At LSP, we design AC Surge Protector Devices with one purpose: uncompromising protection for your critical systems. Built on strict IEC/EN 61643-11 standards and modular architecture compatible with 3+1 and 4+0 configurations, our solutions ensure seamless integration wherever protection is needed.
Using premium components from global leaders such as Phoenix Contact—featuring MOV and GDT technologies—our portfolio spans Type 1, Type 2, and Type 3 SPDs, delivering certified surge protection for every application, from renewable energy and telecom to industrial automation.
LSP ensures long-term reliability while maintaining flexibility and compliance with international standards.
As one of China’s professional surge protection companies, we provide certified and reliable solutions for partners worldwide. In certain applications, such as photovoltaic and energy storage systems, AC Surge Protector and DC Surge Protector are often used together for comprehensive protection.
As one of the best surge protector brands, LSP ensures unmatched protection and reliability, safeguarding your electrical systems with superior performance.
Certified with 8/20 waveform and 10/350 waveform tests, our SPD endures In = 20kA (±5 times) and Imax = 40kA (±1 time), ensuring it performs excellently under both lightning and switching surges, offering complete protection to your electrical systems.
Unlike traditional SPDs with basic moisture protection, our MOV encapsulation design prevents moisture infiltration, reducing failure risks and extending lifespan in humid environments, ensuring stable performance.
Our SPD features an internally developed tripping mechanism that isolates and extinguishes arcs, preventing fires and ensuring safe disconnection even under extreme lightning conditions, providing maximum safety for your equipment.
Our Surge Protection Device uses reinforced metal contacts (8 mm × 0.8 mm). This robust design enhances conduction and strength, enabling the device to withstand high surges while ensuring stable, long-term protection for connected equipment.
Benefit from high-precision AC surge protector with robust durability. Features such as fast response mechanisms, optimized clamping voltage, and advanced MOV/GDT components safely redirect surges, extending the lifespan of sensitive equipment while maintaining consistent performance.
We use high-quality MOVs from LKD and GDTs from Vactech to ensure the stability and lightning protection performance of our AC surge protectors.
Robust metal lead pins (0.8 mm thick, 8 mm wide) withstand high electrical potentials without breaking.
Our R&D team’s optimized low-temperature trip mechanism and advanced soldering process enhance arc suppression and fire prevention.
Every AC surge protector undergoes rigorous testing; only devices meeting our standards are approved. All AC Surge Protectors are TUV, CB, and CE certified.


LSP stands out among ac spd manufacturers in china, offering reliable, certified surge protection solutions and expert support to ensure your systems are always safe and operational.
Our manufacturing processes strictly adhere to ISO9001, ensuring compliance and efficiency. Our surge protectors are fully certified with TUV, CB, and CE, guaranteeing superior quality and suitability for global markets.
In the electrical field, we have independent R&D capabilities. Our R&D team, with 20 years of experience, provides technical support to help you realize your technical visions.
Our quality control system integrates advanced testing procedures, including lightning impulse tests and multiple durability evaluations, to ensure SPD reliability under surges, heat, corrosion, and fire risks. Consistency checks on solder durability and unified welding temperatures further guarantee long-term stability and safety.
We offer more to our valued customers! Including high-quality corrugated cardboard packaging, 3D animation materials for marketing, and regulatory and certification support.
We also provide 7-day return and 30-day exchange policy. Shipping costs and duties are covered by us during the warranty period.
Our experienced team manages inventory and production, maintaining a steady stock of materials to handle peak periods. We complete and ship regular orders within 15 days and custom orders within 30 days, maintaining a 96% on-time rate!
Our AC surge protector solutions serve diverse sectors: datacenters, LED systems, security systems, industrial installations, wind turbines, domestic and industrial photovoltaics, solar farms, energy storage, and water treatment facilities.
As surge protector suppliers, we empower multiple industries with customized protection and proven expertise.









Our AC surge protectors are used across datacenters, LED systems, security systems, industrial installations, wind turbines, domestic and industrial photovoltaics, solar farms, energy storage, and water treatment facilities. Each device provides reliable surge protection AC tailored to specific environments.
A surge protection device (SPD) is designed to protect electrical systems and equipment from surge events by limiting transient voltages and diverting surge currents.
When a transient voltage occurs on the protected circuit, an SPD limits the transient voltage and diverts the current back to its source or ground.
To work, there must be at least one non-linear component of the SPD, which under different conditions transitions between a high and low impedance state.
At normal operating voltages, the SPDs are in a high-impedance state and do not affect the system. When a transient voltage occurs on the circuit, the SPD moves into a state of conduction (or low impedance) and diverts the surge current back to its source or ground.
This limits or clamps the voltage to a safer level. After the transient is diverted, the SPD automatically resets back to its high-impedance state.
Surge protection devices contain at least one non-linear component (a varistor or spark gap), its electrical resistance varying in the function of the voltage which is applied to it.
SPD is designed to limit transient overvoltages of atmospheric origin and divert current waves to earth, so as to limit the amplitude of this overvoltage to a value that is not hazardous for the electrical installation and electric switchgear and controlgear.
The operating principle of a surge protection device is as follows:
Type 1 surge protection device SPD is used in unmetered areas. They must satisfy the most stringent requirements, as they are supposed to protect against the effects of direct lightning strikes. The demand placed on the short-circuit current rating is very high in a typical main distribution installation environment. In order to be able to meet these requirements, powerful technology, such as spark gap technology, is required.
