Gas-insulated low- or medium-voltage load break switch

A gas-insulated low- or medium-voltage load break switch, comprising:

• a housing defining a housing volume for holding an insulation gas at an ambient pressure p0;
• a first arcing contact and a second arcing contact arranged within the housing volume, the first and second arcing contacts being movable in relation to each other along an axis of the load break switch and defining a quenching region in which an arc is formed during a current breaking operation;
• a pressurizing system having a pressurizing chamber arranged within the housing volume for pressurizing a quenching gas to a quenching pressure pquench during the current breaking operation, wherein the quenching pressure pquench and the ambient pressure p0 satisfy a relationship p0<pquench;
• and
• a nozzle system arranged within the housing volume for blowing the quenching gas in a subsonic flow pattern from the pressurization chamber onto the arc formed in the quenching region during the current breaking operation, wherein the load break switch is designed for maintaining the subsonic flow pattern during current breaking operations,
• the nozzle system comprises at least one nozzle arranged for blowing the quenching gas from an off-axis position predominantly radially inwardly onto the quenching region, and
• the insulation gas comprises a background gas in a mixture with an organofluorine compound selected from the group consisting of:
• fluoroether, oxirane, fluoroamine, fluoroketone, fluoroolefin, fluoronitrile, and mixtures and/or decomposition products thereof.