What Type of Grounding System Is Most Commonly Used for Solar Arrays?

Radial Grounding System Design

A radial grounding system typically consists of a central grounding point, such as a grounding rod, with multiple radial cables connected to it. The radial cables are usually 4-6 AWG and are spaced 10-15 feet apart, depending on the system size and design. This type of system is ideal for solar arrays because it provides a clear and direct path to ground for fault currents, reducing the risk of damage to the system.

Grounding Rod Selection and Installation

The choice of grounding rod depends on the soil conditions and the system size. Typically, a 10-foot grounding rod is used for systems up to 10 kW, while a 20-foot rod is used for larger systems. The rod should be installed at a depth of at least 8 feet, with a minimum of 2 feet exposed above ground. The rod should also be bonded to the electrical panel and other metal components of the system.

Grounding System Testing and Verification

Grounding system testing is crucial to ensure the system is functioning correctly and safely. A simple method is to use a grounding tester, which is available at most electrical supply stores. The tester should be connected to the grounding point and the system should be energized. The tester will indicate the resistance of the grounding system, which should be less than 4 ohms for a radial grounding system. Regular testing and verification of the grounding system should be performed to ensure it remains safe and effective.