Where do you ground coaxial cable?

Answered by Douglas Hiatt

When it comes to grounding a coaxial cable, it is essential to follow the guidelines set by the National Electrical Code (NEC). The purpose of grounding is to provide a safe path for electrical faults or lightning strikes to dissipate into the ground, protecting both the equipment and the people using it. In the case of a coaxial cable, proper grounding helps to prevent damage to the cable, reduce the risk of electrical shock, and minimize interference.

According to the NEC, the preferred method of grounding a coaxial cable is to connect it to the home’s ground electrode system (GES). The GES is typically established by a ground rod that is installed at the power meter and breaker box. This connection ensures that any electrical faults or surges that may occur in the coaxial cable are safely directed into the ground.

To create this connection, you will need to bond the antenna mast and the coaxial cable to the GES. Bonding refers to the process of creating a low-impedance path for electrical current to flow. This can be achieved by using a copper or aluminum grounding conductor, preferably with a minimum size of 10 AWG (American Wire Gauge).

Here is a step-by-step guide to properly grounding a coaxial cable to the home’s GES:

1. Locate the ground rod: Identify the ground rod installed at the power meter and breaker box. It is usually a metal rod or pipe driven into the ground.

2. Prepare the grounding conductor: Cut a length of copper or aluminum grounding conductor, ensuring it is long enough to reach from the mast or antenna to the ground rod. Strip the insulation from both ends of the conductor to ensure good electrical contact.

3. Attach the grounding conductor to the mast: Securely fasten one end of the grounding conductor to the antenna mast using appropriate hardware. Make sure the connection is tight and free of any corrosion.

4. Route the grounding conductor: Run the grounding conductor from the mast or antenna down to the ground rod. Ensure that the conductor is protected and securely fastened along its entire length to avoid any damage or disconnection.

5. Bond the grounding conductor to the ground rod: At the ground rod, create a secure and low-resistance connection between the grounding conductor and the rod. This can be achieved by using a ground clamp specifically designed for this purpose. Tighten the clamp securely to ensure good contact.

6. Bond the coaxial cable to the grounding conductor: At a suitable location near the ground rod, securely connect the coaxial cable to the grounding conductor. This can be done using a bonding clamp or other approved grounding device. Again, ensure that the connection is tight and free of any corrosion.

7. Test the grounding system: Once the grounding connections are made, it is important to test the system to ensure proper grounding. This can be done using a ground resistance tester or a multimeter set to measure resistance. Consult a qualified electrician or follow the manufacturer’s instructions to conduct the test accurately.

It is worth noting that while bonding the coaxial cable to the home’s GES is the preferred method, there are other options available as outlined in Section 250 of the NEC. These options include bonding to the grounding electrode conductor, the grounded interior metal water piping system, or the power service accessible metal raceway. However, the GES is generally considered the most reliable and widely accepted method.

Grounding the coaxial cable is a critical step in ensuring electrical safety and minimizing interference. Following the guidelines set by the NEC, it is recommended to bond the antenna mast and coaxial cable to the home’s GES, typically established by a ground rod installed at the power meter and breaker box. By properly grounding the coaxial cable, you can protect your equipment, reduce the risk of electrical shock, and maintain a reliable and interference-free signal.