Shield Your Electronics: Leading Surge Protective Device Brands At LSP, we are trusted surge protection device manufacturers, delivering reliable solutions in the field of electrical protection devices since 2010. Our SPDs use premium materials and hold ISO9001, TUV, CB, and CE certifications. We guarantee fast delivery and consistent quality to meet global standards. From custom product designs and packaging to trusted components and flexible order quantities, we help our partners deliver safe, efficient, and certified electrical protection devices worldwide. Choose LSP — your reliable partner for smarter surge protection and electrical safety solutions. Stay Powered, Stay Protected – Our Surge Protective Device Series AC Surge Protective Devices are designed to be installed at the service entrance of low voltage systems or close to sensitive equipment to protect against transient overvoltages. DC surge protective device is isolated DC voltage systems with 600V 1000V 1200V 1500 V DC have a short-circuit current rating up to 1000 A. Explore FRD2, FRD4, and SRD2 series SPDs for reliable data line protection. PCB mounting surge protectors are designed to be directly integrated onto PCBs, providing reliable PCB surge protection for sensitive electronic components. Comprehensive Surge Protection Solutions for Multiple Industries Domestic/Off-grid Photovoltaic Energy Storage Systems Wind Turbine Installation Water Treatment Security Systems Radiocommunication Why Choose LSP As Your Surge Protection Supplier? We offer reliable surge protection solutions tailored to your needs, ensuring safety, stability, and long-term equipment performance. 99.99% Surge Protection Maximize Protection With Greater Precision and Improved Durability Leading LSP surge protective device manufacturer providing solutions for industrial electrical equipment safety across industries. We use MOVs supplied by LKD and GDTs from Vactech to ensure the stability and lightning protection effectiveness of our surge protectors. We use metal lead pins with a thickness of 0.8mm and a width of 8mm, capable of handling high electrical potentials without easily breaking. Our R&D team’s optimized low-temperature trip device and soldering process enhance the arc suppression and fire prevention capabilities of our surge protectors. We use enhanced flame-retardant plastic casings to ensure the flame resistance of our SPDs. We select high-quality brass, red copper, and phosphor bronze components to ensure corrosion resistance during sea transportation. Only surge protectors that meet our testing standards are approved for shipment. All surge protective devices are certified by TUV, CB, and CE. Introduction to Surge Protective Device What is Surge Protective Device? A surge protective device, also known as a surge protector or SPD, is designed to safeguard electrical components against surges in voltage that might happen in the electrical circuit. Whenever a sudden increase in current or voltage is produced in the electrical circuit or communication circuit as a consequence of outside interference, the surge protection device may conduct and shunt in a very short period of time, preventing the surge from damaging other devices in the circuit. Surge protective devices (SPDs) are a cost-effective method for preventing outages and enhancing system reliability. They are typically installed in the distribution panels and play an important role in ensuring the smooth and uninterrupted operation of electronic devices in a wide range of applications by limiting transient overvoltage. How Does Surge Protective Device Work? SPD Working Principle The basic principle behind SPDs is that they provide a low impedance path to ground for excess voltage. When voltage spikes or surges occur, SPDs work by diverting the excess voltage and current to the ground. In this way, the magnitude of the incoming voltage is lowered to a safe level that doesn’t damage the attached device. To work, a surge protection device must contain at least one non-linear component (a varistor or spark gap), which under different conditions transitions between a high and low impedance state. Their function is to divert the discharge or impulse current and to limit the overvoltage at the downstream equipment. Surge protection devices function under the three situations listed below. A. Normal Condition (absence of surge) In case of no surge conditions, the SPD has no impact on the system and acts as an open circuit, it remains in a high impedance state. B. During voltage surges In case of voltage spikes and surges, SPD moves to the conduction state and its impedance decreased. In this way, it will protect the system by diverting the impulse current to the ground. C. Back to normal operation After the overvoltage has been discharged, SPD shifted back to its normal high impedance state. To learn more about how SPD functions, please visit our webpage: https://lsp.global/how-does-surge-protection-work/ The Different Types of Surge Protective Devices There are three main categories of surge protective devices based on their level of protection defined by the current IEC 61643-11:2011/EN 61643-11:2012 standards: Type 1 / Class I / Class B Type 2 / Class II / Class C Type 3 / Class III / Class D Understanding the various SPD kinds and the corresponding