The detection methods of surge protectors (SPDs) mainly include electrical performance testing, environmental adaptability testing, and safety testing. The following are specific detection methods:

1. Electrical performance testing
Nominal discharge current (In) detection
Test the tolerance of SPD under high current impact.
Use the impulse current generator to simulate lightning strikes or large current impacts in the power system to detect the discharge current capacity of SPD.
Maximum discharge current (Imax) detection
Detect the maximum discharge current that SPD can withstand under extreme conditions and evaluate its protection performance under extreme conditions.
Voltage protection level (Up) test
Measure the voltage protection level of SPD to ensure that it can limit overvoltage within a safe range.
A high-voltage generator is used to generate high voltage and test the voltage tolerance of SPD.
Residual voltage (Ures) detection
Residual voltage is the voltage value remaining after the SPD is impacted.
Use a fast-response voltage test device to detect the residual voltage value of SPD when it is working to judge its protection performance.
The lower the residual voltage, the better the protection performance of the device.
Response time test
The response time of the surge protector directly affects its protection performance.
Apply transient overvoltage through a high-frequency signal generator and measure the response time of the SPD to ensure its fast response capability.
Insertion loss test
Measure and record the insertion loss within the transmission application frequency range where the SPD is intended to be used.
Use a network analyzer to test and observe the output results of the S12 and S21 channels of the transmission channel or S-parameter network analyzer to determine whether it is qualified.
Return loss test
Measure the return loss using an introduction wire with a maximum length of 1m and a matching characteristic impedance.
Apply a signal to the SPD, measure the reflected signal reflected back due to impedance discontinuity at the terminal where the signal is applied, and measure and record the return loss within the transmission application frequency range where the SPD is intended to be used.
Bit error rate (BER) test
For digital transmission applications where the SPD is intended to be used, use the maximum pseudo-random bit pattern for testing.
First measure the BER with the SPD in the test loop, then measure the BER without the SPD, and compare the difference between the two.
2. Environmental adaptability test
Insulation resistance test
Use an insulation resistance meter to measure the insulation performance of the SPD under different environmental conditions (such as humidity or high temperature) to ensure its safety in long-term use.
Lightning resistance test
Simulate the high voltage shock generated by lightning to test the lightning resistance of the SPD.
Aging test
Simulate the aging process of the SPD in long-term use to test its durability and stability.
Use environmental experimental equipment to conduct accelerated aging tests to evaluate its service life.
Environmental adaptability test
Under different environmental conditions such as high temperature, low temperature, and humidity, detect the performance changes of the SPD to ensure its stability in different environments.
3. Safety test
Leakage current test
Use a precision ammeter to measure the leakage current value of the SPD in the working state, evaluate its impact on the power grid system, and ensure its safety and stability to the power grid system.
Appearance and installation inspection
Check the appearance of the SPD. The surface should be flat, and smooth, without scratches, cracks, burn marks, or deformation.
Check whether the installation position and equipotential connection position of the SPD are at the junction of each lightning protection zone, and whether the installation position, quantity, model, main performance parameters and installation process of each level of SPD meet the design requirements of the drawings.
In summary, the detection methods of surge protectors (SPDs) cover many aspects, including electrical performance testing, environmental adaptability testing, and safety testing. These detection methods can evaluate the performance and quality of SPDs from multiple dimensions to ensure their reliability in real application scenarios.