How do surge protectors (SPD)work to protect devices?

Surge protectors (SPD) work by providing a safeguard against voltage spikes, which are sudden increases in electrical power that can damage or destroy electronic devices. Here's a step-by-step explanation of how surge protectors function to protect your devices:

1. Normal Operation:

   • When there is no surge, the surge protector allows electricity to flow from the power source through its outlets to your devices without interruption. It acts as a regular power strip.

2. Surge Detection:

   • The surge protector is equipped with voltage sensors that constantly monitor the electrical current coming into the device.

3. Activation of Protection:

   • When a voltage spike is detected, the surge protector activates its protective mechanism. This is typically a process that involves one or more of the following methods:

   a. MOVs (Metal Oxide Varistors):

   • MOVs are the most common surge protection devices. They are made of metal oxide materials that have a non-linear resistance. Under normal voltage conditions, they have high resistance, allowing only minimal current to flow through. However, when a voltage spike occurs, their resistance drops dramatically, allowing the excess voltage to be diverted through the MOV and into the ground, thus protecting the connected devices.

   b. Gas Tube Arrestors:

   • These are another type of surge protection device that uses ionized gas to conduct electricity. In a gas tube, when a voltage spike occurs, the gas inside the tube becomes ionized, turning into a conductor and allowing the excess voltage to be safely discharged into the ground.

   c. Silicon Avalanche Diodes:

   • These are semiconductor devices that can handle high voltages. They are designed to conduct electricity when the voltage exceeds a safe threshold, diverting the excess voltage away from the connected devices.

4. Dissipation of Excess Voltage:

   • The surge protector directs the excess voltage away from your devices and into the ground, where it can be safely dissipated without causing harm to your electronics.

5. Return to Normal Operation:

   • Once the voltage returns to a safe level, the surge protector resumes its normal operation, allowing electricity to flow to your devices as usual.

6. Indicators and Circuit Breakers:

   • Many surge protectors have indicator lights that show whether they are functioning properly. Some also have built-in circuit breakers that will cut off power to the outlets if a particularly strong surge is detected, further protecting your devices.

By providing a path of least resistance for the excess voltage, surge protectors effectively shield your devices from the damaging effects of power surges, ensuring their longevity and reliability. It's important to choose surge protectors that are rated for the specific voltage levels of your area and the sensitivity of your devices.