CASTING METHOD FOR PRODUCING A PROTECTIVE SHEATH AROUND A SURGE ARRESTER AND A CASTING MOULD THEREFOR

摘要

The invention relates to a casting method for producing a protective sheath (20) around a surge arrester (1), which has a cylindrical discharge element (4) arranged between two end armatures (3) and a plurality of retaining rods (5), which are clamped into the end armatures (3) and surround the discharge element (4). The casting method comprises the steps: - placing the surge arrester (1) into a first mould (10); - pouring a casting compound around the surge arrester (1) in order to mould on a supporting part (30), the inside of which nestles cylindrically around the discharge element (4) and the outside of which nestles in a fillet-shaped manner around each of the retaining rods (5); - curing the casting compound to fix the retaining rods (5) with respect to each other and with respect to the discharge element (4); - removing the surge arrester (1) with the supporting part (30) moulded thereon from the first mould (10) and placing it into a second mould; - pouring casting compound around the surge arrester (1) with the supporting part (30) moulded thereon in order to form a shield part (31), which has the external shape of the protective sheath (20); - curing the casting compound. The invention furthermore relates to a casting mould as the first mould (10) for a casting method, which has first recesses (11) for receiving the retaining rods (5) of an inserted surge arrester (1), said recesses each nestling in a fillet-shaped manner around the retaining rods (5). The advantage of the casting method and casting mould according to the invention lies in that the retaining rods and the discharge element are fixed by a supporting part moulded on during the first casting process and therefore can no longer be bent or displaced with respect to each other during the subsequent casting process.