Schneider Electric Usa, Inc.

Square D Company

Julius Michael Liptak

John Kenneth Mackenzie, Iv

Kevin M Jefferies

Benjamin W Edwards

Matthew L White

Richard Karl Weiler

Alan Freeman

Mark Kocher

Gary W Scott

Scott Robert Brown

George H Studtmann

Alexander Filippenko

Konstantin Filippenko

James V Fixemer

Barry Noel Rodgers

Donald H Ward

Richard W Roof

Michael J Gerlach

John J Shea

F Carl Joyner, Jr

Kenneth S Berton

Gary Myron Kuzkin

Richard Gerhard Spangenberg

Andy Allen Haun

Robert Joseph Dwulet

Iv John Kenneth Mackenzie

Methods and systems for suppressing arc formation in branch breakers provide a load center that can monitor a branch breaker for indications of arc formation. The load center may include a main breaker that can immediately cut current to the upon receiving an indication of an arc forming in the branch breaker. The indication may be provided by a sensor circuit that sends a trigger signal to the main breaker when arc formation is detected within the branch breaker. The main breaker checks that the trigger signal indicates arc formation, then cuts current to suppress the arc. The main breaker then waits a short period for the branch breaker to clear before restoring current. The wait period is sufficiently short such that devices receiving power from the load center are not adversely affected. To improve cutoff and restoration response times, the main breaker employs a solid-state trip switch.

Arc suppression in circuit protective devices

A system and method is provided to monitor wear on a power factor correction capacitor in a motor system. The system and method obtains a baseline inductance angle, reactive power or power factor corresponding to a baseline power factor correction by the capacitor in the circuit; monitors a current supplied to the motor at a location upstream of the capacitor; monitors a voltage supplied to the motor, and determines a present inductance angle, reactive power or power factor based on the monitored current and voltage. The present inductance angle, reactive power or power factor corresponds to a present power factor correction by the capacitor. The system and method can then determine when the power factor correction of the capacitor has degraded to an unsatisfactory level based on a change in the inductance angle, reactive power or power factor from the baseline values, and take appropriate action.

Power factor correction capacitor wear detection

A method of performing temperature-based diagnostics for motor starters within a physical grouping of motor starters is performed by determining a presently expected temperature operating range for each starter based on measuring operating temperatures of the starters; measuring their current draws, and evaluating the temperature and load draw data in light of compensation values assigned for the known power ratings of the starter and the starter's physical location within the grouping. With the presently expected temperature operating range of the starter determined, and the periodic monitoring of starter temperatures, when an individual starter's temperature exceeds its expected range, a diagnostic warning will be issued for that starter and/or for the control panel itself as a guide for preventative maintenance. Alternately, the warning may be issued for an unexpected temperature rise for a given rise in current draw, or for values exceeding an expected rate of temperature change.

Temperature-based diagnostics method for a starter island

Nuisance tripping is reduced in a power protection and distribution system including an upstream circuit breaker, a power distribution bus, and one or more downstream circuit breakers. A signal indicative of a current or pending downstream circuit breaker tripping action, such as a Zone Selective Interlocking (ZSI) signal, normally used to delay tripping of the upstream breaker, is used to suppress an optical flash detection system from tripping the upstream breaker in response to an optical flash resulting from the tripping of the downstream breaker. In this way, nuisance tripping of the upstream breaker is avoided when the downstream breaker trips (and the ZSI function is preserved).

Zone selective interlocking for optical flash detection suppression

In a power protection and distribution assembly a trip system monitors electrical current and sends a current status signal to an arc flash protection system indicating whether current characteristic of an arc event is detected. The arc flash protection system evaluates this current status signal along with a light status signal indicating whether light characteristic of an arc event has been detected. Based on this evaluation, the arc flash protection system sends a control signal to the trip system for controlling the trip system to trip a breaker. The systems each include a full-duplex signaling module for sending the signals between the systems over a pair of conductors. Each signaling module sends one of the signals by modulating the magnitude of a current through or a voltage across the conductors, and receives the other signal by demodulating the magnitude of the current through or the voltage across the conductors, as distinctively modulated by the other signaling module.

Full-duplex signaling for arc event protection

In an electrical distribution system an arc management system has a transducer mounted in proximity to the circuit breaker for detecting and signaling a secondary effect of an overcurrent event within the case of the circuit breaker. The transducer provides an additional input to an arc fault detection system using other detectors and thus helps to control nuisance activations of the arc extinguishing mechanism. The system is particularly suited for circuit breakers without electronics, or the like, allowing for retrofit of existing systems. The system may monitor and act upon the excessive duration of the secondary effects.

Circuit breaker signaling system for control of an arc fault detection system

An intelligent power management system that includes a circuit breaker containing a PLC module that spans open contacts of the circuit breaker to provide a communication path for PLC messages between communication paths on each of the line and load sides of the circuit when the contacts are open. The contacts are motorized to permit remote operation through PLC messaging. Coupled to the PLC module is a controller, which controls the opening and closing of the motorized contacts under user control or via an adaptive load management algorithm that reduces peak power consumption and adapts a set of loads to changed power supply conditions. The controller can also dynamically alter operational current and fault threshold levels on a real-time basis based upon circuit requirements or environmental conditions. The algorithm runs a state machine and also manages loads in a limited power source environment such as when loads are powered by a generator.

