to check your generator and its specific grounding requirements to ensure the safety of you and your family. It is also referred to as ‘earthing’ and helps to prevent fires and electrocution occurring. 

Ungrounded generators can cause life-threatening accidents and it is vital to take the necessary safety precautions. 

What Does Grounding Mean?

Grounding is an important safety precaution to take with your portable generator. It means you provide the electricity running through the generator with a path of least resistance to return to the ground. In layman’s terms, it is a safe way for excess electricity to leave the circuit. 

If your generator contains a circuit breaker, this will cut off the electricity running through the circuit in the event a malfunction occurs. This buildup of electrical energy is what gives you static shocks. A grounding wire is what then transfers this energy out of the circuit and into the ground. 

Different Systems

The design of portable generators usually incorporates a metal frame around the actual generator.

The electrical components, such as the engine, fuel tank, and generator housing are bonded to this frame. This tends to act as the path of least resistance and in effect, grounds the generator. This is known as a non-separately derived system.

It is only necessary to ground generators with separately derived systems. This is because they do not have a direct electrical connection to conductors from outside the original system,. 

How Do You Know If Your Generator Needs Grounding?

The easiest way to check this is to look in your generator’s owners manual. They will make it very clear if your generator needs grounding and how to do this. 

If you do not have access to the manual, you can look at the generator itself. Look at the transfer switch on the generator.

See if there is an option to transfer the current to a neutral ground conductor. This means that there is a completely separate system your generator runs off. This will mean that you need to connect your generator to a separate grounding rod. 

If your appliances are connected to the generator directly and the electrical components are bonded to the metal frame, your generator does not need grounding. This is because the metal frame acts as the grounding rod.

However, if your generator is connected to your home’s mains system, you must ground it. 

What Do You Need To Ground A Generator?

There are a few pieces of equipment you will need to ground your generator. These are a copper grounding rod, copper grounding wire, wire strippers, pliers, a wrench, and a hammer. 

The copper grounding rod is what forces the excess electricity into the ground. This will allow the current to safely dissipate. This should be at least 8 foot long, but the longer the rod the deeper into the ground you will be able to force it.

The grounding rod should be at least ⅝ inches in diameter. Copper is the most desirable material for grounding rods, although stainless steel and zinc-coated steel will also work. 

Copper grounding wire is used to connect the grounding rod to the generator. There should be a grounding bolt on the generator somewhere for this wire to connect to.

This wire should be at least the distance from the generator to the grounding rod, preferably plus a little more. This excess will make it easier to connect the wire and to drive the rod deeper into the ground.

The tools are fairly self-explanatory and will manipulate the wire and rod. The wire strippers are used to strip the casing off and expose the copper fibers inside the wire. The pliers are to shape the exposed wire and the hammer is to force the rod into the ground.

How Do You Ground a Generator?

You will first need to hammer the copper rod into the ground. You should do this at a distance of around 6-8 feet from your generator. 

If you are attempting this on very solid ground, we recommend pouring a little water on the floor to soften the earth. If you are on rocky ground, we suggest hammering it in at a 45 degree angle.

Use the hammer to drive the rod into the ground at least 3 feet deep, although the deeper it is the safer. A depth of 8 foot is recommended for ultimate safety. This ensures that the electrical current will not harm anyone standing on the surface near the rod. 

Get your copper wire and use the wire strippers on it. You should strip the insulation coating off of the wire about 6-12 inches from one end. Wrap the exposed end of wire around the top of the copper grounding rod. Use your pliers to ensure it is tightly wrapped.

Strip the other end of the copper wire about 2 inches from the end. Ensure the generator is switched off before you touch it with the wire. 

Loosen the grounding bolt on your generator. Wrap the exposed end of the copper wire around the bolt using your pliers.

Reattach and tighten the nut to lock the wire in place. 

Important Safety Precautions

Ensure you treat your generator as described in the owner’s manual.

As it is a complex electrical device, you should take great care when interacting with it. It should always be turned off when you are touching it or any of the wires connected. 

Do not attach portable generators directly to a home or caravan. 

Ensure the cords you are using for connecting appliances to the generator are heavy-duty and have a grounding conductor. 

If you are worried at all, or unsure of what to do, please do not hesitate to contact a qualified electrician.