Which of the following is NOT an example of a racking system?

• A. Ground-mounted
• B. Roof racking, suspended
• C. Roof racking, attached
• D. Roof racking, ballasted

Answer: (B)

Racking systems are the structures that physically hold and support PV modules, providing a defined load path and attachment method. Ground-mounted systems sit on the ground and are anchored, while roof-mounted systems come in two common forms: attached, where rails are fastened to the roof structure (often penetrating the roof), and ballasted, where rails are secured with weights without penetrating the roof. A roof mounting described as suspended isn’t a standard racking category because it implies hanging modules from the roof without the typical rail-based, wind-rated support path that penetrates or rests on ballast. This approach isn’t treated as a conventional racking system in IEC practice due to different load paths and safety considerations. Therefore it isn’t considered a valid example of a racking system. The other options reflect established mounting methods.