Voltage surge protection device comprising selective disconnection means

A voltage surge protection device comprising:

• a disconnection device with electric contacts comprising:
• a first connecting electrode electrically connected with a first connecting strip,
• a second connecting electrode electrically connected with a second connecting strip,
• a third movable arc switching electrode electrically connected to the second connecting strip,
• an actuating mechanism designed to move the third movable arc switching electrode to cause permanent opening of the electric contacts,
• a surge arrestor connected in series between the third movable arc switching electrode and the second connecting strip,
• comprising at least a first thermal disconnector for protection against AC or DC short-circuit currents connected in series with the surge arrestor between the third movable arc switching electrode and the second connecting strip, said thermal disconnector comprising at least one fuse element extending through a passage gap between a first and second conducting radial wall inside an insulating side wall of an arc extinguishing chamber, said arc extinguishing chamber comprising at least one conducting separator secured inside the insulating side wall to define two pressure relief volumes,
• said thermal disconnector being out of circuit when an electric arc is switched between the first connecting electrode and the second connecting electrode;
• disconnection of said disconnector being performed when AC or DC short-circuit electric currents having a lower energy than a tripping energy threshold flow through the latter, said tripping energy threshold corresponding to the threshold above which electric surge currents of 10/350 or 8/20 type cause permanent opening of the electric contacts.