Lightning is the first leading cause of natural-disaster-related death in the World.

In India, among the direct accidents reported on human beings, it appears that more than 2000 people die every year due to lightning. Most of these accidents occur on remote open sites like agricultural fields, mines, large industrial sites, tea plantations, etc.

Fundamentally, every electrical installation needs a reliable earthing system. A Good earthing system is important for

• Safety of human and animal life
• Limiting damage to electrical equipment in case of fault / lightning
• Correct operation of the electricity supply network and to ensure good power quality & reliability.

The resistance to the earth of a given electrode depends up on electrical resistivity of the soil in which it is installed and the resistance of the electrode. However, soil resistivity is the important factor in deciding which of many protective systems to adopt for earthing.

A Lightning Strike emits very important electromagnetic radiations. These radiations and the over-voltages and surges induced by such radiations can have dramatic consequences on any electronic or electrical devices. It can accelerate drastically the ageing process or damage partially the equipment or even destroy it totally the equipment.

Switching of facility loads, opening, and closing of disconnects on energized lines, switching of capacitor banks, re – closure operations and tap changing on transformers can all cause transients. Poor or loose connections in the distribution system can also generate transients.