# US 9,954,352 B2 · Power system including a circuit providing smart zone selective interlocking communication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,954,352 B2 - Document ID: US9954352B2 - Status: Granted - Kind: B2 - Application number: 15/193,504 - Filed: 2016-06-27 - Published: 2016-10-20 - Granted: 2018-04-24 - Earliest claimed: 2013-10-21 - Assignees: Eaton Intelligent Power Limited - Applicants: Eaton Corporation - Inventors: Robert Eugene Hulse - Web page: https://patentgrep.com/patent/US9954352B2 ## CPC - H02H 7/30: Staggered disconnection - H02H 7/262: {involving transmissions of switching or blocking orders} - G05B 2219/25416: Interrupt - G05B 2219/2639: Energy management, use maximum of cheap power, keep peak load low - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A power system includes main circuit interrupters each having a load output, feeder circuit interrupters, a number of tie circuit interrupters, and a circuit. The circuit is structured to block communication, at least when at least one of the tie circuit interrupters has an open state between a first and a second of the main circuit interrupters, of a zone selective interlocking output of one of the feeder circuit interrupters having a line input electrically connected to the load output of the first main circuit interrupter to a zone selective interlocking input of the second main circuit interrupter, and of a zone selective interlocking output of a different one of the feeder circuit interrupters having a line input electrically connected to the load output of the second main circuit interrupter to a zone selective interlocking input of the first main circuit interrupter. ## Claims ### Claim 1 A power system comprising: a plurality of main circuit interrupters, each of said main circuit interrupters including: a line input, a load output, and a zone selective interlocking input; a plurality of tie circuit interrupters, at least one of said tie circuit interrupters including: a first terminal electrically connected to the load output of a first one of said main circuit interrupters, a second terminal electrically connected to the load output of a different second one of said main circuit interrupters, separable contacts electrically connected between said first terminal and said second terminal, said separable contacts having an open state and a closed state, a zone selective interlocking input, and a zone selective interlocking output; a plurality of feeder circuit interrupters, each of said feeder circuit interrupters including: a line input electrically connected to the load output of one of said main circuit interrupters, a load output, and a zone selective interlocking output; and a circuit structured to block communication, at least when said at least one of said tie circuit interrupters is in its open state, of the zone selective interlocking output of one of the feeder circuit interrupters having the line input electrically connected to the load output of said first one of said main circuit interrupters to the zone selective interlocking input of said different second one of said main circuit interrupters. ### Claim 2 (depends on 1) The power system of claim 1 wherein said circuit is structured to also block communication, at least when said at least one of said tie circuit interrupters is in its open state, of the zone selective interlocking output of a different one of the feeder circuit interrupters having the line input electrically connected to the load output of said different second one of said main circuit interrupters to the zone selective interlocking input of said first one of said main circuit interrupters. ### Claim 3 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fifth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a sixth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 4 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a third auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a fourth auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 5 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 6 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second electrical connection between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 7 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second electrical connection between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 8 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second electrical connection between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 9 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second electrical connection between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 10 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said number of feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and an electrical connection between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 11 (depends on 2) The power system of claim 2 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; an electrical connection between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said number of feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 12 (depends on 2) The power system of claim 2 wherein said circuit comprises: an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; an electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 13 (depends on 2) The power system of claim 2 wherein said circuit comprises: an electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 14 (depends on 2) The power system of claim 2 wherein said main circuit interrupters, said number of tie circuit interrupters and said feeder circuit interrupters are low voltage switchgear. ### Claim 15 (depends on 3) The power system of claim 3 wherein the second and fourth diodes are structured to eliminate communication between the zone selective interlocking output of said different one of said feeder circuit interrupters on a power bus powered by said different second one of said main circuit interrupters and said first one of said main circuit interrupters that powers a different power bus for said one of said feeder circuit interrupters. ### Claim 16 (depends on 2) The power system of claim 2 wherein said power system is configured as a Main-Tie-Main power system and includes two faults reported by two of said first one and said different second one of said main circuit interrupters, said at least one of said number of tie circuit interrupters, and said one and said different one of said feeder circuit interrupters. ### Claim 17 (depends on 3) The power system of claim 3 wherein said first, second, third, fourth, fifth and sixth diodes are discrete diodes within a common enclosure, on a printed circuit board, or within an integrated circuit. ### Claim 18 (depends on 2) The power system of claim 2 wherein said main circuit interrupters, said number of tie circuit interrupters and said feeder circuit interrupters are circuit breakers. ### Claim 19 (depends on 2) The power system of claim 2 wherein said at least one of said number of tie circuit interrupters normally has the open state of said separable contacts between the first and second terminals thereof. ### Claim 20 (depends on 3) The power system of claim 3 wherein the first and second diodes are electrically connected together in series with a first conductor of a two-wire twisted pair, said first conductor being electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters. ### Claim 21 (depends on 20) The power system of claim 20 wherein a second conductor of the two-wire twisted pair is electrically connected to a ground or common. ### Claim 22 (depends on 21) The power system of claim 21 wherein each of said main circuit interrupters, said number of tie circuit interrupters and said feeder circuit interrupters further includes a terminal electrically connected to the second conductor of the two-wire twisted pair. ### Claim 23 (depends on 3) The power system of claim 3 wherein said first, second, third, fourth, fifth and sixth diodes are discrete diodes. ### Claim 24 (depends on 3) The power system of claim 3 wherein the second and fourth diodes prevent the zone selective interlocking output of said different one of said feeder circuit interrupters on a power bus powered by said different second one of said main