Abstract: An array of SQUID detectors to map the magnetic field associated with test currents flowing in the component to be tested. The SQUID is an ultrasensitive, miniature device that transduces a faint magnetic field to a measurable voltage. Perturbation occurs in the test currents and the associated magnetic field at physical defects or inhomogeneities. Multi-dimensional test currents are injected into the component being tested; the injection being made between specific electrodes by varying the direction of the current until it is normal to the direction of the defect to maximize and amplify the effect of the perturbation. The perturbation is detected by the SQUID grid which pinpoints the location, orientation, and size of the defect. The frequency of the injected current can be made to sweep the spectrum from DC to the highest response limit of the SQUID to scan for defects at various depths.

Abstract: A stab type isolating connector for offset joints in enclosed high voltage electric bus apparatus comprises a removable contact rod for connecting laterally offset terminal ends of linear bus conductors within an enclosing sheath. The contact rod is slidable through a transverse passage in one terminal end into and out of engagement with a contact socket in the other terminal end, making contact with both terminal ends in its fully engaged position. Preferably the contact rod is tubular and slides over a guide rod secured within the contact socket. The guide rod may be sectional so that after seating of the contact rod a section of the guide rod may be used to secure the contact rod in engaging position.

Abstract: A sectionalized horizontal enclosing sheath for high voltage, gas-insulated electric bus apparatus comprises axially adjacent sheath members in spaced-apart relation connected by an annular coupling band. Juxtaposed ends of the band cooperate with the spaced apart sheath members to define an elongated transverse aperture in a bottom wall of the sheath and between the coupled sheath members. A box-like receptacle for trapping free conducting particles within the sheath is affixed over the aperture externally of the sheath.

Abstract: A tubular metallic sheath for horizontally disposed enclosed electric bus apparatus includes a corrugated bellows section having at one end a terminal convolution forming in internal annular recess. A sheath portion axially adjacent the recess, which may be a substantially tubular end portion of the bellows, is axially flared toward the annular recess. Within the bellows in coaxial radial spaced relation is mounted a metallic sleeve fixed at one end and axially flared toward a free end which is disposed in radial spaced relation within the oppositely flared adjacent sheath portion. The sleeve serves to shield the corrugated portion electrostatically so that the terminal convolution constitutes an effective particle trap. The bottom surfaces of the sleeve and the sheath portion adjacent its free end provide a stepped passageway for leading loose particles into the trap.

Abstract: Gas-filled enclosed electric bus apparatus having an enlarged spherical elbow joint is provided with a joint housing having a deep particle trap directly beneath the spherical joint and at least one narrow entrance slot in the housing bottom wall. Each slot extends transversely of the longitudinal axis of a horizontal conductor connected at the joint and the housing bottom wall is inclined in all directions toward the trap.

Abstract: Enclosed gas-insulated electric bus apparatus especially designed for use in horizontal disposition with high unidirectional system voltage includes deep trench-like electrostatic particle traps and inclined ramps leading to the traps. A method for entrapping such particles prior to the application of system voltage comprises preliminary imposition of an alternating conditioning voltage of relatively low magnitude from a low power source, preferably in steps of increasing magnitude.

Abstract: In this method, a pre-formed insulating sleeve is placed about the adjacent ends of the two sections of high voltage cable that are to be joined. At opposite ends of the sleeve in locations between the sleeve and the original cable insulation, two rings of porous material are provided. Into the space between the sleeve and the surrounded cable portion, there is pumped a slurry containing suspended particles of insulating material. The liquid component of the slurry is allowed to discharge from said space via the pores in said rings, but the particles of insulating material are filtered out so as to build up a deposit of said particles from the internal surfaces of said rings. This pumping and filtering action is continued until the deposit fills the space between the sleeve and the surrounded cable portion.

Abstract: In the disclosed method of applying electrical insulation, a housing with a porous wall is placed around a conductor in spaced relationship thereto, and a slurry is pumped into the space between the housing and the conductor. This slurry comprises a liquid and particles suspended in the liquid having good electrical insulating properties. The liquid component is allowed to discharge from the housing via its pores, but the solid particles are filtered out within the housing so as to build up from the internal surface of the housing a deposit of the particles. This pumping and filtering action is continued until the space between the housing and the conductor is substantially filled with the deposit.