Electrical
Surge Protection for Home and Business: Protect Your Equipment from Lightning and Spikes
Short answer
A surge is a brief voltage spike from lightning, grid switching or large motors that can damage electronics. Protect equipment with a surge protective device (SPD) at the distribution board, plug-in protectors for sensitive items, and good earthing. Solar systems, CCTV and networks need surge protection on power and data lines.
Where surges come from
- Lightning strikes near power lines or buildings.
- Switching of the grid or large machines.
- Faults on the network.
Layers of protection
| Layer | What it does | Where |
|---|---|---|
| Earthing | Gives surges a safe path to ground | Whole installation |
| SPD at the board | Clamps spikes entering the building | Distribution board |
| Plug-in protector or UPS | Final protection for sensitive items | At TVs, computers, routers |
| Data line protection | Protects network and camera cables | CCTV, Wi-Fi access points, outdoor cables |
| DC surge protection | Protects solar inverter and panels | Solar array and inverter |
Practical advice
- Have earthing tested; a surge device is only as good as its earth.
- Fit an SPD with the correct rating for your supply.
- Use a UPS or good-quality surge strip for computers and routers.
- Protect outdoor CCTV cameras and network cables.
- Consider a lightning protection system for tall or exposed buildings.
No protection is absolute
A direct lightning strike can overwhelm any device. Protection reduces the risk and is far cheaper than replacing equipment. Read more about earthing and RCDs.
Common questions
Is a surge protector the same as a power strip?
No. Many power strips have no surge protection. Check for a surge rating.
Does unplugging devices help?
During storms it can, but it is not practical for fixed equipment, so install proper protection.
Does my solar system need surge protection?
Yes, on both the DC and AC sides, with proper earthing.