Use of a mixture comprising a hydrofluoroolefin as a medium-voltage arc-extinguishing and/or insulating gas and medium-voltage electrical device comprising same

A process for electrically insulating and/or electrical arc extinguishing an electrical device, the process comprising enclosing a gaseous medium within an electrical device containing electrical components,

• wherein:
• the gaseous medium comprises a mixture comprising a hydrofluoroolefin with three carbon atoms, said mixture having a global warming potential (GWP) lower than the global warming potential of the hydrofluoroolefin;
• and
• the hydrofluoroolefin is present in the mixture at a molar percentage (MHFO) at least equal to 95% of the molar percentage M determined by the formula M=(PHFO/Pmixture)×100, in which Pmixture is a pressure of the mixture at 20° C. in the electrical device and PHFO is a pressure that at 20° C. is equivalent to the saturated vapour pressure (SVP) of the hydrofluoroolefin at a minimum service temperature (Tmin) of the electrical device.