Abstract: A hollow cathode discharge device loosely supported by a cathode lead-in 26 in a glass sleeve 32, the device including a ceramic shield 42 received in the rim 38 of the glass sleeve in freely slidable relation thereto, and maintained in position by holding means such as a mica disc 48 supported from the anode structure including an anode lead-in 30.

Abstract: A detector assembly for in-core nuclear reactor monitoring in which the wall thickness of the outer housing tube 26a and the wall thickness of the inner calibration tube 28a, taken together with the diameters of operating and non-operating elements 34a, 36a, 38 filling the annular space between the tubes and each having interior highly compacted mineral insulation, provide a total thickness dimension adequate to meet code primary pressure requirements for normal nuclear reactor in-core conditions, with the OD of the outer housing tube permitting passage of the assembly through most existing assembly guide tubes 18, and the ID of the calibration tube being adequate to receive movable detectors 48 of a larger, standard size, thus permitting use of in-place standard drive systems.

Abstract: A gas insulated transmission line has an inner conductor supported by insulators including a fixed insulator and a movable insulator with each having recesses in their outer portion having recessed metallic inserts therein of like configuration. The fixed insulator has disposed within the insert a base of an interconnection strap that extends along the sheath and is welded thereto. An insulating standoff button is further provided on the exterior of the base of the interconnection strap and presses against the outer sheath. An insert of the movable insulator contains a roller assembly. Preferably the roller assembly includes a substantially cylindrical roller of a semi-rigid insulating material that has edges bearing against the outer sheath and conforming to the configuration of the outer sheath by reason of deformation under load.

Abstract: A receptacle with a ground fault circuit interrupter has a load contact and housing configuration in which a varistor for electronics protection is disposed with pressure contact to adjacent spring fingers of the load contacts. Also, a pre-assembly of molded plastic carrier elements supporting a sensing transformer, grounded neutral transformer, trip solenoid, and hybrid electronic circuit as a unit is disposed within the housing.

Abstract: Apparatus for performing selective-pole trip determination is included in each protective relay of a current only monitoring protective relay system for protecting an electrical transmission segment of a power system network against faults. Current signals from the phases of the transmission segment are provided to a sequence network of the apparatus for conversion into positive and negative sequence component signals for each phase. A zero sequence component signal is also derived. A logic circuit is provided for each of the phases of the transmission segment and is governed by the corresponding sequence component signals and phase shifted variations thereof to detect a single-pole fault exclusively in the corresponding phase and generate a signal in response to the detection. An internal trip detection enables each phase logic circuit to generate its corresponding trip signal.

Abstract: Multiple turn coils are arranged with turn insulation around individual turns, group insulation around each of a plurality of groups of turns, and ground insulation around the entire coil half. This arrangement protects against a potential discharge between turns upon occurrence of a steep front impulse voltage.

Abstract: Programmed overcurrent protection control apparatus with selectable time-overcurrent operation to govern the interruption of current through at least one power line associated with either a ground phase or a power phase of a power system network is disclosed. A programmed processor is included to derive an overcurrent time-to-trip in accordance with sampled measurement current values of the power line and selected derivation constants stored in a memory look-up table. The derivation constants are selected from the look-up table based on derivation parameters which may be set and read by the programmed processor from time to time. The programmed processor utilizes the selected derivation constants to derive the time-to-trip over a number of predetermined time intervals during which the overcurrent condition persists.

Abstract: A segmented inner conductor of a transmission line has joints between the segments with a plug on one segment fitting into a socket on an adjacent segment. An electrostatic shield covers the joint and confines particles. Particular features have to do with simplifying the parts and their means of assembly for speed and economy including a plug end having a stop configured for easy assembly with the main portion of an inner conductor segment, a shield with a folded under portion over a bond joining the plug end to the inner segment main portion, spring loaded contacts holding the shield to the plug end, and use of a retaining ring, without bonding, to secure a ring of contact fingers to a socket end.

Abstract: An insulator for supporting the inner conductor of a gas insulated transmission line is configured so that its outer extremity is a simple blunt portion that fits loosely within a bearing block of insulating material of lower dielectric constant than the insulator itself so as to provide structural simplicity and improved performance through lessened breakdown susceptibility. A cylindrical particle trap ring formed of flexible metal sheet material is attached to the bearing block at locations spaced from the insulator.

Abstract: A collector housing over the collector and brush assembly of a dynamoelectric machine is provided with a special valve called a vacuum breaker for permitting by manual operation the alleviation of negative pressure within the housing while the machine is in operation so that the collector housing may be rolled back from its normal location for inspection and maintenance of the collectors and brushes.