applications is made easier by the table below: Common characteristics Surge protective devices (SPDs) have a number of features in common that make them efficient at shielding electronic equipment from power surges. U c : Maximum continuous operating voltage U p : Voltage protection level I n : Nominal discharge current of Type 2 SPDs with 8/20 μs waveform. I max : Maximum discharge current of Type 2 SPDs with 8/20 μs waveform. I imp : Impulse current of Type 1 SPDs with 10/350 μs waveform. You may choose the suitable surge protection for your unique needs by being aware of the various types and classifications of surge protectors, whether you need them for a large building, a distribution board, or a single device. For more information about SPD types, visit our webpage: https://lsp.global/surge-protection-device-types/ How to Choose the Ideal Surge Protective Device? Surge Protective Devices (SPDs) are essential components of electrical networks. However, choosing a suitable SPD for your system might be a difficult issue. Key considerations to keep in mind include the following: EN 61643-11:2012 IEC 61643-11:2011 Iimp (10/350μs) Class II+III (or III) Maximum continuous operating voltage (UC) The rated voltage of SPD should be compatible with the electrical system voltage to offer appropriate protection to the system. A lower voltage rating will damage the device and a higher rating will not divert transient properly. It is described as the time of SPD reacts to the transients. The quicker SPD responds, the better the protection by the SPD. Usually, Zener diode based SPDs have the fastest response. Gas-filled types have a relatively slow response time and fuses and MOV types have the slowest response time. Nominal discharge current (In) SPD should be tested at 8/20μs waveform and the typical value for residential miniature-sized SPD is 20kA. Maximum impulse discharge Current (Iimp) The device must be able to handle the maximum surge current that is expected on the distribution network to ensure that it does not fail during a transient event and the device should be tested with 10/350μs waveform. Clamping Voltage This is threshold voltage and above this voltage level, SPD starts to clamp any voltage transient that it detects in the power line. Manufacturer and Certifications Selecting an SPD from a well-known manufacturer that has certification from an impartial testing facility, such as UL or IEC, is crucial. The certification guarantees that the product has been examined and passes all performance and security requirements. Understanding these sizing guidelines will enable you to select the best surge protection device for your needs and guarantee effective surge protection. For additional information about choosing a single-phase or three-phase SPD, visit the website listed below: https://lsp.global/single-phase-surge-protector/ https://lsp.global/3-phase-surge-protector/ How To Install a Surge Protective Device? Installation Guide for AC SPD Single-phase Surge Protector in a Sub-distribution Box Three-phase Surge Protective Device in a Sub-distribution Box 1000V DC Solar PV Combiner Box with Surge Protective Device 1500V DC Solar PV Combiner Box with Surge Protective Device Installation Guide for DC SPD Installation Rules to Follow Despite how easy it is to install a surge protector in a power distribution system, it is crucial to follow the appropriate procedures to assure safety and reduce any potential dangers. Following these steps when installing an SPD in a distribution system: Turn off the power: Make sure to shut off the power before beginning any electrical repair and engage off-load isolator to avoid any unwanted event to occur. Installation location: Choose an appropriate location for the SPD. For best protection, the SPD should ideally be located as close as feasible to the main breaker. The surge protection device diagram from the manufacturer should be consulted for details on location requirements. Mount the SPD: Install the SPD in the desired location on the DIN rail. Verify that the mounting screws are firmly in place. Connecting to the earth connection: In accordance with the manufacturer’s recommendations, ground the SPD. Typically, this requires joining a ground wire from the SPD to the grounding bus bar. Test the SPD: Restarting the device after installing the SPD will let you to check that everything is working as it should. For details on particular testing techniques, consult the surge protection device installation manual or the designer’s instructions. Only electricians with a license or other technicians with the necessary education and training should install SPDs. To maintain continuous security, the SPD should also go through routine testing and maintenance. Our Continuous surge protective devices Improvement The Trusted Partner for Businesses Seeking Certified Surge Protective Device

