If The Surge Arrester Casing Is Damaged, The Internal Valve Plate Will Be Instantly Punctured

A damaged lightning arrester housing leads to instant internal valve breakdown because moisture ingress radically distorts the internal electrical field. When the polymer or porcelain seal fails, ambient humidity enters the housing, creating a conductive path across the zinc oxide varistor disks. This causes immediate thermal runaway and dielectric failure during normal grid operations.

How Housing Failure Impacts Different Grid Voltages

Line degradation manifests rapidly across various network thresholds, making early detection vital for grid stability. For instance, a cracked 12kv surge arrester often experiences a complete flashover during routine switching operations due to internal moisture tracking.

Higher voltage installations face even severe degradation patterns:

• A compromised 120 kv lightning arrester will suffer catastrophic degradation within hours of seal loss.

• In transmission substations, a failed 132 kv lightning arrester triggers immediate circuit breaker trips.

• Environmental exposure on a 132kv lightning arrester accelerates internal tracking, leading to housing explosion.

• Voltage stress on a breached 132kv surge arrester causes localized arcing, destroying the varistor core.

Risk Matrix by Voltage Class

Actionable Field Procedures to Prevent Varistor Breakdown

To prevent sudden valve failure, maintenance crews must transition from reactive repairs to predictive diagnostic protocols. Implementing these specific field testing procedures ensures micro-cracks are identified before moisture causes an irreversible ground fault:

1. Deploy thermal imaging cameras during peak load hours to identify localized heating anomalies near the top seals.

2. Conduct regular third-harmonic resistive current measurements to detect early signs of internal varistor degradation.

3. Utilize high-resolution optical zoom cameras to inspect the sheds for hairline fractures or hydrophobic loss.