Abstract: A highly accurate current sensing transformer, such as an external neutral current transformer (ENCT), accommodates a wide range of loads. The ENCT includes a housing, first and second terminals each having an end portion extending from and external to the housing, a conductor for carrying a current to be measured, and a current sensor having an aperture for receiving the conductor and having a central axis. The conductor joins the first and second terminals to form a current path that passes through the aperture. Increased accuracy is achieved by arranging the conductor such that a portion thereof passing through the aperture forms a substantial angle relative to the central axis, such that the entry angle of the current path via the conductor through the aperture of the current sensor of the ENCT matches an entry angle of a conductor through an aperture of a current sensor in the electronic trip unit to which the ENCT is attached.

Abstract: In a utility monitoring system, a network of intelligent electronic devices (IEDs), including a master IED that receives master clock information from a global positioning system, includes a differential time synchronization (DTS) algorithm for automatically adjusting the corresponding clocks of each of the IEDs to be synchronized with the master clock information. A controller coupled to the network communicates instructions to the IEDs to collect frequency variation data. A known data alignment algorithm determines a point of alignment between two sets of frequency variation data, and the controller determines based on the data alignment algorithm output a time differential representing a time offset between the IED's clock and the master clock information. The time differential is communicated to the target IED, which advances or retards its clock based on the time differential.

Abstract: A monitoring system includes a discoverable wireless device, a proximity monitor, and a monitoring server. The proximity monitor is configured to automatically discover the discoverable wireless device in response to the discoverable wireless device being within a wireless range of the proximity monitor. The monitoring server is communicatively connected to the proximity monitor via a communications network. The monitoring server is configured to i) receive proximity information associated with the discoverable wireless device from the proximity monitor, and ii) transmit an instruction signal based on the received proximity information to an electrical component located remotely from the proximity monitor. The instruction signal causes the electrical component to modify an operating parameter of the electrical component.

Abstract: Electrical load spreading arrangements reduce peak power demand. An enclosure houses an electronic circuit board, which receives at a first input terminal a first thermostat control signal from a thermostat intended to control a first air conditioning unit and at a second input terminal a second thermostat control signal from a thermostat intended to control a second AC unit. A controller on the circuit board is programmed with instructions stored in a memory coupled to the controller causing the controller to monitor the first and second input terminals to determine the timing and duration of the thermostat control signals passed to the output terminals for activating or deactivating the AC units such that overlapping operation of the AC units is reduced particularly during peak demand periods. A similar arrangement may be applied to a broader class of HVAC equipment, including water heaters, for example.

Abstract: A method of automatically identifying whether intelligent electronic devices (IEDs) in a power monitoring system are in multiple electrical grids. A controller sends an instruction to each IED in a predetermined time sequence such that each IED receives the instruction at a different time, commanding each IED to begin logging variation data indicative of frequency variations in a current/voltage signal monitored by the IED and to send the variation data to the controller and an associated cycle count of a point in the current/voltage signal. The controller receives the variation data and associated cycle count and determines a peak correlation using a data alignment algorithm on IED pair combinations. If the IEDs are on the same electrical grid, the peak correlations should occur at cycle count offsets that match the order that the IEDs received the instruction. Any discrepancies in the expected order of peak correlations are flagged, and the corresponding IEDs are determined to be on different grids.

Abstract: A load center is equipped with a neutral phase conductive rail with breaker mounting and retention features providing automatic neutral connection for a plug-on mounted AFI and/or GFI circuit breaker. Breakers may be designed to have specific interfaces to the breaker mounting and retention features of the load center rails. The neutral rail may have two pieces including a breaker undercut positioning rail shorted to a standard neutral rail, or a neutral rail may be designed to have all mounting features integrated therewith. The new panel is compatible with non-AFI and non-GFI breakers.

Abstract: A method of monitoring the electrical power in multiple branch circuits of an AC electrical power distribution system comprises monitoring at least one voltage common to said multiple branch circuits using a main meter unit, monitoring currents of the multiple branch circuits using multiple current cards that receive a plurality of current inputs from current transducers in the multiple branch circuits, sampling the monitored voltage in the main meter unit and the monitored currents in the current cards multiple times in each cycle of the AC power signal, determining the magnitudes and angles of spectral components of the sampled current in the current cards, sending data representing the magnitudes and angles of at least selected spectral components from the current cards to the main meter unit, and storing the voltage samples and the magnitudes and angles of at least the selected spectral components in the main meter unit.

Abstract: A busway system includes a plurality of busbars arranged in a flat stacked configuration. The system further includes at least one uninsulated stab having a base in direct contact with one of the busbars at a first length portion of the busbars. The stab also has a tip extending away from the base and angled at the length of the busbars such that the tip is positioned at least in part at a second length portion of the busbars. The stab is insulated from other stabs via one or more of a MYLAR® sheet and a wall of a plug-in opening base.

Abstract: A multi-pole circuit breaker having the same number of sensors and controllers as poles. One pole is monitored by a first sensor and a first controller, which are disposed on a first circuit board. Another pole is monitored by a second sensor and a second controller, which are disposed on a second circuit board that is cable-connected to the first circuit board. A ground-fault sensor monitors the sum of current flowing through the line conductors and a neutral conductor, and the output of the ground-fault sensor is provided to one or both of the controllers. Each controller is operable to detect arc faults on the respective line that it is monitoring, and at least one is operable to detect ground faults. A push-to-test algorithm is executed in relay fashion, with one controller executing the test before passing the result of the test onto the next controller, which in turns executes the test.

