ZTZ’s Technical Expertise

A transformer H2 bushing showed temperature dependable feature power factor (PF), with higher PF at higher temperatures at Summer time. ZTZ’s offline Doble testing confirmed the issue (PF increase from initial 0.28% to 0.98%), and their post-replacement analysis identified subtle defects invisible to initial online trends. This forensic expertise guided the root-cause diagnosis, preventing recurrence. 

Evidence of Monitoring Use

Continuous BMS trending captured the PF escalation in a time-series chart (H2 in red, rising sharply to 1.5% over months), triggering the offline test. Images of the ripped-up core showed initial PD traces, validating the monitor’s sensitivity to early insulation breakdown and enabling targeted replacement without full transformer failure.