4. Earthing & Bonding for Protection · Page 2 of 6
Equipotential Bonding Explained
Keep metalwork and electrical references at similar potential during a surge.

Why bonding beats isolation myths
During a surge, trying to "isolate everything from earth" often creates dangerous potential differences. Bonding creates a common reference so SPDs and insulation see less stress.
What to bond
Main earthing bar, cable armor, metal pipes, cable trays, LPS down conductors, and SPD PE terminals should form a coherent bonding network per local code.
Star vs mesh
Sensitive rooms sometimes use structured bonding (star or mesh-BN). The SPD earth must still land on that system with minimal length.
