Lightning-protection spark gap

A lightning-protection spark gap, comprising:

• a housing (G);
• a first electrode (3a), having a first outer side (Aa) and a first inner side (Ia), and a second electrode (3b), having a second outer side (Ab) and a second inner side (Ib), wherein the first electrode (3a) and the second electrode (3b) diverge from each other;
• wherein, between the first inner side (Ia) of the first electrode (3a) and the second inner side (Ib) of the second electrode (3b), an ignition region (Z) and a subsequent propagation region (L) for an arc are formed;
• wherein the housing (G) forms an arc chamber (LK), which is arranged between the first and second electrodes (3a, 3b) and which is delimited by a quenching chamber (4);
• and
• wherein, in the housing (G), at least one gas circulation channel (K1) is configured, by means of which a gas flow escaping from the quenching chamber (4) in the event of a lightning stroke can be returned to the arc chamber (LK) via at least one first cut-out (V1;
• V1′;
• V1″;
• V1′″) in the propagation region (L) of the first electrode (3a);
• characterized in that
• the first cut-out (V1;
• V1′;
• V1″;
• V1′″) is configured asymmetrically with respect to a longitudinal extension of the first cut-out (V1;
• V1′;
• V1″;
• V1′″) in the propagation direction of the arc;
• and
• the first cut-out (V1;
• V1′;
• V1″;
• V1′″), in the propagation direction of the arc, decreases from a first cross-section (Q1) of the first electrode (3a) to a minimum cross-section (QM) of the first electrode (3a) over a first distance (l1;
• l1′;
• l1″;
• l1′″), and increases from the minimum cross-section (QM) of the first electrode (3a) to a second cross-section (Q2) of the first electrode (3a) over a second distance (l2;
• l2′;
• l2″;
• l2′″);
• and
• the first distance (l1;
• l1′;
• l1″;
• l1″) is shorter than the second distance (l2;
• l2′;
• l2″;
• l2′″).