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.
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.
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.
SPD Definition
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.
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/
SPD Types
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:
Understanding the various SPD kinds and the corresponding applications is made easier by the table below:
| Surge Protective Device Types | Category | Description | Waveform | Applications |
| Type 1 | Primary | Install in the primary distribution board at the origin of the electrical | 10/350μs | Critical infrastructure, healthcare facilities, data centers, high lightning frequency areas |
| Type 2 | Secondary | Install at the sub-panel or Distribution board level. They provide protection against surges that may have passed through a Type 1 SPD but can still cause damage to sensitive electronic equipment. | 8/20μs | Residential & commercial applications |
| Type 3 | Point-of-use | Protect individual electronic devices plugged into a wall outlet. Type 3 SPDs are typically built into power strips or plug-in surge protectors | combination of voltage waves (1.20/50μs) and current waves (8/20μs) | Power strips, plug-in surge protectors, electronic devices |
Common characteristics
Surge protective devices (SPDs) have a number of features in common that make them efficient at shielding electronic equipment from power surges.
Uc: Maximum continuous operating voltage
Up: Voltage protection level
In: Nominal discharge current of Type 2 SPDs with 8/20 μs waveform.
Imax: Maximum discharge current of Type 2 SPDs with 8/20 μs waveform.
Iimp: 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/
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 | In (80/20μs) | Imax (8/20μs) | Iimp (10/350μs) | Uoc (1.2/50μs) |
Type 1 | Class I | 25 kA | 100 kA | 25 kA | / |
Type 1+2 | Class I+II | 20 kA | 50 kA | 7 kA | / |
12.5 kA | |||||
Type 2 | Class II | 20 kA | 40 kA | / | / |
Type 2+3 | Class II+III (or III) | 10 kA | 20 kA | / | 20 kV |
5 kA | 10 kA | 10 kV |
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.
Response Time
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/
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:
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.
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.
Our reliable surge protection solutions — proven by real customer success.
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