On the Gassing Behaviour of Synthetic Ester Under Arcing Faults

In this work, non and aged synthetic esters have been subjected to electrical arcing faults having different intensities. Open beaker thermal aging is performed at $125 ^{\circ}\mathrm{C}$ while the monitoring intervals include 250-aged, 500, 750, and 1000 hours. Arcing fault intensity is realized by performing a repeated number of flashovers in the bulk of the liquid. This includes 30, 60, 90, 120, and 150 repeated breakdowns followed by immediate DGA measurements. This allowed an understanding of the fault gassing behavior at different aging durations and different fault intensities. The degree of degradation is monitored by prominent aging markers, acidity, and interfacial tension in each case. The discussions include digesting the impact of fault gas with degradation at different fault levels and potential correlations for synthetic esters. Appropriate Duval triangle and Duval pentagon methods are used to verify the fault gas diagnostic prediction ability. The results obtained from this study showed that the intensity of the gassing tendency evolves with the degradation rate and is attributable to the intensity of the arcing fault.