Type 1+2 surge protection device SPD are lightning current arresters that, in addition to the lightning current test, also fulfill the required tests of type 2 surge protection device SPD. The Type 1+2 surge protection device SPD offers a special feature. It combines powerful spark gaps directly with varistor-based surge protection devices.
Type 2 surge protection device SPD with a low discharge capacity are installed in the metered area. They are generally installed in sub distributions or machine control cabinets.
These surge protection devices must be able to discharge induced overvoltages from indirect lightning strikes or switching operations, but do not have to handle direct lightning strikes. Discharge technology with fast response behavior – such as varistor technology – has proven itself here.
Type 3 surge protection device SPD with the lowest discharge capacity, also known as device protection, is installed as close as possible to the end device. Special surge protection devices are needed for signal lines. These are also installed immediately upstream of the end devices to be protected.
Type 3 surge protection device SPD are available in a wide range of designs to suit the various different installation environments. In addition to standard DIN rail mounting, there are products for installation in sockets or for direct mounting on a PCB of the end device.
Technologically speaking, type 3 surge protection device SPD is similar to type 2 surge protection device SPD, which is based on varistors, but the requirements concerning discharge capacity are even lower compared to type 2 surge protection device SPD.
Type 2 and Type 3 surge protection device SPD is provided above all on cables that lead into a building from the outside.
Where multiple devices are required to protect the installation, they must be coordinated to ensure correct operation. Items supplied by different manufacturers should be confirmed for compatibility, the installer and manufacturers of the devices are best placed to provide guidance on this.
A surge protection device (SPD) or simply a surge protector is a device used to protect electronic devices from power surges or transient voltage.
The surge protection device (SPD) is a component of the electrical installation protection system.
This surge protection device (SPD) is connected in parallel to the power supply circuit of the loads that it has to protect (see Figure). It can also be used at all levels of the power supply network.
Surge protection device (SPD) connected in parallel has a high impedance. Once the transient overvoltage appears in the system, the impedance of the device decreases so surge current is driven through the surge protection device (SPD), bypassing the sensitive equipment.
An AC Surge Protective Device (AC SPD) is a type of Surge Protective Device (SPD) specifically designed for alternating current (AC) systems, such as those used in homes, commercial buildings, and industrial power distribution. Its main function is to instantly divert excessive voltage to the ground when voltage spikes occur due to lightning strikes, power grid switching, or equipment start-up, thereby protecting the connected electrical equipment from damage.
In contrast, a DC Surge Protective Device (DC SPD) is used in direct current (DC) systems, such as solar photovoltaic systems, EV charging stations, telecom base stations, and energy storage systems, to prevent surge voltages in DC circuits. Although both devices operate on a similar principle — safely discharging transient overvoltages to the ground — they differ significantly in design, rated voltage, and performance characteristics because of the different electrical behaviors of AC and DC power.
In short, an AC SPD is designed to protect AC power systems, while a DC SPD is designed to protect DC power systems. Choosing the correct type ensures reliable surge and lightning protection for your electrical network.
|
Direct lightning stroke |
Indirect lightning stroke |
Indirect lightning stroke |
|
|
IEC 61643-1:2005 |
Class I test |
Class II test |
Class III test |
|
IEC 61643-11:2011 |
Type 1 / T1 |
Type 2 / T2 |
Type 3 / T3 |
|
EN 61643-11:2012 + A11:2018 |
Type 1 / T1 |
Type 2 / T2 |
Type 3 / T3 |
|
VDE 0675-6-11 |
Class B |
Class C |
Class D |
|
Type of test wave |
10/350 μs |
8/20 μs |
1.2/50 μs + 8/20 μs |
|
Terminology |
Iimp – Impulse discharge current (kA) |
In – Norminal discharge current (kA) Imax – Maximum discharge current (kA) |
Uoc – Open-circuit voltage (kV) |
Note 1: There exists Type 1+2 Surge Protection Device (SPD) combining the protection of loads against direct and indirect lightning strokes.
Note 2: Some Type 2 Surge Protection Devices can also be declared as Type 3 SPD.
This is the A.C. or D.C. voltage above which the SPD becomes active. This value is chosen according to the rated voltage and the system earthing arrangement.
This is the maximum voltage across the terminals of the SPD when it is active. This voltage is reached when the current flowing in the SPD is equal to In.
The voltage protection level chosen must be below the overvoltage withstand capability of the loads.
In the event of lightning strokes, the voltage across the terminals of the SPD generally remains less than Up.
This is the peak value of a current of 8/20 µs waveform that the SPD is capable of discharging minimum 19 times.
Why is In important?
In corresponds to a nominal discharge current that an SPD can withstand at least 19 times: a higher value of In means a longer life for the SPD, so it is strongly recommended to choose higher values than the minimum imposed value of 5 kA.
Type 1 SPD
This is the peak value of a current of 10/350 µs waveform that the SPD is capable of discharging of discharging at least one time.
Why is Iimp important?
IEC 62305 standard requires a maximum impulse current value of 25 kA per pole for three-phase system. This means that for a 3P+N network the SPD should be able to withstand a total maximum impulse current of 100kA coming from the earth bonding.
Applicable only to the spark gap technology. This is the current (50 Hz) that the SPD is capable of interrupting by itself after flashover. This current must always be greater than the prospective short-circuit current at the point of installation.
Type 2 SPD
This is the peak value of a current of 8/20 µs waveform that the SPD is capable of discharging once.
Why is Imax important?
If you compare 2 SPDs with the same In, but with different Imax: the SPD with a higher Imax value has a higher “safety margin” and can withstand higher surge current without being damaged.
Type 3 SPD
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