Square D Company

Schneider Electric Usa, Inc.

Henry J Zylstra

James P McGinnis

Harley W Jansen

Robert F Dvorak

Gary Allan Volesky

Ronald J Etscheidt

Ronald D Borrett

Steven J Flock

Andy A Haun

James W Dickens

David Joseph Dunne

Darrell P Ophaug

Oliver Glennon

Steven M Meehleder

Donald R Venzke

James Arthur Heise

Robert E Dietz

Kenneth W Erickson

Charles D Bettis

Jesil Surendra Pujara

Robert W Dunham

Jesil Pujara

A module for a high voltage electronic circuit breaker that includes a power supply and related circuitry for suppressing high voltage transients. The power supply receives a range of voltages, such as up to 600V, and is powered from the line current instead of through a transformer, exposing the module electronics to potential voltage transients. A large capacitor is connected to the high voltage input for absorbing the energy of a voltage transient. Transient voltage suppressors are connected in parallel to the capacitor to absorb any further energy in the transient not absorbed by the capacitor. Inductors are series-connected with the high voltage input to present an impedance and inductance to the voltage transient, reducing the transient before it reaches the power supply. Inductors in the trip coil and the indicator coils also present an impedance and inductance to the transient, further enhancing protection against transients. Fuses connected in line with the high voltage input protect the module electronics against short circuits.

Earth leakage detection module with robust transient suppression

A portable, remote racking device that is controlled by a remote control. The remote racking device includes a drive that fits into a corresponding crank access hole formed in a front panel of a cradle housing a circuit breaker installed into a switchgear. The drive turns a mechanism inside the cradle that causes the circuit breaker to be racked into or out of the switchgear. The remote racking device includes an actuator pin that abuts a corresponding button arm protruding through the front panel. The remote control includes a control for depressing the button arm and another control for causing a motor to rotate the drive. The actuator pin detects when the button arm pops out of the panel, and a circuit in the remote racking device briefly reverses the motor to bring it and the circuit breaker to a sudden stop, preventing the mechanical linkages of the mechanism from locking-up or becoming damaged and avoiding over-torquing the motor.

Portable remote racking device for a circuit breaker

A current sensor assembly used for detecting ground faults, which includes an enclosure surrounding the current sensor for focusing the magnetic flux produced by conductors passing through the current sensor assembly away from the conductors, thereby reducing load-shift error and producing more accurate current readings for ground-fault sensing. The enclosure has two half members that are secured together to form a toroid-shaped shell that surrounds a toroidal core of the current sensor. A secondary winding and an optional test winding is wound around the toroidal core, and the ends of these windings exit one or more apertures formed in the enclosure. The half members have rounded profiles where the flat surfaces transition into different planes so that the magnetic flux does not encounter any sharp edges or transitions inside the enclosure as the flux flows away from the conductors.

Current sensor for earth leakage module

An assembly and method is provided for a tripping mechanism of an circuit breaker to limit the damage to a protected circuit breaker and other associated equipment such as enclosures, bus way, etc. from the high forces that result from high currents and prevent unwanted tripping of a circuit breaker due to rapidly decreasing currents. A trip system for a circuit breaker including a sensor to determine a rate of change in the current level. A positive detector is connected to the sensor to determine a positive current direction. A negative detector is connected to the sensor to determine a negative current direction. An electronic switch connected to the positive and negative sensors to activate the tripping mechanism of the circuit breaker. A power supply is connected to the tripping mechanism and electronic switch. Preferably a current delimiter applies a high voltage initially to an inductive device such as a tripping solenoid to effect a quick response but then limit the current to prevent damage to the tripping solenoid.

Quick responding instantaneous trip system

A compact coil assembly is provided for protecting electrical components from transient voltage surges. The assembly includes a bobbin having a cylindrical core with two ends. A first and second flange are each perpendicularly mounted and extended outwardly from one of the ends. A lead pin is perpendicularly upstanding on the top surface of the first flange. The first flange has a parallel outer and inner wall defining a channel therebetween. The inner wall has a slot therethrough. The slot is open at one end to the top surface of the first flange and extends downward to the core. The slot is positioned on the top surface of the first flange opposite the lead pin. The channel extends from the lead pin across to the end of the slot near the core. The width of the channel and the slot are adapted for guiding a winding wire therethrough.

Compact coil assembly for transient voltage protection

A voltage-to-frequency converter is provided for generating a frequency which is proportional to the square of the input voltage provided to the converter. Since the input voltage is correlative to current flowing in a conductor, the output frequency exhibits a proportionality similar to the relationship between the temperature of the conductor and the current flowing in it. The arrangement includes two charging circuits which receive the input voltage and are alternately charged as a function of the input voltage. While the first charging circuit charges to a predetermined voltage, the second charging circuit discharges. Upon exceeding the predetermined voltage, the output of a flip flop is set to discharge the first charging circuit, and to charge the second charging circuit. When the second charging circuit charges to a predetermined voltage, the output of the flip flop is reset, so that the first charging circuit charges again. As the input voltage rises, the charging time for each circuit decreases, thus causing the output of the flip flop to switch at a higher frequency. In effect, the frequency of the output of the flip flop changes at a rate proportional to the square of the input voltage.