Abstract: Busbars of a busway system are insulated so as to minimize or eliminate air gaps between busbars. In an embodiment, an insulating sheath is provided with corrugations in regions corresponding to busbar bends. The corrugations allow the sheath to follow the busbar bends without the need to cut or interrupt the sheath. Busbars may therefore be fully insulated without the need for further insulating materials (e.g., tape). Good thermal contact between busbars throughout their length is achieved, improving heat dissipation and efficiency.

Abstract: A system and method are disclosed for the automated discovery of devices on a network, such as a TCP/IP network using Dynamic Host Configuration Protocol (“DHCP”) and Domain Name System (“DNS”) servers. Devices on the network may be discovered, identified, and tracked by a monitoring server. Communications with the monitoring server may include identification information for each device. The identification information may be stored in DHCP option fields, transmitted with DHCP messages, and used to identify whether the device is new to the network.

Abstract: A unitary die-cast cap for a downlight can includes a base section and a plurality of heat-sink fins. The base section is a plate that includes an interior base-surface, an exterior base-surface, and an exterior wall-surface. The exterior base-surface, which is an opposite surface of the interior base-surface, forms an exterior top-surface of a downlight tubular can. The exterior wall-surface is configured to be positioned in direct attachment to an interior wall-surface of the downlight can. The plurality of heat-sink fins extend from the interior base-surface and form a substantially cylindrical exterior heat-sink wall touching or in close proximity to the interior wall-surface of the downlight can.

Abstract: Aspects of the invention support direct communication between a low-level device and a programmable controller over an automation bus in an industrial automation system for controlling and monitoring an industrial process. A leaf node device may include a low-level device. The leaf node device communicates directly with the programmable controller at the network layer, e.g., Internet Protocol (IP) based on an IP address contained in a signal so that the programmable controller may control the low-level device or receive status information about the low-level device. The industrial automation system may support a plurality of leaf node devices, which may be associated with different automation buses having different communication media. Signals between the programmable controller and the leaf node device may be directed with or without a switching element.

Abstract: A method and system to calibrate a motor circuit protection device is disclosed. An example method calibrates a signal chain of a circuit breaker. The signal chain includes a current transformer, a burden resistor, a stored energy circuit and a controller. The circuit breaker includes a memory coupled to the controller. A calibration instruction routine is written in a first location of the memory. A test current is injected in the circuit breaker signal chain. The test current peak of the test current in the circuit breaker signal chain is measured. Data indicative of the test current peak is stored in a second location of the memory. The test current peak data is read from the second location of the memory. The test current peak data is compared with nominal current data related to the signal chain remotely from the circuit breaker. A calibration factor is determined based on the comparison.

Abstract: A voltage isolation circuit. The input voltage Vin is connected to a primary winding of a transformer T1 through a current limiting resistor R1. R1 is preferably sized such that the current flow in the primary at nominal input voltage is approximately 1 milliamp. Transformer T1 is wound as a current transformer with a fixed ratio between the primary and secondary windings. Thus, when 1 mA flows in the primary winding, 1 mA will also flow in the secondary winding. An inverting operational amplifier will continuously attempt to drive its inverting input to a zero potential through resistor R2. The voltage at Vout produced by the op-amp is a faithful replica of the voltage at Vin, but scaled according to the values selected for R1 and R2.

Abstract: A method of storing data in a utility monitoring system includes monitoring a characteristic of a utility system in an intelligent electronic device (IED) to produce monitored characteristic values that are buffered in the IED. The IED is communicatively coupled to a server via a network. The monitored characteristic values are indicative of the characteristic. The method further includes storing a first monitored characteristic value of the buffered monitored characteristic values periodically at a first logging interval in a memory of the IED. The method further includes storing a second monitored characteristic value of the buffered monitored characteristic values periodically at a second logging interval in the memory of the IED in response to satisfying a criterion. The second logging interval is distinct from the first logging interval.

Abstract: An add-on module adapted to be attached to the basic mechanical structure of a multi-pole circuit breaker includes multiple extended terminal plates each of which is adapted to replace one of the input and output terminals for one of the poles, multiple electromechanical transducers each of which is coupled to one of the extended terminal plates for producing a mechanical movement in response to a predetermined magnitude of electrical current in the extended terminal plate to which that transducer is coupled, a mechanical actuator coupled to the electromechanical transducers and to the breaker contacts for operating a trip mechanism in response to a predetermined mechanical movement of any of the transducers, and a mechanical reset arm coupling the reset mechanism to the mechanical actuator for resetting the actuator in response to the resetting of the host circuit breaker.

Abstract: A method for automatically updating an existing firmware file stored in a memory of an intelligent electronic device (IED) communicatively coupled to a network in a monitoring system. The IED downloads from a remote server to the IED an update file that includes a version of a firmware file and a filename of the firmware file. The IED determines whether the firmware version specified in the update file is updated compared to a version of the existing firmware file. If the firmware version in the update file is greater than the existing version, the IED communicates to the remote server an instruction to download to the IED the updated firmware file specified in the update file. The IED receives from the remote server the updated firmware file. If a criterion is satisfied, the IED automatically updates the firmware file stored in its memory with the updated firmware file.

Abstract: A bimetal in a circuit breaker can deflect in a first direction or a second direction depending upon conditions. If the bimetal deflects in the second direction it can increase the force necessary to operate a trip mechanism of the circuit breaker. A yoke stop helps to control bimetal deflection forces and thus, the amount of force necessary to operate the trip mechanism. This allows better control, size, and selection of operating parts for the circuit breaker.

Abstract: A method of managing a power monitoring and control informational system that encompasses multiple intelligent electronic devices (IEDs) of varying types comprises creating different device types, including tags associated with each of the device types; creating at least one profile for each of the device types; and generating a user interface display that enables a user to create a new profile, the display including options to create a new profile or to create a profile by modifying a copy of data representing an existing profile.