Abstract: Electrical insulation materials containing a synergistic mixture of either a metal acetylacetonate and a dicyclopentadienyl metal compound, a chromium salt and a dicyclopentadienyl compound, or a chromium salt and a metal acetylacetonate have unexpectedly high levels of corona resistance. The insulation materials preferably are prepared by dissolving the synergistic mixture in an organic resin such as an epoxy resin and then curing the resin.

Abstract: Methods and apparatus that improve flashover voltage levels in turbine-generators, and reduce the spacing between the end portion connections of one phase group and the end portion connections of neighboring phase groups provide a semiconducting layer on the inside surfaces of insulation that surrounds such stator coil connections. At least one of the metallic connectors which join the end portions in each phase group is electrically coupled to this semiconducting layer, such that discharge between the metallic connector and the insulation surrounding its associated phase group are prevented.

Abstract: An improved method and apparatus for preventing electrical shorts between sets of stator coil headers and accompanying connections is disclosed in which a reinforced, non-conducting cover is fitted over a pair of stator coil headers, or a stator coil header and an adjacent phase connector. Thereafter, the cavity formed by the fitted cover can be filled with an insulating, solidifying or polymerizing material or resin. Use of such an apparatus insulates the entire header apparatus and prevents any accidental shorting between sets of stator coil ends.

Abstract: A plurality of connector members are provided, each of which is shaped to fit between two adjacent strands in a column of strands on a stator winding (i.e., by manual insertion). Each connector member has a first side provided with an electrically conductive material and a second side provided with an electrically insulating material. An electrically conductive lead is electrically connected to the electrically conductive material on an associated connector member. In this manner, a plurality of electrically conductive leads are connected to an associated plurality of connector members. A plug or receptacle is provided at the opposite end of the electrically conductive leads with respect to the end connected to the connector members. Securing means are provided for pressing the strands against the connector members interposed therebetween in order to insure a conductive connection between each strand and the conductive material of a connector member.

Abstract: A double ring and radial lead assembly for electrically connecting the exterior and interior of a large, hollow shaft. A first ring secured to the shaft has a radial opening therethrough in general alignment with a radial opening in the shaft between its exterior surface and its interior surface. The first ring is secured to the shaft through an interference fit. An electrical conductor is arranged in the generally aligned openings and is secured in such position. A second conductive ring is attached to the first ring through an interference fit and covers the radially outer end of the radial lead. The second ring acts as a slip ring and provides a rotatable electrical contact surface for maintaining electrical connection with a stationary electrical source. The radially directed conductor and both rings are electrically insulated from the shaft.

Abstract: A method is provided for detecting the presence of arcing faults in the stator windings of large dynamoelectric machines, such as turbine generators. Arcing faults, such as broken strands in a winding conductor with continued arcing, give rise to high frequency currents which flow in the neutral lead of the generator winding. The presence of the arcing fault can thus be detected by observing the high frequency neutral currents and monitoring them for the presence of the characteristic frequency distribution resulting from the resonance characteristics of the current path.

Abstract: Apparatus for sensing overheated electrical insulation through the detection of thermoparticulates in a dynamoelectric machine's cooling gas system is disclosed. The cooling gas as it circulates will entrain thermoparticulates produced in the system when there is overheating. This gaseous carrier is then withdrawn and conducted to an ionization chamber where it is ionized. Downstream from the ionization chamber there is placed a first ion collector for collecting ions with relatively small radii. A second ion collector which is biased for collecting ions with relatively large radii is also placed downstream from the ionization chamber. By comparison of ion current from the first ion collector with ion current from the second ion collector it is possible to detect the presence of thermoparticulates in the cooling gas relatively independent of gas pressure, flow rate through the monitor, and effectiveness of the radiation source.

Abstract: A sampling system monitors a gas stream of a power generator and automatically samples the gas stream if its characteristics indicate that a material in the power generator is being thermally degraded. A gas stream monitoring device generates a first signal if it detects degradation occurring. A time-delay relay determines whether the first signal is continuous, and if it is the relay acts to prevent the monitor from monitoring the gas stream. If the first signal then terminates, a second signal is generated which activates an alarm and permits gas to flow into a sampling device. The sampling device has three sections which collect large particles, small particulates, and vapors and gases. The products collected can be analyzed to determine which material in the power generator was thermally degraded.

Abstract: A conductor is provided for large dynamo-electric machines, such as turbine generators, having a header at the end of the conductor for connection in a liquid-cooling system and having means for strengthening and reinforcing the conductor in the region immediately adjacent the header to reduce the excessive strains which may occur in this region and greatly reduce the possibility of failures of the conductor or of individual strands of the conductor.