Dielectric characteristic of dichlorodifluoromethane (R12) gas and mixture with N 2 /air as an alternative to SF 6 gas

In this study, dichlorodifluoromethane (R12) gas and mixtures with nitrogen (N 2 ) andair at different pressures and mixing ratios have been investigated and showedgood alternative to gas in terms of high‐voltage application.Mixed gases contain R12 gas, they offer good dielectric properties andpossibility to be used in low‐temperature environment. Synergistic effects andself‐recoverability test have been performed. Dielectric strength underquasi‐uniform field showed in the order of air in alternating current (AC), directcurrent (DC) and impulse was examined. Mixture R12/N 2 (80/20%) couldreach over 0.90–0.95 times to that of gas at 50 lb/in 2 at AC andR12/air (70/30%) gives 0.80–0.90 to gas. R12 gas presents brilliantself‐recoverability. The optimal ratio to switch gas is R12/N 2 (80/20%) andR12/air (70/30%) is based on the authors’ experimental condition and setup.