The invention relates to a method and a device for identifying and locating cyclic momentary insulation faults in an ungrounded power supply system, the method comprising the steps: detecting a fault current caused by the momentary insulation fault as a differential current in the branch circuit to be monitored and displaying the temporal progression of the differential current via a differential current signal by means of a differential current sensor; providing a processing signal which temporally describes a process sequence of a process taking place in the consumer; correlating the differential current signal with the processing signal in a computing unit in order to yield a correlation signal as a measure for a temporal match between the differential current signal and the processing signal; signaling the momentary insulation fault via the computing unit by means of a signaling signal if the correlation signal shows the temporal match. The device according to the invention has a differential current sensor and a computing unit so that it can implement the method according to the invention.

The invention relates to an optical insulation monitoring device for power cables, having at least one optical waveguide for transmitting an optical signal integrated into a polymer film. The polymer film is arranged in such a way that the radially outer surface of the cable is surrounded by the polymer film in at least one longitudinal portion of the cable. At least some of the optical waveguides can be designed as multimode waveguides. The optical waveguides may be integrated in a plurality of layers in the polymer film, the optical waveguides of a first layer being arranged in staggered fashion with respect to the optical waveguides of a second layer arranged above or below the first layer. In this way, at least a section of the polymer film in the film plane is completely covered by the optical waveguides without any unwanted crosstalk between adjacent optical waveguides resulting.

Data center mechanical infrastructure is incrementally deployed and commissioned to support incremental changes in computing capacity in a data center while mitigating interaction between infrastructure being commissioned and installed computer systems. Incremental mechanical infrastructure commissioning can be concurrent with incremental electrical infrastructure commissioning and includes operating mechanical infrastructure to remove heat generated as a result of operating electrical infrastructure to support simulated electrical loads as part of electrical infrastructure commissioning. Incremental mechanical infrastructure deployment can be based on the power support capacity provided by incrementally deployed electrical infrastructure. Incremental infrastructure deployment can include partitioning a space in which incremental mechanical infrastructure is configured to provide cooling, so that heat generation and removal in the space, based on commissioning the incremental mechanical infrastructure, is isolated electrical and cooling support provided to electrical loads located in a remainder of the data center.

A power supply system includes first and second power supply lines to respectively connect positive and negative electrode terminals of a load with a main power supply. First and second voltage detection lines are respectively connected to the first and second power supply lines via first and second resistances. First and second inspection power supplies respectively supply power and provide potential differences to the first and second voltage detection lines from the first and second power supply lines. Occurrence of a short circuit in one of the first and second voltage detection lines is recognized when corresponding one of the first and second inspection power supplies supplies power and a difference between a preset voltage and a voltage caused between the first and second voltage detection lines is a threshold value or more.

A power supply system includes first and second power supply lines to respectively connect positive and negative electrode terminals of a load with a main power supply. First and second voltage detection lines are respectively connected to the first and second power supply lines via first and second resistances. First and second inspection power supplies respectively supply power and provide potential differences to the first and second voltage detection lines from the first and second power supply lines. Occurrence of a short circuit in one of the first and second voltage detection lines is recognized when corresponding one of the first and second inspection power supplies supplies power and a difference between a preset voltage and a voltage caused between the first and second voltage detection lines is a threshold value or more.

An electrical wiring device including: a plurality of line terminals comprising a line-side phase terminal and a line-side neutral terminal; a plurality of load terminals comprising a load-side phase terminal and a load-side neutral terminal; a line conductor electrically coupling the line-side phase terminal to the load-side phase terminal; a neutral conductor electrically coupling the line-side neutral terminal to the load-side neutral terminal; and a controller configured to trigger a trip mechanism to electrically decouple the at least one of the plurality of line terminals from at least one of the plurality of load terminals based, at least in part, on comparing a magnitude of the current differential to a threshold, wherein the threshold is a function of the frequency of the current differential.

An electrical wiring device including: a plurality of line terminals comprising a line-side phase terminal and a line-side neutral terminal; a plurality of load terminals comprising a load-side phase terminal and a load-side neutral terminal; a line conductor electrically coupling the line-side phase terminal to the load-side phase terminal; a neutral conductor electrically coupling the line-side neutral terminal to the load-side neutral terminal; and a controller configured to trigger a trip mechanism to electrically decouple the at least one of the plurality of line terminals from at least one of the plurality of load terminals based, at least in part, on comparing a magnitude of the current differential to a threshold, wherein the threshold is a function of the frequency of the current differential.

Systems and methods to estimate trapped charge for a controlled automatic reclose are described herein. For example, an intelligent electronic device (IED) may calculate an analog amount of trapped charge of each phase of a power line based on voltage measurements of the power line. The IED may close a switching device of each phase at a time corresponding to a point-on-wave associated with the analog amount of trapped charge of the respective phase.

Systems and methods to estimate trapped charge for a controlled automatic reclose are described herein. For example, an intelligent electronic device (IED) may calculate an analog amount of trapped charge of each phase of a power line based on voltage measurements of the power line. The IED may close a switching device of each phase at a time corresponding to a point-on-wave associated with the analog amount of trapped charge of the respective phase.

A method and apparatus for electrical line testing. The method and apparatus provides audio, visual and/or electronic information to indicate electricity is flowing or not flowing through an electrical circuit controlled by a remote circuit breaker. The method and system help identify which electrical sockets are controlled by which remote circuit breakers. The method and apparatus is used over short distances in a residential home or over long distances in a commercial building such as a warehouse or factory. The method and apparatus is also used via a cloud communications network and with smart speakers. The method and apparatus is used with or without an external network devices such as a smartphone, electronic tablet, wearable device, etc.