How Does a Surge Suppressor Work?

1. Surges are sudden jumps in electrical current caused by irregularities in the power lines. When the surge comes through the power lines, into a house and through the outlet, the sudden spike in current can cause damage to appliances and household electronics. In most surge protectors on the market, there is a component inside called a Metal Oxide Varistor (MOV). The MOV exists to safely re-route the surges.
2. A Metal Oxide Varistor consists of three components, a portion of metal oxide connected via two semi-conductors to the surge protector's power and ground lines. The semi-conductors are highly sensitive to current and voltage. When voltage is below a certain level, the electrons in the semiconductors flow in such a way as to create a very high resistance. When a surge comes through, the semi-conductors detect the jump and respond to the MOV. When the voltage is past a safety limit, the MOV absorbs the excess current and passes it via the ground line.
3. Once the excess current is dealt with, the MOV detects the drop in voltage to regular levels and does not absorb and redirect the regular current. The MOV functions as a run-off valve which catches only the excess and does not interfere with the regular voltage and current.

Resources

• Belkin (Surge Protector Manufacturer)