How do lightning or surges destroy equipment

Lightning and surges damage equipment mainly through three destructive effects: overvoltage breakdown, overheating from excessive current, and magnetic induction damage. Here’s a clear, concise explanation:

1. What are lightning / surge voltages?

Normal power lines carry a fixed voltage (e.g., 220V, 380V, 110V). A surge is a very short, extremely high voltage spike — often thousands to millions of volts — caused by:

Direct or nearby lightning strike

Switching large electrical equipment

Power grid faults

This voltage is far beyond what electronic circuits can withstand.

2. How they physically destroy equipment

① Overvoltage breaks down insulation & semiconductors

Electronic components (chips, diodes, transistors, ICs) have very thin insulation layers.

High surge voltage punches holes in insulation → short circuit inside the component.

Result: chip burnout, motherboard failure, power supply damage.

② Huge current causes overheating & melting

Lightning induces massive current in wires.

Current flows through tiny wires, PCB traces, and components.

Joule heating:

P=I2R— high current creates extreme heat instantly.

Result: Wires / PCB traces melt or vaporize

Components explode, burn, or turn black

③ Electromagnetic induction destroys distant equipment

Lightning does not need to hit the device directly.

It creates a fast-changing strong magnetic field.

This induces high voltage in nearby cables (power, network, telephone, CCTV).

The induced surge travels along the wire into equipment and damages it.

④ Arc & spark damage

High voltage can jump across gaps (between pins, connectors, terminals).

Creates an electric arc → high temperature → burns circuit boards, plastic, connectors.

3. Typical damaged equipment

Power supplies, adapters

Computers, servers, monitors

Routers, switches, network cards

TVs, audio, home appliances

Industrial controllers, PLCs, sensors

Security cameras, DVRs

All have sensitive integrated circuits that cannot survive high voltage spikes.

4. Summary in one sentence

Lightning and surges destroy equipment by forcing abnormally high voltage into circuits, breaking insulation, creating destructive current, overheating components, melting wires, and burning chips — often in microseconds.