Surge protector, also called lightning protector, is an electronic device that provides safety protection for various electronic equipment, instruments, and communication lines. When a peak current or voltage suddenly occurs in an electrical circuit or communication line due to external interference, the surge protector can conduct and shunt the current in a very short time to prevent the surge from damaging other equipment in the circuit.
Principles and classifications of surge protectors
The working principle of the surge protector is to utilize the characteristics of non-linear components. When the voltage or current exceeds a certain threshold, its impedance undergoes a sudden change, thereby guiding the excessive current or voltage to the ground or other circuits to protect the affected area. Protected equipment or systems.
According to different working principles, surge protectors can be divided into three types: voltage switching type, voltage limiting type and combination type. The voltage switching surge protector exhibits high impedance when there is no instantaneous overvoltage. Once it responds to the lightning instantaneous overvoltage, its impedance suddenly changes to low impedance, allowing lightning current to pass. It is also called “short-circuit switching SPD”. When there is no instantaneous overvoltage, the voltage-limiting surge protector has a high impedance. However, as the surge current and voltage increase, its impedance will continue to decrease, and its current and voltage characteristics are strongly nonlinear. It is sometimes called a “clamp” Pressed SPD”. The combined surge protector is composed of a voltage switching type component and a voltage limiting type component. It can display characteristics of voltage switching type or voltage limiting type or both, depending on the characteristics of the applied voltage.
According to different uses, surge protectors can be divided into three types: power line SPD, signal line SPD and hybrid SPD. Power line SPD is used to protect various electrical equipment in the power system, such as transformers, generators, distribution cabinets, etc., to protect against indirect lightning and direct lightning effects or other transient overvoltage surges. Signal line SPD is used to protect various electronic equipment in communication systems, such as telephones, faxes, networks, monitoring, etc., to protect signal line overvoltage generated by lightning induction or switching operations. Hybrid SPD refers to the function of both power line SPD and signal line SPD, and is used to protect equipment that requires both power and signal input and output, such as computers, servers, industrial computers, etc.
| Type of Surge Protector | Working Principle | Application |
|---|---|---|
| Voltage Switching Type | High impedance under normal conditions, switches to low impedance during instantaneous overvoltage (lightning). | Power system protection – transformers, generators, distribution cabinets. |
| Voltage Limiting Type | High impedance under normal conditions, decreases impedance as surge current and voltage increase. Nonlinear characteristics. Also known as “clamp pressed SPD”. | Power system protection – indirect lightning, direct lightning effects, transient overvoltage surges. |
| Combination Type | Composed of both voltage switching and voltage limiting components. Can exhibit characteristics of either or both types based on applied voltage. | Versatile protection for equipment requiring both power and signal input/output – computers, servers, industrial computers. |
| Power Line SPD | Protects electrical equipment in the power system against indirect and direct lightning effects or transient overvoltage surges. | Transformers, generators, distribution cabinets. |
| Signal Line SPD | Protects electronic equipment in communication systems against signal line overvoltage from lightning induction or switching operations. | Telephones, faxes, networks, monitoring. |
| Hybrid SPD | Provides dual protection for equipment requiring both power and signal input/output. Combines features of power line and signal line SPD. | Computers, servers, industrial computers. |
Installation and use of surge protectors
The installation location and method of the surge protector should be selected according to different protection levels and protection objects. Generally speaking, surge protectors should be placed as close as possible to the equipment or system being protected to reduce the induced voltage introduced. At the same time, the surge protector should share a grounding system with the protected equipment or system to ensure effective shunting. The wiring of the surge protector should be as short, thick and straight as possible to reduce line impedance and inductive reactance. The installation of surge protectors should comply with relevant standards and specifications, such as GB 50057-2010 “Lightning Protection Design Code for Buildings”, etc.
During the use of a surge protector, its working status and performance should be checked regularly. Generally, surge protectors have status indicators or remote signaling outputs that can show whether they are working properly. If the surge protector is found to be damaged or ineffective, it should be replaced or repaired in time. At the same time, attention should be paid to the rated parameters of the surge protector, such as maximum continuous operating voltage, maximum discharge current, protection voltage, etc., and appropriate models and specifications should be selected to meet the requirements of the equipment or system being protected.
| Aspect | Recommendations |
|---|---|
| Installation Location | Close proximity to the protected equipment or system to reduce induced voltage. Share grounding system for effective shunting. |
| Wiring | Short, thick, and straight wiring to minimize line impedance and inductive reactance. |
| Compliance with Standards | Adherence to relevant standards and specifications, such as GB 50057-2010 “Lightning Protection Design Code for Buildings”. |
| Regular Checks | Periodic checks of working status and performance. Look for status indicators or remote signaling outputs. |
| Maintenance and Replacement | Prompt replacement or repair if the surge protector is damaged or ineffective. |
| Consideration of Rated Parameters | Attention to rated parameters like maximum continuous operating voltage, maximum discharge current, protection voltage, etc. |
| Model and Specification Selection | Choose appropriate models and specifications based on the requirements of the equipment or system being protected. |
Advantages and functions of surge protectors
The surge protector is a simple, effective and economical lightning protection device. It can effectively protect various electronic equipment, instruments and communication lines from the hazards of lightning and other instantaneous overvoltages, and improve the reliability and safety of the equipment. Safety, reduce casualties and property losses caused by lightning. The scope of use of surge protectors is very wide, covering almost all fields that require electrical and electronic equipment, such as industry, agriculture, transportation, communications, education, medical care, finance, national defense, etc. Surge protector is an essential equipment for lightning protection in modern society. It is an important measure to improve social and economic benefits and protect the safety of people’s lives and property.