Zareba 5000‑B is a high‑power AC electric fence charger designed to deliver up to 100 mile range and equipped with a Storm Guard feature for lightning protection. Common failure points in this class of energizers include degraded power supply components (transformer, rectifier), insulation breakdown between the output phase and chassis, and malfunctioning storm guard circuitry that can short or open under surge conditions.

First‑check diagnostics: verify input voltage and continuity to the transformer; measure DC output voltage and joule count across the fence line; inspect the Storm Guard relay and fuse for integrity; and perform an insulation resistance test between the energized phase and chassis ground.[oss-gpt-20b]