How Do Surge Protectors Actually Work?

Electrical circuits are vulnerable to power surges - abrupt spikes in voltage that can damage sensitive electronics. A surge protector acts as a safeguard, diverting this excess voltage away from connected devices through grounding pathways, effectively shielding your equipment from harm.This guide explains how surge protectors actually work.
Surge protectors come in various forms to safeguard your electronics, including whole-house units, power strips, and wall-mounted models. Certain advanced models even feature battery backups, offering uninterruptible power supply (UPS) functionality.
The majority of surge protectors rely on a key component called a Metal Oxide Varistor (MOV), which acts as a voltage-sensitive switch. Under normal conditions, the MOV remains inactive, allowing standard electrical current to flow uninterrupted to your devices. However, when a power surge or spike occurs, the MOV instantly responds by lowering its resistance, diverting dangerous excess voltage safely to the ground wire.
It's important to note that MOVs degrade over time with each surge they absorb, meaning their protective capabilities diminish with use.
Pro Tip: Don't overlook communication lines—cables like Ethernet or phone lines can also transmit damaging surges. For comprehensive protection, choose a surge protector with dedicated ports for all power and data connections linked to your sensitive electronics.