Voltage-to-frequency squared circuit

A power supply incorporating a fault detection circuit controlling a circuit breaker is described. The power supply is isolated from relatively large applied DC voltages. This isolation is provided by a coupling capacitor in each of the line leads. The tripping energy for the circuit breaker can be provided either directly from the full wave rectifier output, or directly from the line lead or leads. In the case of the former, a reservoir capacitor may be used for storage of charge for tripping of the circuit breaker.

Power supply incorporating circuit breaker and fault detection circuit

An improved power supply is provided for circuit breaker applications and draws power from the power lines which the associated circuit breaker protects. The alternating current on the power lines is sensed by a current transformer and rectified by a full-wave rectifier. The full-wave rectified signal is alternately switched between a low impedance path, which does not provide power to the power supply, and a charging path, which does provide power to the power supply. During the major portion of the a.c. cycle, the full-wave rectified signal follows the low impedance path without loading the current transformer or distoring the current signal. However, near the zero crossings of the a.c. current signal, the low impedance path is opened so that the full-wave rectified signal charges a charging circuit. The charging circuit feeds a voltage regulator to provide output power from the power supply. While the rectified signal flows through the low impedance path, the charging circuit discharges and provides the power required by the peripheral circuitry of the circuit breaker. When the charge in the charging circuit drops below a predetermined set point, which is governed by the output of the regulator and feedback from the rectified signal, power is diverted from the low impedance path to recharge the charging circuit.

Fault-powered power supply

A loss of neutral or ground protection circuit is disclosed which uses a simple capacitive circuit which discharges through the neutral or ground leads in normal conditions, and in the event of loss of neutral or ground charges sufficiently to trip a circuit breaker. The protection circuit may include other circuits such as ground fault detection circuits and may be in a one or three phase system. By virtue of the fact that a capacitive circuit is used to trip the circuit breaker, an inherent time delay is involved and thus the circuit breaker will not be tripped as a result of a momentary loss of neutral or ground. This is particularly important where continuity of operation of a load is important.

Loss of neutral or ground protection circuit

A field installable motor operator for a circuit breaker includes a bidirectionally controllable motor that is coupled through a torque limited module to a circuit breaker operating mechanism. The motor is bidirectionally driven by a transistor switching bridge that supplies output current in reversible flow directions through one of the windings of the motor to the input of a rectifier bridge that supplies the other winding with currents that flow in the same direction. The torque limited module includes a centering and spacing ring which precisely confines the clutch elements to provide consistent torque. The motor is supplied with a current pulse of 250 milliseconds duration that is longer than the time required to fully operate the breaker. The clutch slips when breaker operation is completed and permits the motor to overrun without damage.

Field installable electrical operator for a circuit breaker

Electronic control circuit for a bidirectional motor

A plug-in power supply includes a housing dimensioned to fit into a space designed to accept a circuit breaker in a load center to provide D.C. power from an A.C. main power. The housing encloses a circuit card that has components that are connected between A.C. inlet terminals and D.C. output terminals to provide a peak current for a short duration, limit the output to a D.C. voltage maximum, and interrupt the output current when the output voltage drops below a certain level.

Plug-in power supply

An add on ground fault detection system including a module readily connected to the distribution line and to the associated circuit breaker, and including circuit means for sensing a metering signal while providing a low resistance burden to summing transformers, and providing a relay tripping signal if the metering signal is above a selected level.

Add-on ground fault module

A high saturation three coil current transformer for use with electrical apparatus having a U-shaped conductor portion. The current transformer has a ferromagnetic core surrounding one leg of the U-shaped conductor. The core is formed from two U-shaped core portions. A first coil and a second coil are wound on bobbins, with one bobbin being placed around each juncture between the core portions. A third coil is wound about the middle section of one of the U-shaped core portions prior to the core portions being joined. The current transformer is positioned so that the U-shaped conductor surrounds the third coil.

High saturation three coil current transformer

An electrical circuit to signal a circuit breaker to trip when the circuit breaker is closed and a high level fault occurs or when a low level fault occurs while the breaker is in the process of closing. A mechanical switch tied to the breaker contacts deactivates the low level trip function when the contacts are closed. A high level overcurrent causes a trigger diode to conduct current, energizing an opto-coupler that causes the trip solenoid to trip the breaker. The circuit also causes the breaker to trip if a sustained medium level overcurrent exists.

Growing community of inventors

Alburnett, IA, United States of America

Henry J Zylstra