A. B. Chance Company

Hubbell Limited

University of Missouri

Lloyd Ronald Beard

Melvin B Goe, Jr

Sterlin O Cochran

Bryant Haines

Charles Worthington

Jeffery Joseph Kester

David A Rhein

Gerald B Roberts

Thomas Jude Herrick

Allen Houpt Knepper

Parke Thompson, Jr

John A Schwartze

A fuse cutout insulator for use in power distribution systems includes three electrically conductive pieces spaced apart and encapsulated by a dielectric material. The conductive components include a top hood, bottom pin, and central pin. The central pin is generally tube shaped and includes an outwardly extending flange to facilitate attachment of the fuse cutout to a utility pole. The top hood and bottom hinge include the traditional components for operable holding of a fuse tube member. The top hood and bottom hinge are accepted in opposite ends of the central pins bore and sealed in spaced relationship during manufacturing by the dielectric material added for fabricating the weathersheds.

Fuse cutout insulator

A fuse holder for a fuse cutout includes a molded member including a short fuse tube section and a downwardly extending fin member adapted for securing to a trunnion assembly. An arc quenching liner is disposed in the interior of the tube section and a top casting is connected to the top of the fuse holder and adapted to receive and hold an arc flange of an arc sleeve on a top edge, thereby keeping the arc flange above the top casting. A conductive screw cap seals the assembly. The shorter tube and the provision of the arc flange above the top casting provides superior arc quenching properties.

Fuse holder

A system comprising a portable apparatus and employing a method of admittance versus frequency analysis to detect the existence of a fault in a de-energized electrical line regardless of whether the line contains branches. The portable apparatus comprises a capacitor unit detachably connected to a de-energized line, ground or a neutral conductor, a switch unit detachably connected to a de-energized line, the de-energized line being tested, and an insulated cable connecting the capacitor unit to the switch unit. The switch unit comprises a discharge switch that can be activated by pulling on the hot line tool. The capacitor unit comprises a capacitor which is discharged into the electrical line via the insulated cable and the switch unit when the discharge switch is activated to create a pulse. The capacitor unit comprises circuitry for generating voltage and current samples of pulse response signals and a microprocessor for determining the admittance of the electrical line using Fast Fourier transforms of the current and voltage samples. The admittance of the line is compared with stored data relating to lines having different load impedances and having faults located at various distances from the capacitor unit and detectable at various frequencies to determine the existence of a fault.

Fault detection system including a capacitor for generating a pulse and

In an electrical distribution apparatus a switchgear device has a fixed element disposed within a shielded region of an enclosure of the apparatus, and a movable element supported for movement between a closed position in contact with the fixed element and an open position out of contact with the fixed element. The movable element is disposed at least partially within an access region of the enclosure when in the open position. A panel is supported between the shielded and access regions, and includes a slot through which the movable element passes during movement between the closed and open positions. A barrier member is movable horizontally relative to the panel between a blocking position covering the slot and a non-blocking position exposing the slot. The barrier member prevents inadvertent contact with the fixed element through the slot and prevents movement of the movable element between the open and closed positions when in the blocking position.

Compartment barrier for padmounted switchgear

An electrical switchgear apparatus for use in selectively connecting a primary power line with a tap power line includes a housing in which a switch assembly is disposed. The housing includes a source side wall and a tap side wall generally opposed to the source side wall, and conductors extend through each of the source and tap side walls. A live front terminator is electrically connected with the source side conductor and is adapted to be connected with the primary power line, while a dead front terminator electrically connects with the second insulated conductor and is adapted to be connected with the tap power line. A dead front enclosure surrounds the insulated conductors, the live front terminator, and the dead front terminator. Observation windows in the source side wall and in the dead front enclosure permit visual inspection of the switch assembly from outside of enclosure.

Pad-mounted switchgear with combination live front and dead front

A current interrupting apparatus adapted to be interposed in either a single or multiple phase electrical circuit includes a fuse interposed in each phase of the circuit. A current interrupter is electrically connected in series with each fuse for interrupting the current through the circuit, each current interrupter including a pair of normally closed electrical contacts and structure for opening the pair of contacts in response to a fault current of a magnitude different from the magnitude of current necessary to cause fusing of the fusible element of the fuse. A current interrupter triggering circuit is included in the apparatus for triggering operation of the contact opening structure of all of the current interrupters in response to fusing of the fusible element of any of the fuses to protect the circuit from the effects of single phasing. The current interrupter triggering circuit includes a solenoid electrically connected in parallel with each fuse and operable upon fusing of the fusible element of the fuse to trigger operation of the contact opening structure of all of the current interrupters.

