Safety measures: Confirm that the arrester is operating normally (maintain a safe distance during live testing). Note: Most modern calibrators support live testing (because the counter itself is connected in series in the grounding loop, and the instrument is connected in parallel across the counter to inject current, which mainly flows through the counter coil without affecting the arrester body). However, always comply with on-site safety regulations and wear insulating gloves if necessary. Record initial value: Record the current reading of the counter under test (take a photo for documentation). Wiring: Clamp the instrument's high-voltage output terminal (red clip) onto the upper end of the counter (connected to the arrester side). Clamp the instrument's grounding terminal (black clip) onto the lower end of the counter (connected to the ground grid side). Note: At this time, the instrument is actually connected across the counter, simulating current flowing through the counter. Set parameters: Set the output current value (usually initially set to 500A or 1000A, depending on the counter type). Set the number of tests (e.g., 1 time). Execute the test: Press the "Test" button, the instrument emits a "beep" sound and discharges. Observe whether the on-site counter operates (digit wheel jumps or number increases by 1). Verification and recording: If the counter operates and the reading increases by 1, it is qualified. If it does not operate, gradually increase the current and test again until the starting current value is found. If it still does not operate after exceeding the rated value, it is judged as faulty. Record the test results via APP or paper. Restoration: Remove the test leads and clean up the site. 6. Common issues and precautions Counter not operating: Reason 1: Output current does not reach the starting threshold (try increasing the current). Reason 2: Internal mechanical jamming or coil burnout in the counter (needs replacement). Reason 3: Poor contact of test leads (check the clips). Counter misoperation/random operation: Usually caused by internal moisture, component aging, or strong electromagnetic interference. The calibrator cannot repair it; replacement is needed. Safety of live testing: Although it is safe in principle, testing is strictly prohibited during thunderstorm weather, when the arrester leakage current is extremely high, or when a ground fault occurs in the system. Test leads must have good insulation, and operators must not directly touch the metal parts of the counter. Waveform matching: Do not use DC power or ordinary AC power to "try" the counter, as this not only fails to verify its lightning action characteristics but may also burn out the internal nonlinear components. A dedicated impulse current calibrator must be used. 7. Reference for mainstream brands in the market International brands: Haefely (Switzerland, now part of Power Diagnostix, high-end benchmark), Omron (Japan, some models). Leading domestic brands: Wuhan Ultra-High Voltage Electric Power: Complete product line, high cost-effectiveness, high bid-winning rate in domestic power grids. Wuhan Musen Electric: Good at lightweight handheld devices. Shanghai Siyuan Hongrui: High integration, often paired with arrester online monitoring systems. Baoding Tianwei/Xinnuo: Commonly used in northern regions. 8. Special tips Regular calibration: The calibrator itself is a measuring instrument, and it is recommended to send it annually to a provincial metrology institute or a qualified laboratory for calibration to ensure the accuracy of its output current. Data correlation: In modern smart grids, lightning counter data is gradually being linked with lightning location systems and arrester online monitoring devices. Calibration is not just about checking the digit wheel, but also about verifying the reliability of the entire lightning protection data collection chain. If you need to know about special testing methods for specific voltage levels (such as 500kV GIS arrester counters) or need to interpret specific calibration report data, please feel free to ask.