We are among trusted surge protection companies, holding TUV, CB, CE, and ISO 9001 certifications. Our SPDs are tested to IEC/EN 61643-11 and IEC/EN 61643-31 standards. What Our Customers Say about LSP's Surge Protective Device Our reliable surge protection solutions — proven by real customer success. Alessandro Moretti Got Questions​ About LSP & SPDs? 1. What is an SPD and why is it important in industrial electrical equipment? An SPD (Surge Protection Device) protects electrical systems from voltage spikes caused by lightning or switching. It absorbs excess voltage and directs it to the ground, preventing damage to sensitive equipment. 2. What types of electrical protection devices does LSP offer? LSP offers Type 1, Type 2, Type 3, Type 1+2 and Type 2+3 surge protection devices for both AC and DC systems. We also supply specialized SPDs for wind turbines, data/data-over-Ethernet lines, PoE, LED lighting, PCB mounting, and DC combiner boxes. 3. What applications can LSP’s surge protection devices be used for? LSP’s SPDs are suitable for domestic and industrial photovoltaic systems, solar farms, energy storage, e-mobility, wind turbines, water treatment, security systems, agrivoltaics, data centers, LED lighting, and radiocommunication. 4. What makes LSP’s SPDs reliable electrical safety devices? LSP has focused on SPDs since 2010, with strict IEC/EN 61643-11 testing, high-quality LKD MOVs and Vactech GDTs, strong in-house R&D, custom designs, a 1,600 ㎡ certified factory and no MOQ. All SPDs pass surge, heat, salt spray and flame tests, come with fast lead times and a 5-year warranty — making them trusted for PV, wind, LED and more. 5. What is PV surge protection and why do you need it? PV surge protection means installing surge protection devices (SPDs) to prevent damage to solar panels, inverters, and storage systems caused by lightning strikes and grid surges. Without it, expensive PV equipment can fail, reduce output, or even cause fire risks, especially in large solar farms or off-grid installations. 6. Do EV Chargers Need Surge Protection? Yes. EV charger surge protection is essential because EV chargers are sensitive electronic devices that can be damaged by lightning strikes and power surges. Surge protection helps prevent equipment failure, fire risk, and costly repairs, making it essential for both residential and commercial charging setups. 7. What is lightning surge protection? Lightning surge protection refers to the use of specialized devices to safeguard electrical systems from voltage spikes caused by lightning strikes. These spikes can damage equipment, cause fires, or interrupt operations. Lightning surge protection devices (SPDs) are installed at key points in the power system to divert excess voltage safely to the ground, protecting sensitive equipment in homes, commercial buildings, and industrial facilities. 8. What does the surge protection device working principle involve? The surge protection device working principle involves detecting overvoltage surges and diverting excess energy safely to the ground using components like MOVs or GDTs. This helps protect electrical equipment from damage caused by lightning or power spikes. 9. What does a surge protection device wiring diagram typically show? A surge protection device wiring diagram typically shows how the SPD is connected between the power lines (L, N) and the ground (PE). It illustrates the correct installation position—usually at the main distribution board—and the wiring method for single-phase or three-phase systems to ensure proper protection and grounding. 10. How to install surge protection device in a residential or commercial electrical system? To install a surge protection device, first turn off the main power. Mount the SPD near the distribution board, then connect it to the incoming power lines and ground according to the wiring diagram. Ensure proper fuse or circuit breaker protection. Finally, restore power and check indicator lights for normal operation. 11. What is Transient Voltage? Basics In electrical distribution systems, transient voltages occur due to a sudden increase in the amplitude of the voltage or current of the circuit. It is also known as spikes or voltage surges. These voltage fluctuations can be caused by lightning strikes, switching operations, or the operation of large motors due to high inrush starting current or other equipment. One common type is a lightning transient, which occurs when lightning strikes nearby electrical lines or equipment. This can cause a sudden spike in voltage, which can damage equipment and cause power outages. Another type of transient voltage is called a switching transient, which occurs when a large electrical load is switched on or off. This can cause a sudden surge in voltage, which can damage nearby equipment. Therefore, surge protection equipment is required in electrical systems to lessen the effects of transient voltage, they redirect excess voltage away from the connected system. 12. Why Do We Need Surge Protective Devices? Surge protective devices (SPDs) are essential in protecting electronic equipment from the harmful effects of transient overvoltage that can cause damage, system downtime, and data loss. In many cases, the cost of equipment replacement or repair can be significant, particularly in mission-critical applications such as hospitals, data centers, and industrial plants. Circuit breakers and fuses are not designed to handle these high-energy events, making additional surge protection necessary. While SPDs are specifically designed to divert transient overvoltage away from the equipment, protecting it from damage and prolonging its lifespan. In conclusion, SPDs are essential in the modern technological environment. 