Serveron – The Importance of Measuring Oxygen In DGA

A Qualitrol Serveron TM8 mutli-gas DGA device was monitoring an old (30+ years) 3-phase 230kV shell-form nitrogen (N) blanketed GSU. At midday on November 16, 2017, the TM8 alarmed for increasing concentration of Oxygen (O2), which had been stable at 130ppm for an extended period. Over the course of the following 3 days O2 concentration continued to increase, peaking at 2,150ppm before gradually declining back to a stable 200ppm.
Reviewing the data around the time of the increase in O2 concentrations using Serveron TM View software, no fault is detected using any of the established diagnostic methods.

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