Overvoltage arrester with two spark gaps - has tubular insulator divided by hollow-cylindrical mid electrode surrounding auxiliary spark gap electrodes

摘要

Two electrodes are mounted opposite each other in a gas-tight housing, thus forming a secondary spark gap. The electrodes are inserted into the ends of a tubular insulator which is divided by a hollow cylindrical mid electrode which surrounds coaxially the two electrodes, forming with them two main spark gaps. A ceramic disc is inserted into the mid electrode, which protrudes into the auxiliary spark gap. One side of the disc is coated with igniting strip of conductive material, which may be spaced from or conductively connected to the midlectrode, radially over the disc. All electrodes are provided with a layer of activating material in the region of the main spark gaps.