13. Surge Protective Device Coordination Coordination between SPD & SPD Surge protective device (SPD) coordination refers to selecting and coordinating multiple SPDs, to ensure comprehensive protection against voltage surges in an electrical system. When it comes to coordination of surge protecting devices, keep the following points in mind: Coordination Devices Coordination between SPD & its disconnect circuit breaker or fuse In electronic circuits, if the surge protection device exceeds its limitation capacity, it may be destroyed by short-circuiting itself. SPDs along with circuit breakers or fuses are arranged in such a way as to minimize the risk of overvoltage and interference effects. It is essential for effective protection against overload caused by SPD degradation, high-intensity short circuits brought on by transient voltages, and low-intensity short circuits brought on by overload. A circuit breaker for SPD performs the following functions: Allows power to the surge protector to be removed without interrupting power to other loads. If a component fails inside the protector, only the circuit breaker will trip, and the power of any other load will not be disturbed. How do I match a surge protector to a circuit breaker? We list a table below for your general reference: 20-50kA (Type 2) 20-50kA (Type 2) 12,5kA (Type 1) 25-100kA (Type 2) 14. What Causes Surge Protective Devices (SPD) Failure? Surge protective devices (SPDs) are engineered to provide reliable protection against transient overvoltages, but certain factors can lead to their failure. Following are some of the underlying reasons behind SPDs failure: Excessive power surges One of the primary causes of SPD failure is overvoltage, overvoltage can occur due to lightning strikes, power surges, or other electrical disturbances. Make sure to install the right type of SPD after proper design calculations according to location. Due to environmental conditions including temperature and humidity, SPDs have a limited shelf life and might deteriorate over time. Furthermore, SPDs can be harmed by frequent voltage spikes. Configuration issues Misconfigured, such as when a wye-configured SPD is linked to a load that is connected via a delta. This may expose the SPD to greater voltages, which could result in SPD failure. Component failure SPDs contain several components, such as metal oxide varistors (MOVs), that can fail due to manufacturing defects or environmental factors. Improper grounding For an SPD to operate properly, grounding is necessary. An SPD can malfunction or possibly become a safety concern if it is improperly grounded. 15. How Much Are Surge Protection Devices? The cost of a surge protection device may vary depending on the elements mentioned in the subsection above, such as the device’s kind, the desired level of protection, and the application. The price range for AC SPDs typically lies between $10 and $150 per unit. The type, brand, and features of the particular device affect the pricing. It is critical to take the necessary amount of protection parameters into account while choosing an SPD. The highest level of protection is provided by a Type 1 SPD, however, it may cost more than a Type 2 SPD. There might be additional expenses of installation, other than the price of the item itself. To guarantee that the device is placed correctly and adjusted for maximum safety, it is crucial to make sure that the installation is carried out by a certified electrician. Despite the fact that initially they may appear to be an additional investment, the price of fixing or replacing broken equipment may be far more than the price of setting up an SPD. 16. Surge Protective Device Guidelines Surge Protective Devices (SPDs) play a critical role in protecting electrical and electronic equipment and to ensure proper protection, it is essential to follow guidelines for selecting and installing SPDs. Here are a few guidelines for using surge protective devices: Always select the suitable type of surge-protected device. As there are many types in the market. One should use the appropriate type as per the requirements to protect the devices connected with it. Always check the voltage, energy and current ratings of the SPDs. Avoid overloading effects to reduce the risk of failure of surge-protected devices. Never connect too many devices to handle the high risk involving it. Properly install the SPD device as per standard and protection measures Maintain and test the SPDs periodically to avoid the effects of wear and tear. It ensures its long life and reduces the end of service before time. For more information about surge protective device guidelines visit our webpage: https://lsp.global/surge-protection-devices-selection-guide/ Ensure Business Continuity, Safeguard Your Equipment Surge Protective Device AC Surge Protector DC Surge Protector Signal Surge Protector PV Combiner box Automatic Transfer Switch Domestic/ Off-grid Photovoltaic Industry Photovoltaic Energy Storage Systems Wind Turbiner Installation Material Matters Quality Control OEM Partnerships Package & Deliver Wenzhou Arrester Electric Co., Ltd. 5th FL, Bldg 2, No. 888 Liujiang Road, Beibaixiang, Yueqing, Zhejiang 325603 China info@lsp.global +86-18968826885 +86-18968826885 Copyright © 2010-2026 Wenzhou Arrester Electric Co., Ltd. All Rights Reserved. Get A Quote Now