Water solution in high-voltage dielectric liquids

IT HAS long been recognized by the practical engineer responsible for the proper maintenance of high-voltage oilfilled electrical equipment that water constitutes one of the chief and in some instances the only serious threat to successful service. However, consideration of the dangers presented by water during the operation of high-voltage machines must not be limited to a study of the relation between the dielectric strength and the water content of the insulating liquid used. For successful operation, the cellulosic insulation must be maintained in a dry condition.