Method of facilitating communications across open circuit breaker contacts

A power inverter comprises a push-pull inverter circuit that includes a transformer having a primary winding coupled to a DC bus and a secondary winding coupled to an AC bus, main power switches coupling each end of the primary winding to a DC return, and one or more supplemental power switches coupling at least one end of the primary winding to a snubber bus. The supplemental switch at a given end of the primary winding forms a buck-mode converter in combination with the primary winding and the associated free-wheeling diode at that end of the primary winding, and can be controlled by a switching controller to effect energy transfer between the snubber bus and DC bus. The switching controller can be configured to control power flow between the DC, AC, and snubber buses by controlling the common-mode and differential-mode voltages of the primary winding via main/supplemental power switch control.

Push-pull inverter with snubber energy recovery

A method for protecting a printed wiring board (PWB) and the electrical components mounted on the PWB from high temperature, fire, plasma and debris resulting from a catastrophic failure of an at-risk electronic component located on the PWB or in close proximity to the PWB. This protection is provided by a layer of inorganic refractory material applied to a surface of the PWB adjacent the at-risk electrical component. The refractory material is preferably applied to the PWB surface as a pourable liquid. The refractor material must have sufficient viscosity such as to easily flow in and around electronic components located on the PWB and be self-leveling before curing, so as to produce a uniform thickness. The refractory material should also have a small shrinkage factor when cured such that no gaps are created between the PWB and the enclosure and around the electrical terminals of the at-risk components.

Protected and printed wiring board and method of making same

A protective containment apparatus for preventing damage to expensive components of an assembly due to the failure of an electronic component in a nearby potted circuit which is known to fail catastrophically. The containment apparatus can employ a resilient material,placed around the at-risk electronic component,prior to potting the circuit. The resilient material,absorbs the expanding gases and fragmented parts of the at-risk component,which are expelled during the catastrophic failure. The cushioning effect of the resilient material,prevents the fragments and parts of the potting material from becoming projectiles that can damage any nearby components of the assembly. The containment apparatus can also employ a restrictive material,placed around the at-risk component,prior to potting the circuit. The restrictive material,prevents any expelled fragments of the at-risk component,and expanding gases from causing the potting material to fracture and become projectiles which can damage nearby components of the assembly. A combination of the resilient material,and the restrictive material,can also be employed and is most effective in preventing damage to nearby component of the assembly.

Protective containment apparatus for potted electronic circuits

A solid state circuit interruption arrangement in a distributed power network provides fast and reliable circuit interruption. A common power source provides power to a plurality of loads via respective current paths. A main circuit breaker and a plurality of solid state circuit breakers are arranged to interrupt the current paths in response to command signals sent from a central controller. Current sensors and voltage sensors are coupled to the current paths for monitoring purposes. An automatic controller responds to any of the current sensors detecting a fault condition by automatically generating a command signal, which forces the associated solid state breaker to interrupt the associated current path. Thereafter, the controller automatically generates a signal to the main circuit breaker to interrupt the power provided from the common power source in the event that the associated current path is not interrupted by the solid state breaker. Alternatively, or in addition, the main interruption device may interrupt the current path when its own internal sensing mechanism detects a magnitude of current that is beyond a predetermined level. Also, the controller automatically generates a signal to the main breaker to interrupt the power provided from the common power source in the event that any of the branch breakers fails in the 'off' or interrupted, condition. Other features include a finned housing structure which provides cooling means for the breaker system without the need for cooling fans.

Fail-resistant solid state interruption system

An adjustable speed pumping system includes a plurality of pumps respectively driven by variable speed A.C. motors each having a power recovery circuit. Each power recovery circuit includes a series connected rectifier bridge, an inductive reactor and an inverter coupled to the secondary winding of the motor which has an A.C. source connected to the primary winding. A fault clearing mechanism is included in each circuit and includes solid state switches in the bridge actuated by a current level sensor coupled to the inverter output. The power recovery circuit also includes current foldback circuitry and secondary gating circuitry coupled to thyristors in the inverter. The power recovery circuits can be connected in parallel with a single motor and the system includes circuitry for sensing the highest amplitude current in the parallel circuits and controlling all circuits with this current. Each pump has a valve associated with the outlet and circuitry associated therewith to operate the pump at a low forward speed upon receipt of a stop command until the valve is closed to prevent significant reverse flow through the pump.

Automatic fault protection system for power recovery control

A circuit for sensing the motor stator voltage on any one or more phases of an AC electrical drive system. In a three phase system, all three phases of the motor terminal voltage are applied to a modified six-pulse rectifier bridge which in turn feeds a loading resistor. A resistor is added in series with each diode pair of the six-pulse rectifier bridge in order to provide any degree of attenuation of the peak voltage developed across the load resistor by simply varying the resistance values of these series input resistors and the load resistor. The resulting DC voltage generated across the load resistor is then fed into a differential amplifier (stage) where the voltage is attenuated and impedance isolated from the source to provide a DC output which is proportional to the average applied AC motor stator voltage.

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Knightdale, NC, United States of America

Julius Michael Liptak