Navigating Codes and Standards

As the solar industry grows and matures, PV installers and inspectors need to keep abreast of the latest in codes and standards.  It seems grounding a module to a metal racking structure appears to be one area of confusion and misinformation.  Consequently, a high level view of grounding and bonding methods and techniques as well as the relationships among existing and emerging standards will be presented for an educational and thought provoking discussion.

There's new language in Section 690.43(C) of the NEC stating: “Metallic mounting structures, other than building steel, used for grounding purposes shall be identified as equipment-grounding conductors or shall have identified bonding jumpers or devices connected between the separate metallic sections and shall be bonded to the grounding system.”  As a result, this aspect may get interpreted differently and could cause confusion among installers as well as AHJs.

In order to provide more clarity, a new set of requirements has recently been established. This new standard, UL 2703 – Rack Mounting Systems and Clamping Devices for Flat-Plate Photovoltaic Modules and Panels will focus on rack mounting systems and clamping devices pertaining to ground/bonding paths, mechanical strength and suitability of materials only.  Hopefully, this concerted effort for additional testing and recommendations will appease the industry skeptics and eliminate any controversy for a safe and long lasting installation.

Although there’s a limited number of approved grounding procedures for PV installations, having a road map to follow will definitely help the installers to perform their job in accordance with the NEC as well as the authorities to ensure the integrity of the code is obeyed.  Not only will this help spur innovation to develop well-engineered grounding means, but will also greatly benefit the responsible parties to get a grip on equipment grounding.