135 results about "Ground and neutral" patented technology

The invention provides a method and a device for communicating a signal over a power line. One embodiment may comprise a length of power cable that comprises a center conductor substantially surrounded by an insulator. A concentric conductor is disposed external to the insulator over a first portion of the cable. A coupling conductor may be disposed concentrically around a second portion of the cable external to said insulator and having a first end and a second end. The concentric conductor is absent in a manner to form a gap between the concentric conductor and the first end of said coupling conductor. A transceiver cable is coupled to the first end of said coupling conductor and a common mode choke may be disposed substantially around the entire circumference of a portion of said coupling conductor. Finally, the second end of the coupling conductor may be coupled to ground through a convenient neutral conductor.

The present invention is directed to an electrical device configured to be disposed in an electrical distribution system between a source of electrical power and an electrical load. The electrical distribution system includes at least one line hot conductor, a line neutral conductor, and a line ground conductor. The line neutral conductor and the line ground conductor are connected to earth ground at a termination point in the electrical distribution system. The electrical load includes at least one load hot conductor, a load neutral conductor, and a load ground conductor. The device comprises a power supply coupled to the power input mechanism. The power supply comprises at least one DC voltage output terminal and a reference terminal coupled to the line ground termination element. A voltage parameter detection circuit is configured to take a first voltage reading from a first termination element of the plurality of line termination elements and a second voltage reading from a second termination element of the plurality of line termination elements to derive at least one voltage parameter therefrom. The first voltage reading and the second voltage reading are referenced to the reference terminal. The circuit interrupter is driven into the tripped state if the at least one voltage parameter does not meet a predetermined condition, the voltage parameter detection circuit being operational when the reference terminal is not at an earth ground potential.

A circuit interrupting device having a reverse wiring protection function is disclosed. The circuit interrupting device includes a housing having a cover and a base, a mounting plate, and an electrical component mounting member, a pair of input hot and neutral conductors and a pair of output hot and neutral conductors, a differential transformer for detecting a leakage current, a disconnecting mechanism for connecting and disconnecting the output conductors to and from input conductors, and a mechanism for preventing reverse wiring, which includes a coil connected to the input hot and neutral conductors and a moveable piece that moves when the coil is energized. The input and output conductors are electrically connected only when the coil is energized by correctly connecting the power wires to the input conductors of the device. This device thus provides both leakage current protection and reverse wiring protection that protects against incorrect wiring during installation.

An overvoltage protection device for protection of low voltage electrical installations, has a device base part with terminals for phase conductors and ground or neutral conductors and at least one overvoltage protection element, with at least one arrester which is located in a housing. The base part of the device has at least one telecommunications contact which has a switch for remote indication of the state of at least one overvoltage protection element, the base part of the device having plug contacts which are connected to the terminals, and the overvoltage protection element having corresponding connector contacts so that the overvoltage protection element can be plugged onto the base part of the device. The overvoltage protection device is improved by the overvoltage protection element having an optical status display and the optical status display and the switch of the telecommunications contact being actuated via a common mechanical actuating system.

The coupler of the present invention couples data signals, such as broadband RF signals, to and from a power line. The coupler of one embodiment that is for use with overhead power lines includes a length of URD MV cable with the neutral conductor removed. Each end of the URD cable is communicatively coupled to the MV power line conductor a predetermined distance from other. The distance between the two connections points on the MV may be related to the wavelength of a carrier frequency used to communicate the data signals. The URD cable may also form part of a transformer to permit the passage of data signals while preventing the flow of the high voltage power signals through the coupler. The neutral semi-conductive jacket of the URD cable may be coupled to ground via a low frequency conductive path.

An arc fault circuit interrupter includes separable contacts, a neutral conductor, an operating mechanism structured to open and close the separable contacts, at least one current sensor structured to sense current flowing through the separable contacts and output a sensed current value; and a processor. The processor includes a first routine structured to provide parallel arc fault detection, a second routine structured to provide series arc fault detection, and a third routine structured to enable the first routine and disable the second routine for a predetermined time when the sensed current value is greater than a predetermined value and to enable the second routine and disable the first routine for the predetermined time when the sensed current value is less than the predetermined value.

The present invention relates to current measurement apparatus. The current measurement apparatus comprises first and second measurement devices with each of the first and second measurement devices being operative to measure current in a respective one of a live conductor and a neutral conductor substantially simultaneously. The current measurement apparatus is operative to make plural different determinations in dependence on the substantially simultaneous current measurements.