Abstract: A capacitive signal coupler for use with a large dynamoelectric machine for coupling signals indicative of corona discharge from the stator bars to a monitor system is combined with an end cap made to fit over the connector extending between two stator bars. The end cap has a high voltage capacitor encapsulated in its walls. One lead from the capacitor is fastened to the connector with a screw before the end cap is installed. The other lead projects from the end cap and is connected to one terminal of a high voltage fuse. The fuse is secured to the end cap. The other terminal of the fuse is adapted to be connected to a cable leading to a monitor system. The coupler is preferably fastened to the lower end of the conductors of a vertical dynamoelectric machine where there is a full range of choice of location in the circuit voltages from line to neutral in two bar steps. The end cap is epoxy sealed in place to make an installation requiring little more space than the installation of a normal end cap.

Abstract: According to the invention, electrically conductive paths are formed between the coil armor and the core laminations of dynamoelectric machines for inhibiting corona. This is achieved by injecting an uncured, semi-conducting, elastomeric material between the coil sides and the walls of the core slots by way of the air ducts in the core, and thereafter curing the material. The uncured material has a viscosity which enables it to be forced under pressure between the coil sides and slot walls by means of a pneumatically actuated gun assembly whose construction and operation are described in detail. The cured material has a resistance high enough not to form eddy current paths between laminations and yet low enough to conduct charge from the coil armor to the core. It is also capable of retaining its strength, elasticity, conductivity, etc., and remaining in place between the coils and core under vibrations, coolant flow, electric stresses, repeated temperature changes, etc.

Abstract: According to the invention, electrically conductive paths are formed between the coil armor and the core laminations of dynamoelectric machines for inhibiting corona. This is achieved by injecting an uncured, semiconducting, elastomeric material between the coil sides and slot walls through the use of an injector tool inserted between them, and thereafter curing the material. The uncured material has a viscosity which enables it to be forced under pressure into these spaces, and when cured it has a resistance high enough not to form eddy current paths between laminations and yet low enough to conduct charge from the coil armor to the core. It is also capable of retaining its strength, elasticity, conductivity, etc., and remaining in place between the coils and core under vibrations, coolant flow, electric stresses, repeated temperature changes, etc., for the normal operating life of the machine.

Abstract: According to the invention, electrically conductive paths are formed between the coil armor and the core laminations of dynamoelectric machines for inhibiting corona. This is achieved by injecting an uncured, semiconducting, elastomeric material between the coil sides and slot walls through the use of an injector tool inserted between them, and thereafter curing the material. The uncured material has a viscosity which enables it to be forced under pressure into these spaces, and when cured it has a resistance high enough not to form eddy current paths between laminations and yet low enough to conduct charge from the coil armor to the core. It is also capable of retaining its strength, elasticity, conductivity, etc., and remaining in place between the coils and core under vibrations, coolant flow, electric stresses, repeated temperature changes, etc., for the normal operating life of the machine.

Abstract: According to the invention, electrically conductive paths are formed between the coil armor and the core laminations of dynamoelectric machines for inhibiting corona. This is achieved by injecting an uncured, semi-conducting, elastomeric material between the coil sides and the walls of the core slots by way of the air ducts in the core, and thereafter curing the material. The uncured material has a viscosity which enables it to be forced under pressure between the coil sides and slot walls. The cured material has a resistance high enough not to form eddy current paths between laminations and yet low enough to conduct charge from the coil armor to the core. It is also capable of retaining its strength, elasticity, conductivity, etc., and remaining in place between the coils and core under vibrations, coolant flow, electric stresses, repeated temperature changes, etc., for the normal operating life of the machine.

Abstract: According to the invention electrically conductive paths are provided between the coil armor and the core laminations of dynamoelectric machines by placing a semiconducting elastomeric material between the coil sides and the walls of the core slots. The elastomeric material is of a type which has a controlled resistance and will deform sufficiently under pressure to flow into the irregularities between the coil side and the slot walls, and in so doing provide conductive paths for electric charge to flow from the armor to the core laminations. This material must be capable of retaining its strength, elasticity, conductivity, etc., and remaining in place between the coils and core under vibration, coolant flow, electric stresses, repeated temperature changes, etc., for the operating life of the machine. Preferably, these paths will be heat conductors as well.