Abstract: The present invention provides improved and more efficient methods and apparatus for maintaining and/or adjusting over-travel gaps and contact wipe portions in operating rod assemblies of circuit interrupters.

Abstract: Dynamic thresholds statistically derived are used to define normal conditions at a specific site in an electric power distribution system. High and low and/or caution and alarm thresholds for various parameters are generated as multiples of the standard deviation of the long-term average of measured values calculated from samples gathered over repetitive intervals, such as ten minutes. Weekly averages are used until sufficient data has been gathered to maintain a running one year average.

Abstract: The movable conductors of a three phase isolation switch are incorporated into the electrically insulative molded shaft, thereby mechanically supporting them and isolating them from the metal axle of the shaft. Movable contacts on the ends of each movable conductor are angularly spaced by ? degrees, where ? is less than 180° and is 90° in the exemplary embodiment. A common fixed load contact is located angularly between, and spaced ? degrees from, both the fixed line and ground contacts so that the shaft is rotated only ? degrees between a first, closed position, in which the movable conductors connect the fixed load contact for each phase to the corresponding fixed line contact, and a second, grounded position, where the fixed load contact of each phase is connected by the movable conductor to the corresponding fixed ground contact.

Abstract: A control circuit operates a dual directional DC motor from an AC power source. A controller has first and second position indication inputs adapted to receive respective first and second position indications. The controller also has first and second direction outputs, which respectively energize one of two first relay coils having contacts outputting respective AC voltages responsive to the direction outputs. A full wave bridge rectifier receives the AC voltage and responsively outputs a DC voltage, which energizes a second relay coil. A contact thereof directs that voltage to two sets of first relay contacts, which are also responsive to the direction outputs, and which respectively provide a positive or negative DC voltage to the motor. Another second relay coil contact provides a braking action to the motor responsive to removal of the DC voltage from the rectifier output following removal of the AC voltage to the rectifier.

Abstract: A cover assembly controls access to the interior of an electrical enclosure. The electrical enclosure includes a housing having a panel and a plurality of walls extending from the panel to define an opening. The cover assembly includes a door-in-door assembly with first and second hinged doors and a concealed mounting mechanism. The concealed mounting mechanism secures the door-in-door assembly to the housing without requiring a separate securing mechanism. The first hinged door pivots open to access the housing without requiring the first door to be entirely removed. The second hinged door is smaller and thus provides convenient access through a cut-out portion of the larger first door. Access may be further controlled via a locking mechanism for locking the second door in a closed position within the first door.

Abstract: A composite power quality indication generated from user weighted statistical contributions of selected system parameters provides an overall indication of power quality in an electric power distribution system. The user defined weightings are maintained over time by continually updating sensitivities that normalize the component contributions to the composite power quality indication. The current composite power quality indication is displayed in relation to its long-term mean and to dynamic thresholds determined as multiples of the standard deviation of the long-term mean.

Abstract: A circuit interrupter arc chute includes first and second support portions, an exit portion supported by the support portions, and a plurality of arc plates supported by the support portions. The exit portion has one or more vent openings. The arc plates have a first edge offset from the exit portion and an opposite second edge distal from the exit portion. A plurality of insulating dividing members are disposed between the arc plates. The members have a first edge proximate the exit portion and an opposite second edge distal from the exit portion. The second edge of the members extends beyond the arc plate first edges and toward the arc plate second edges. The first edge of the dividing members extends beyond the arc plate first edge and away from the arc plate second edge.

Abstract: A moving contact assembly for a high-current interruption electric power switching apparatus has an inner carrier for the contact fingers that is rigidly held in a withstand position in an outer carrier by a spring biased cam follower pin engaging a cam profile on the inner carrier and configured to positively seat an inner carrier stop against an outer carrier stop on the outer carrier and to rapidly drive the inner carrier to a blow open position in response to a fault. The cam profile has an extended width divided between spaced apart cam profile sections to absorb the high closing and withstand forces. An abutment on the outer carrier resists bowing of the cam follower pin between the cam profile sections. Complementary convex and concave partial cylindrical surfaces on the inner carrier and a gas shield on the moving assembly carrier body maintain an arc gas seal during blow open.

Abstract: An apparatus detects arcing faults at a first wavelength. A light source provides modulated light at a second different wavelength and a first frequency. An optical fiber receives the modulated light and gathers ambient light at both wavelengths. A splitter receives and splits the received light into first and second beams. A first filter extracts from the first beam a first filtered beam including the first wavelength. A first photodetector generates a first electrical signal from the first filtered beam. A second filter extracts from the second beam a second filtered beam excluding the first wavelength. A second photodetector generates a second electrical signal from the second filtered beam. A low pass filter extracts from the second electrical signal a third electrical signal representative of light at the second wavelength excluding the modulated light. A comparator generates an arcing signal when the first electrical signal exceeds the third electrical signal.

Abstract: The auxiliary switch includes a non-contact sensor, such as a Hall effect device, that is switched by the condition of a magnetic field. The magnetic field condition is effected by a movable contact indicator that moves between open and closed positions with the separable contacts of the electric power apparatus. A magnet may be attached to the movable contact indicator, or the movable contact indicator can be magnetized to form the magnet. Alternatively, the moving contact indicator can intercept or not intercept a magnetic field produced by a fixed magnet spaced from the sensor. The Hall effect device may be mounted on the outside of the nonmagnetically permeable housing of the electric power apparatus, or inside if there is sufficient room. In either case, no mechanical coupling is required for the sensor.