Abstract: A transformer differential relay which includes apparatus for speeding up the detection of a power transformer internal fault condition to initiate breaker action which interrupts current through the transformer is disclosed. Presently, conventional transformer differential relays include a unit for each phase of the power transformer for detecting a potential internal fault in a respective transformer phase winding and for generating a signal to operate a set of breakers. This breaker operation is inhibited for current inrush conditions of the transformer. However, a processing time is associated with the detection of such a current inrush condition. Accordingly, the breaker operating signal must be delayed for at least this processing time in order for the inhibition to be effectuated. For the case in which there is no current inrush condition, the breakers remain delayed in operation from the inception of a true internal fault.

Abstract: An electronic sensing and triggering circuit including an integrated overvoltage protection circuit is used in conjunction with an energy storage capacitor as well as output transistors for providing a vigorous voltage pulse supplied through a current pulse transformer to the gate of an SCR in a brushless excitation circuit discharge circuit branch.

Abstract: An electronic protective relay which offers a very sensitive detection of a reverse power condition of a three-phase alternating current generator for the protection against generator motoring is disclosed. A current signal is generated from a current transformer coupled to one phase of the ac generator; and a voltage signal is generated from a potential transformer coupled across the one phase and another phase of the generator. A current input circuit is operative to maintain the phase angle between the voltage and current signals over a wide variation of input current, e.g. from one milliamp to 75 amperes. In addition, a phase-rectification type multiplier affords a relatively simple, but effective method for detecting the power flow direction of the generator. Once the power flow is determined to be in the reverse direction and above a preselected magnitude, a signal indicative of a potential generator motoring condition is geneated.

Abstract: The simultaneous straightening and insertion of tubular sleeves into damaged heat exchanger tubes is accomplished by passing a pre-bent tubular sleeve through a bending apparatus utilizing three forming rolls. One of the forming rolls can selectively be moved toward the other two to compensate for varying radii of curvature. The apparatus is equipped with a pneumatic or hydraulic cylinder capable of pulling the tubular sleeve through the bending apparatus in incremental steps. By simultaneously straightening and inserting pre-bent tubular sleeves into damaged heat exchanger tubes, the tubular sleeves can be inserted into damaged tubes which are in positions which would otherwise be impossible to be repaired by this method. This method effectively circumvents the proscription of straight tube insertions into damaged heat exchanger tubes from the quarter spherical chamber of the heat exchanger.

Abstract: A signal bypass apparatus for a power line distribution switch incorporates two portions that are electrically connected together in parallel with a power line switch. Each portion comprises a transformer that is connected electrically in parallel with an inductor. A capacitor is connected between the transformer and the inductor of each portion and the assembly is connected between one side of a power line distribution switch and ground. The other portion of the bypass apparatus is similarly configured and connected between the other side of the power line distribution switch and ground. In one embodiment, the bypass apparatus is electrically connected to a transceiver.

Abstract: A power spark gap for protection of electrical equipment against overvoltages and having high current handling capacity is provided consisting of two carbon electrodes each of a hemispherical configuration disposed within a porcelain housing and with vent holes in the electrodes permitting arc transfer to an inner sleeve of durable conductive material.

Abstract: A brushless dynamoelectric machine with a molded insulating control wheel having a rim on whose inner surface the rectifiers and other components of the starting control circuitry are directly mounted. Proximate the central hub of the control wheel is mounted a resistor wheel of metal having axial apertures in which are located cartridge heater-type resistors that are interconnected to provide the starting resistor of the control circuitry. The resistor wheel has external fins that aid in dissipating heat from the resistors and also blow air onto the components mounted on the wheel rim.

Abstract: A transceiver is provided with both voltage and current coupling to a three phase transmission line system. Each phase conductor is coupled to a common point which is connected in signal communication with an input to a receiver. Another input of the receiver is coupled to the neutral conductor of the power line system by an H-field coupler. A signal coupling unit is associated with the voltage couplers between the common connection point and the first receiver input. The receiver is provided with the capability of comparing the voltage signal with the current signal and selecting the stronger of the two. Therefore, the transceiver of the present invention is less adversely affected by standing wave problems since the voltage and current signals are out of phase and voltage nodes are associated with current antinodes and vice versa. Therefore, regardless of the location along the standing wave that the transceiver is located, the best signal available will be used for demodulation purposes.

Abstract: A disconnector for lightning arresters is provided that incorporates a gas cylinder with a dielectric gas such as carbon dioxide which will be released upon an excess current and result in the extinguishing of the arc in the disconnector spark gap prior to danger of shattering of the arrester housing.

Abstract: In a machine such as a turbine generator with a rotor whose end turns are covered by a continuous retaining ring, axial blocks and support blocks are used in an end turn bracing system with the axial block supported by the support blocks at intermediate locations and with openings through the axial blocks at those locations that have a greater axial extent than the support blocks and permit axial gas flow that avoids obstruction by the support blocks. The support blocks are provided of laminated material whose laminations run continuously throughout both major and minor legs of their L-shaped cross-sectional configuration to avoid delamination due to stresses encountered in operation.