Metal-oxide arresters (MOA) protect primary equipment from overvoltage. HUWOR’s surge arrester monitoring white paper covers two complementary technical routes – passive energy-harvesting meters and core-through zero-flux sensors – with differentiated selection and power-supply schemes for substation and transmission-line scenarios.
Two routes, one purpose
- Route 1 – meter-type passive (HMJ1011-WBQ): series-connected into the grounding loop, self-powered from leakage current (starts at 100 uA, transmits at 200 uA); wireless LoRa or wired; IP67, -45 to +85 C; design life 16+ years; accuracy < 0.1% measured by Jiangsu EPRI / Xi’an HV Research Institute. The break-through choice for outage-free batch retrofits.
- Route 2 – core-through zero-flux (active): one-turn core-through without breaking electrical continuity, three-layer shielding; 35 kV – 1000 kV (including UHV); total current 0.1 mA – 1000 mA; per DL/T 1432.1/3.
Substation vs line: selection rule
Substation arresters are gapless with continuous leakage current – self-powering applies. Line arresters are generally gapped (EGLA) with no continuous leakage current – self-powering does not apply; line-side solutions must use solar/battery supply and public 4G/NB-IoT backhaul, monitoring lightning operation counts with time stamps.
Field track record
Deployed in 7 x 500 kV substations in Shandong (33 + 24 units) and Jiangsu Taizhou 220 kV Gaozhuang substation; 2026 State Grid Sichuan / Jiangxi framework awards and 2025 consecutive CSG framework awards.
Download the full white paper (PDF) – or browse all HUWOR white papers and technical resources.
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HUWOR Surge Arrester Monitoring Products
HUWOR supplies the Surge Arrester Leakage Current Sensor and the Smart Lightning Arrester Leakage Current Sensor for online MOA resistive current tracking. OEM/ODM supply is supported for utilities and system integrators.