The risk of the housing bursting and splitting in case of an arrester overload for the
design shown in Figure 15, is nonexistent. The arc resulting from a puncture or a flashover
of the MO resistors rips the silicone rubber housing open, and with almost no resistance,
finds its way outside.
The advantages of such an arrester design have only been hinted upon here. The
combination of the given weight reduction in comparison to a porcelain housing, the
ease of handling during transportation and installation, and last but not least, the savings
in cost that manufacturing such an arrester offers in comparison to an arrester with porcelain
housing, present advantages which make it clear why the polymer-housed arresters
within the medium voltage range have become so popular. As a result, it is also
apparent why the devices with porcelain housings have, in this case, virtually disappeared
from the market.