PV racking not only holds modules but also forms continuous equipotential grounding to prevent lightning and leakage. Grounding (star/toothed) washers are key to electrical bonding between module frames and rails.
Anodized module frames and galvanized rails have non-conductive coatings; plain washers cannot conduct. Grounding washers have sharp teeth that penetrate anodizing and zinc coating during installation, forming a metal-to-metal low-resistance path for equipotential bonding.
Commonly 304/316 stainless toothed grounding washers are used with module clamp bolts. Install to manufacturer torque so teeth embed without cracking frames. Design at least two reliable bond points per module-to-rail connection.
System grounding resistance typically ≤4Ω per local code; transition resistance between bond points recommended ≤0.1Ω. Post-installation, test with micro-ohmmeter抽样 to confirm continuity.
The solar fastener range supplies grounding washers, module clamps and grounding solutions.