The Difference Between Surge Protectors and Circuit Breakers

To protect electrical safety, various devices capable of disconnecting circuits have been developed. Among them, Surge Protection Devices, Lightning Arresters, Leakage Protectors, Circuit Breakers, and Disconnectors are relatively well-known. Today, we will mainly understand the difference between Surge Protectors and Circuit Breakers.Surge Protection Devices (SPDs) and circuit breakers are commonly installed together in Distribution boxes andswitchgear cabinets.

A Surge Protection Device (SPD), also known as a "Lightning Protector" or "Surge Arrester", is used to limit surges caused by strong transient overvoltages in electrical circuits and communication lines, thereby protecting equipment. Its working principle is that when a transient overvoltage or overcurrent occurs in the line, the SPD will rapidly conduct, diverting the surge into the ground.

According to the type of equipment being protected, they can be divided into two categories: Power Surge Protectors and Signal Surge Protectors. Among them, Power Surge Protectors can be classified by capacity into: Primary Power SPDs, Secondary Power SPDs, Tertiary Power SPDs, and Quaternary Power SPDs. Signal Surge Protectors can be divided into: Network Signal SPDs, Video Signal SPDs, Integrated Surveillance SPDs (3-in-1), Control Signal SPDs, and Antenna Feeder Signal SPDs.

A Circuit Breaker, also known as an Air Switch, automatically disconnects when the current in a circuit exceeds the rated current, providing protection against faults such as short circuits and overloads in the circuit or electrical equipment. For example, power supplies for lighting, pump rooms, etc., can be controlled by circuit breakers. Its working principle is that when the current passing through the switch exceeds a certain level, heat generated causes a metal strip to bend, triggering the switch to trip and cut off the power, thereby protecting the equipment in the circuit from damage due to excessive current.

The differences between a Surge Protection Device and a Circuit Breaker are:

1.Different Working Principles:

An SPD conducts immediately when a transient overvoltage increases in the line, diverting the overvoltage to the ground.

A Circuit Breaker automatically disconnects when the current in the line exceeds the rated current, protecting the electrical equipment.

2.Different Protective Functions:

An SPD protects electrical equipment and communication devices in the line from damage caused by surges.

A Circuit Breaker protects against short circuits and overloads in the line.

3.Different Protection Ranges:

An SPD can protect both power supplies and equipment on communication lines.

A Circuit Breaker protects electrical equipment.