Circuit improvement apparatus having combination current limiting fuse

A motor operator for local or remote shifting of switchgear contacts toward either open or closed positions includes a reversible motor and rotatable drive screw mounted on common support structure for simultaneous pivoting movement as a drive nut translates fore-and-aft along the length of the screw. The drive nut includes an outer body and an inner sleeve which is set into free-wheeling motion whenever the sleeve comes into contact with either of two stops mounted on the screw defining respective end limits of travel for the nut. A drive element normally coupling the nut to an operating shaft of the switchgear is removable to allow the shaft to be manually rotated with a wrench when desired, and removal of the drive element reduces the likelihood that the worker is injured upon unintentional activation of the motor while the operating shaft is turned by hand.

Motor operator for padmount switchgear

An electronic sectionalizer mechanism includes upper and lower contact mounting structure, and a sectionalizer tube carrying a logic circuit is telescopically received within the lower contact mounting structure. Once fault current conditions downstream of the sectionalizer mechanism are detected by the logic circuit, an actuator is fired and the tube drops in a longitudinal, non-lateral motion toward an isolated or open circuit position. In preferred embodiments of the invention, a pin of the actuator shifts along an axis parallel to the longitudinal axis of the tube so that immediate drop-out of the tube is assured. The sectionalizer mechanism requires comparatively little space for operating clearances and this is especially adapted for use on a retrofit basis within the confines of an existing subsurface or pad-mounted switchgear cabinet; additionally, the sectionalizer mechanism may also be installed in existing overhead mounting structure for cutouts.

Electronic sectionalizer and mounting structure for switchgear

An improved, lowcost double-fused vacuum switchgear apparatus designed for underground electrical distribution systems is provided which makes use of a specially configured oil tank-defining wall and insulative protective fuse well sleeves to give enhanced protection to workmen performing unauthorized energized servicing of the unit, while also using a minimum of dielectric oil and separate wall components. The preferred tank includes an oblique sidewall eliminating unnecessary oil space in the tank, while each fuse well is equipped with an insulative sleeve which guides fuse removal and installation and largely prevents short-circuiting even during energized servicing. The fuse assembly preferably includes a current-limiting fuse and a series-coupled expulsion fuse, the latter being oriented in the wells for directing conductive arcing gases downwardly and away from the switchgear components.

Fuse well and housing for pad-mounted, double fused switchgear

A combination dropout assembly adapted for use with protective cutouts in an electrical distribution system comprises a current limiting fuse electrically connected in series with an explusion-type fuse, and mechanically coupled in skewed relation to the latter, whereby the assembly provides reliable full range fault current protection yet is sufficiently compact in length to matingly span the gate between conductive terminals of conventional 15 KV class opengate cutouts found in many existing electrical distributioon systems. Overload and low to medium fault current protection is provided by the expulsion fuse, while high range fault currents are cleared by operation of the current limiting fuse. The oblique arrangement of the fuses relative to one another permits venting from either end of the expulsion fuse without directing potentially detrimental gases toward the current limiting fuse, and further allows the combination of various sizes of current limiting fuses and explusion fuses in the make-up of the dropout assembly such that protection characteristics of the latter may be tailored to preserve coordination of a particular distribution system.

Offset, series connected current limiting fuse and expulsion fuseholder

A lightweight, compact, conductor-mounted open link fault interrupter having mounting means permitting suspension thereof directly from an overhead power line without the need of cumbersome pole-mounting structure. Pinwheeling and flashover problems heretofore encountered during operation of conductor-mounted, closed link interrupters are precluded by virtue of the open link, fusible element employed since through use thereof no net rotational forces are imparted to the interrupter during its operation. The interrupter hereof provides especially advantageous protection when electrically connected in series with a unique high range current limiting fuse capable of safely interrupting high magnitude fault current to insignificant values substantially ahead of the first natural zero point. The resultant combination device is operable to limit the electrical energy dissipated in the conductor carrying the fault current to a desired level in a manner functionally independent of fault current magnitude, and thus provides an appropriate, relatively narrow I.sup.2 t band response over the entire fault range to effectively protect an electrical distribution circuit without impairing desirable coordination of the overall system.

Growing community of inventors

Centralia, MO, United States of America

Lloyd Ronald Beard