General Electric Company

Paul H Singer

John A Pollman

Raymond K Seymour

Paul T Rajotte

Esteban Santos

Mark J Obermeier

Alan Joseph Messerli

David Arnold

Michael Roger Koller

Indrajit Purkayastha

Hanns P Sailer

George R Ribar, Jr

Dennis L Ericson

A method of initializing short time and groundfault protection heat index accumulators to compensate for current flow during the time interval between the application of phase current and application of current measurement and protection algorithms in an electronic trip unit is presented. The electronic trip unit includes a microcontroller and associated ROM having trip unit application code, e.g., main functionality firmware, including initializing parameters, and boot code, stored therein and EEPROM having operational parameter code, e.g., encoded enumerations for parameters such as 50/60 Hz., UL/ANSI/IEC, etc., stored therein. The time internal comprises first and second time components. The first time component is the time between the instant phase currents are applied and the instant the microcontroller is initialized and the second time component is the time between the instant the microcontroller is initialized and the instant the microcontroller begins execution of short time and groundfault algorithms (i.e., protection algorithms). The first time component is approximated by applying an initial current measurement to index a calibrator. The second time component is measured by a counter controlled by the initialization firmware. The first and second time components are applied to the initial current measurement (or a derivative thereof) to determine an initial value (or a component thereof), for short time and/or groundfault heat index accumulators.

Method for initializing short time and groundfault protection heat index

A method for error detection and correction in an electronic trip unit is presented. The electronic trip unit includes a ROM having trip unit application code, e.g., main functionality firmware, including initializing parameters, and boot code, stored therein and an EEPROM having operational parameter code, e.g., encoded enumerations for parameters such as 50/60 Hz., UL/ANSI/IEC, ect., stored therein The integrity of the code is monitored using CRC or checksum. Corrupted data is recovered by using encoded enumerations with at least two repetitive bit patterns of appropriate width. Encoding enumerations with greater that two repetitive bit patterns allows for each enumerated value to be recovered from any single bit corruption by replacing the corrupted pattern with the matching pattern. Alternatively, with a plurality of encoded enumeration groups stored in the EEPROM a corrupted enumeration can be properly selected and corrected by cross correlating the enumeration groups. Also, enumerations can be encoded with two identical bit patterns. An invalid bit pattern is then replaced with the other corresponding bit pattern, thereby restoring the bit pattern. The correct enumeration can then be identified, as one of the bit patterns continues to have the correct encoded enumeration identifying an enumeration.

Method for error detection and correction in a trip unit

The idea behind this algorithm is to provide prioritized data in an optimal sequence to expedite initialization/activation of ordered processes necessary to effect circuit protection functionality from a circuit breaker trip unit.

Circuit breaker trip unit processor initialization program

A ground fault/rating plug for molded case circuit breakers is inserted within the circuit breaker cover for electrical connection with the circuit breaker electronic trip unit. A rating resistor within the ground fault/rating plug enclosure sets the circuit breaker ampere rating. Rotary switches on the outer surface of the ground fault/rating plug enclosure configures the trip unit for ground fault protection.

Ground fault-rating plug for molded case circuit breakers

A circuit breaker trip unit enclosure is adapted to receive rotary knobs that are limited in rotation in proportion to the circuit breaker short circuit rating. The externally-accessible rotary knobs extend within the enclosure to contact with a potentiometer affixed to the circuit breaker trip unit printed circuit board. A stop member is inserted within the enclosure access opening to detent the rotary knob shank that extends through the access opening.

Circuit breaker electronic trip unit with adjustable settings

Each pole of a multi-pole circuit breaker is equipped to individually separate the circuit breaker contacts within each pole upon overcurrent occurrence. A digital processor within the circuit breaker trip unit determines the occurrence of zero current crossing of phase current within the individual poles and initiates contact separation at zero current values.

Zero current circuit interruption

A remote closing operator is positioned within a circuit breaker enclosure to allow remote operation of the circuit breaker operating mechanism to close the circuit breaker contacts. A closing solenoid and associated logic circuit controls the state of the contact closing springs. The solenoid is energized to initially release the contact closing springs and is later prevented from operation upon any further attempt to release the contact closing springs after the contacts are closed.

Circuit breaker remote closing operator

An integrated circuit breaker is described having shunt trip capability along with automatic overcurrent protection through the circuit breaker trip unit and shunt trip module. The shunt trip module further provides auxiliary power to the trip unit and allows the trip unit microprocessor to report and record the shunt trip operation.

Digital circuit interrupter shunt trip accessory module

This invention relates to a high ampere-rated circuit breaker which meets the electrical code requirements of the world market. The circuit breaker electronic trip unit is contained within a recess in the circuit breaker cover and is interlocked with the circuit breaker operating mechanism to articulate the operating mechanism upon removal. The accessory units are contained within an adjoining accessory compartment recess within the circuit breaker cover. Rejection pins on the accessories insure that the correct accessories are connected within the corresponding accessory compartments.

Accessory compartment for high ampere-rated circuit breaker

An integrated circuit breaker is described having undervoltage trip capability along with automatic overcurrent protection. The undervoltage accessory further provides auxiliary power to the trip unit and allows the trip unit to report and record the undervoltage release operation.

Digital circuit interrupter undervoltage release accessory

A combined bell alarm and lock-out accessory is connected with the electronic trip unit that controls a high ampere rated circuit breaker. The accessory interacts with the circuit breaker operating mechanism to activate the bell alarm upon circuit interruption and to prevent the closing of the circuit breaker contacts until the accessory is manually reset.

Bell alarm and lock-out for high ampere-rated circuit breakers

An integrated circuit breaker having several accessory functions along with automatic overcurrent protection, allows selection between the various accessory functions in different combinations. Separate switches are arranged on the circuit breaker to allow factory as well as field selection of the accessory function combinations.

Digital circuit interrupter with multiple accessory function

A digital circuit interrupter utilizing current transformers for operating power is provided with a re-chargeable battery to power-up the trip unit as well as to power the display after an overcurrent trip occurrence to enable an operator to determine both the magnitude as well as the cause of the overcurrent condition.

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West Hartford, CT, United States of America

Paul H Singer