Failures typically manifest as physical damage, abnormal heating, or significant increase in leakage current. In severe cases, explosions may occur or single-phase grounding faults may be triggered. These phenomena are often caused by internal varistor aging, seal failure allowing water ingress, or overvoltage impacts.
Failures can be attributed to external and internal factors. External factors include overvoltage stress exceeding design limits, harsh environments causing seal degradation and water penetration, and surface contamination-induced flashover. Internal factors primarily involve manufacturing defects (such as poor sealing or varistor inconsistency) and natural aging of varistor materials.
Early failures can be effectively detected through regular visual inspections, measurement of DC reference voltage (U1mA), and leakage current tests. Emphasis should be placed on establishing a full lifecycle management strategy: ensuring parameter suitability for operating environment during selection; strictly controlling sealing and connection quality during installation; implementing online monitoring to track leakage current changes during operation combined with trend analysis during outage tests; and timely replacement of aged or frequently activated arresters.
Surge arrester failure results from combined electrical, thermal, and environmental factors. Implementing a condition-based maintenance strategy focused on prevention can significantly enhance operational reliability and ensure grid safety.