Can I Install a Separate Ground Rod for My Garage?

Specifications

• Garages with their own grounding rods use a conductive rod or pipe that is at least 8 feet in length to provide a safe path for excess current. The National Electrical Code requires you to drive grounding rods deeply into the ground at an angle less than 45 degrees away from straight up and down. These rods are typically made of steel with a sharpened end so that you can drive them into the ground with less effort.

Alternatives

• Underground metal plumbing near the garage that is at least 8 feet long is a cost-effective alternative to installing a new ground rod. The ground wire from your electrical box is run to the pipe and welded in place or attached to the outside of the pipe using a corrosion-resistant connector. In extremely rocky yards driving an 8-foot steel rod into the ground is a difficult task. If your yard is extremely rocky you can use a grid of copper wires or pipes buried beneath the ground instead of a grounding rod. Increasing the size and depth of this grid will improve its ability to protect the electrical devices in your garage.

Ground Wiring

• Most grounding wires are made from copper and are welded to the grounding rod or attached using a clamp. The appropriate size of the copper wire used to connect your grounding rod and the electrical panel for your garage is based on the load of the circuit it is protecting. A circuit protected with a 30-amp circuit breaker would only require a 10-gauge copper ground wire while a 400-amp circuit would require a larger 3-gauge wire. If you are using equipment in your garage that is sensitive to changes in voltage, you can increase the size of your grounding wire to limit changes in the voltage to your garage.

Considerations

• If your garage is attached to your home, it is usually more cost effective to use the grounding system built for your home. In homes with detached garages it is often cheaper to install a separate grounding rod for the garage rather than installing a ground wire between the garage and the ground for your home. In most cases, a separate grounding rod is only required if the power supplied to your garage is not directly connected to your home.