LIGHTNING PROTECTION GENERAL
Lightning voltages and currents (up to 200kA) are very high and do cause damage to buildings and electrical or electronic equipment.
Direct Strike: is when lightning strikes a building resulting in mechanical and structural damage. Protection against direct strike lightning
is achieved by installing an air termination system, comprising finials and ridge conductor and an earthing system. A direct strike may
also result in induced over voltages to power cables, telephone lines, data lines, resulting in damage to electronics, TV's, computers,
data lines, electrical equipment etc. Surge protection devices (SPD) need to be installed for protection.
Indirect Strike: is when lightning may strike "in the area"- the power lines, the ground, the telephone lines, causing surges in the
building's power supply, telephone and/or data lines resulting in damage to electronic equipment, computers, TV's, telephones etc.
Surge protection devices need to be installed in the power supply and cable link systems for protection.
The drawing below is to be used as a product guide and it is not intended to be a definitive method on earthing and lightning protection.
There are SABS and IEC Standards that clearly define the full installation and design, the drawing for product selection is a guide.
Refer to p 36 for a Lightning Risk Assessment computer programme that is fully compliant with the latest IEC 62305 Standards.
Lightning is a phenomenon of nature and is unpredictable. No protection warranty is given or implied with the purchase of products.
Please contact us for assistance in the design of a lightning protection system and application of products.
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