Relationship between bushing failure and transformer failure is discussed and, in regard of that,
two bushing failure types are recognized: incipient bushing failure that does not result in transformer
damage and terminal bushing failure having transformer failure as a consequence. It can be seen, that
without applying the diagnostics, all bushing failures are terminal. Thirteen bushing failures have been
analyzed regarding their cause, failure mechanism and consequences. In that sense, the ability and
limitation of off line and on line diagnostics are discussed and some improvements are proposed. Some
switchyard properties in the aspect of fire protection are indicated and, especially, the possible influence
of rigid tubular connections on bushing failures. Beside mentioned design, service, condition diagnostics
and other properties of all three condenser types of bushings are described in the paper