Abstract: The difference in voltages measured upstream and downstream of a pressure junction in a power distribution system produced by the energizing power is divided by the measured current to calculate a value that is a function of the impedance of the pressure junction, which is monitored for deterioration. To eliminate noise resulting from dividing a small number by a large number and transients in the power distribution system, the impedance is calculated from the squares of the voltage differences and currents for a large number of samples, and the change between successive calculations is limited to produce a stable median value.

Abstract: A circuit breaker with a thermal/magnetic trip device incorporates a monitor that senses the temperature of the bimetal and the amplitude of the load current to distinguish between a thermal and a magnetic trip. If the temperature of the bimetal is above a selected value when the circuit breaker trips, a “THERMAL” trip light emitting diode (LED) is energized, while a high load current at the time of a trip lights a “MAG” trip LED. The monitor also energizes an “ARC” LED in response to an arc fault signal from an AFCI at the time of trip, or a “GRD” LED in response to a ground fault trip. If a trip sensor, which monitors load voltage does not detect opening of the circuit breaker contacts when an arc fault or ground fault signal is generated, the corresponding LED is flashed to indicate the failure to trip. The monitor also has a “SURGE” LED to indicate a voltage surge in the protected distribution system as detected by a surge detector built into the circuit breaker.

Abstract: A U-shaped accessory actuator clip that snaps onto the crossbar of a multipole circuit breaker is integrally molded of a compliant material with a flexible finger that actuates/deactuates an accessory, such as an auxiliary switch, as the contacts of the breaker close and open.

Abstract: A mounting bracket for the motor within a motor operator for a circuit breaker may be secured within the motor operator's housing a first orientation, thereby permitting it to support a first type of motor. Placing the mounting bracket within the housing in a second orientation permits the mounting bracket to accommodate a second type of motor.

Abstract: A racking device performs a circuit breaker racking operation. The racking device includes a base with wheels and a brake to facilitate moving the racking device and positioning it with respect to a switchgear cabinet. An elongated tubular member extends substantially vertically from the base. A self-contained counter-balanced power module includes an enclosure having a pair of opposing openings for receiving the elongated tubular member, and a counterweight system for counter-balancing the power module. An actuator including a motor, a ball spline and a torque member moves a linkage assembly having an end effector with a negator spring that positively engages the circuit breaker. A switch module actuates the actuator from a remote location in order to move the linkage assembly and thus the circuit breaker to perform the racking operation from the remote location. Complicated field programming of the power module is not required.

Abstract: A clamp-jaw contact assembly is for a meter socket including a socket block having plurality of meter socket receptacles. The clamp-jaw contact assembly includes a stationary contact structured to engage a corresponding one of the meter socket receptacles, a moveable contact pivotally coupled to the stationary contact by a pivot member, such as a rivet, and a clamping element which is coupled to the stationary contact and includes an integral jaw spring. The integral jaw spring biases the moveable contact toward the stationary contact in order to secure a meter bayonet therebetween. The moveable contact also has a closed position in which it resists insertion of the meter bayonet between the moveable contact and the stationary contact.

Abstract: An electrical switching apparatus interface assembly provides remote actuation of the operating handle of a circuit breaker. The interface assembly includes the circuit breaker, a second switching apparatus, such as an actuating handle disposed in a remote location from the circuit breaker, a connector and an operating handle attachment including a handle-engaging segment for securely engaging the circuit breaker operating handle and an interfacing segment for receiving the connector. The actuating handle is operable between ON and OFF positions corresponding to ON and OFF positions, respectively, of the circuit breaker operating handle. The connector interfaces or links the circuit breaker to the actuating handle. In this manner, when the actuating handle is moved from the ON or OFF position, the connector moves the circuit breaker operating handle in a likewise manner.

Abstract: A door interlock assembly is for a draw-out circuit breaker assembly. A draw-out circuit breaker is housed within an enclosure including a door and includes a poleshaft operable between first and second positions corresponding to separable contacts being opened and closed, respectively. The door interlock assembly includes a pivot member coupled to the poleshaft and a door latch interconnected to the pivot member by a linkage, such as a threaded drive rod. The door latch pivots such that a first end thereof engages and locks the door of the enclosure when the poleshaft moves to the second position. An optional mechanical sensor assembly adapted to trip the circuit breaker when the door is positioned in any position other than closed, is also disclosed.

Abstract: A method controls and monitors a parallel array of a plurality of rectifier bridges each of which is adapted to convert a plurality of alternating current voltages of a plurality of alternating current phases to a voltage. The bridges include a plurality of segments each of which has an element. Each of the elements of one bridge is electrically interconnected in parallel with at least one corresponding element of at least another one of the bridges. A plurality of control signals are output to repetitively fire the elements. Conduction or non-conduction of the elements is sensed. The method determines, for the elements of the bridges, if any of the elements of one bridge and all of the at least one corresponding element of at least another one of the bridges, which are electrically interconnected in parallel, have the sensed non-conduction. An alarm signal is output responsive to the sensed non-conduction.