This standard provides guidelines for the design, installation, testing, and maintenance of lightning protection systems to safeguard buildings and structures against direct lightning strokes.
Recommendations for the design, installation, and maintenance of lightning protection systems for buildings and structures, often referenced alongside newer standards.
Quick Reference Values
Maximum earth resistance of lightning protection system10 Ohms
Standard spacing of down conductors20 m
Spacing of down conductors for structures >20m high10 m
Minimum cross-section for copper strip down conductor20 x 3 mm
Minimum cross-section for galvanized iron strip down conductor20 x 3 mm
Key Formulas
Risk index = A + B + C + D + E + F + G — Overall assessment of risk
Practical Notes
Do not assume lightning protection is mandatory for all buildings; use the Table 1 risk assessment index to logically justify its requirement.
The structural reinforcement steel of a building can be used as a down conductor provided electrical continuity is adequately welded and ensured.
Earth terminations of the lightning protection system must be bonded to the main electrical earthing system of the building to prevent dangerous potential differences.