The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 06, 2001
Filed:
May. 08, 1998
David J. Dunne, Cedar Rapids, IA (US);
Andy A. Haun, Cedar Rapids, IA (US);
Square D Company, Palatine, IL (US);
Abstract
A zone selective interlocking system for electronic trip circuit breakers includes a plurality of downstream terminals, each downstream terminal connecting with at least one of a plurality of downstream electronic trip circuit breakers having input terminals. A restraint input circuit module, including a voltage comparator, is connected to the input terminals of each of the downstream electronic trip circuit breakers and the input terminals are shorted together providing a self-restraint signal for each downstream electronic trip circuit breaker at the occurrence of a downstream fault condition. The system also includes a plurality of upstream terminals, each upstream terminal connecting with at least one of a plurality of upstream electronic trip circuit breakers having input terminals. The restraint input circuit module is connected to the input terminals of each of the upstream electronic trip circuit breakers for receiving a signal indicative of the downstream fault condition and wherein the restraint input circuit module is self-sourcing. An output circuit module including an opto-isolator is connected to each of the upstream electronic trip circuit breakers and each of the downstream electronic trip circuit breakers for providing galvanic isolation between circuit breakers in a restrained mode and circuit breakers in an unrestrained mode.