circuit interrupters from being input by the zone selective interlocking input of said first one of said main circuit interrupters that powers a different power bus for said one of said feeder circuit interrupters. ### Claim 25 A circuit for controlling zone selective interlocking of a power system that includes (i) a plurality of main circuit interrupters, each of said main circuit interrupters including: a line input, a load output, and a zone selective interlocking input, (ii) a number of tie circuit interrupters, at least one of said tie circuit interrupters including: a first terminal electrically connected to the load output of a first one of said main circuit interrupters, a second terminal electrically connected to the load output of a different second one of said main circuit interrupters, separable contacts electrically connected between said first terminal and said second terminal, said separable contacts having an open state and a closed state, a zone selective interlocking input, and a zone selective interlocking output, and (iii) a plurality of feeder circuit interrupters, each of said feeder circuit interrupters including: a line input electrically connected to the load output of one of said main circuit interrupters, a load output, and a zone selective interlocking output, the circuit comprising: a first input structured to receive the zone selective interlocking output of said at least one of said tie circuit interrupters; a second input structured to receive the zone selective interlocking output of one of the feeder circuit interrupters having the line input electrically connected to the load output of said first one of said main circuit interrupters; a third input structured to receive the zone selective interlocking output of a different one of the feeder circuit interrupters having the line input electrically connected to the load output of said different second one of said main circuit interrupters; a first output structured to selectively communicate the zone selective interlocking output of the one of the feeder circuit interrupters having the line input electrically connected to the load output of said first one of said main circuit interrupters to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second output structured to selectively communicate the zone selective interlocking output of the different one of the feeder circuit interrupters having the line input electrically connected to the load output of said different second one of said main circuit interrupters to the zone selective interlocking input of said first one of said main circuit interrupters; wherein the circuit is structured to block communication, at least when said at least one of said tie circuit interrupters is in its open state, of the zone selective interlocking output of the one of the feeder circuit interrupters having the line input electrically connected to the load output of said first one of said main circuit interrupters to the zone selective interlocking input of said different second one of said main circuit interrupters. ### Claim 26 (depends on 25) The circuit of claim 25 wherein the circuit is structured to also block communication, at least when said at least one of said tie circuit interrupters is in its open state, of the zone selective interlocking output of the different one of the feeder circuit interrupters having the line input electrically connected to the load output of said different second one of said main circuit interrupters to the zone selective interlocking input of said first one of said main circuit interrupters. ### Claim 27 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fifth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a sixth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 28 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a third auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a fourth auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 29 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 30 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second electrical connection between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 31 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second electrical connection between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 32 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second electrical connection between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 33 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; a first auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second auxiliary contact having said state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a second electrical connection between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 34 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said one of said number of feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and an electrical connection between the zone selective interlocking output of said different one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 35 (depends on 25) The circuit of claim 25 wherein said circuit comprises: a first diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said at least one of said number of tie circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; an electrical connection between the zone selective interlocking output of said one of said feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said different one of said number of feeder circuit interrupters and the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 36 (depends on 25) The circuit of claim 25 wherein said circuit comprises: an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; an electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 37 (depends on 25) The circuit of claim 25 wherein said circuit comprises: an electrical connection between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said first one of said main circuit interrupters; an auxiliary contact having a state corresponding to the open state or the closed state of said separable contacts and electrically connected between the zone selective interlocking output of said at least one of said number of tie circuit interrupters and the zone selective interlocking input of said different second one of said main circuit interrupters; a first diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said first one of said main circuit interrupters; a second diode including an anode electrically connected to the zone selective interlocking output of said one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters; a third diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said different second one of said main circuit interrupters; and a fourth diode including an anode electrically connected to the zone selective interlocking output of said different one of said feeder circuit interrupters and a cathode electrically connected to the zone selective interlocking input of said at least one of said number of tie circuit interrupters. ### Claim 38 A method for controlling zone selective interlocking of a power system that includes (i) a plurality of main circuit interrupters, each of said main circuit interrupters including: a line input, a load output, and a zone selective interlocking input, (ii) a number of tie circuit interrupters, at least one of said tie circuit interrupters including: a first terminal electrically connected to the load output of a first one of said main circuit interrupters, a second terminal electrically connected to the load output of a different second one of said main circuit interrupters, separable contacts electrically connected between said first terminal and said second terminal, said separable contacts having an open state and a closed state, a zone selective interlocking input, and a zone selective interlocking output, and (iii) a plurality of feeder circuit interrupters, each of said feeder circuit interrupters including: a line input electrically connected to the load output of one of said main circuit interrupters, a load output, and a zone selective interlocking output, the method comprising: receiving the zone selective interlocking output of said at least one of said tie circuit interrupters; receiving the zone selective interlocking output of one of the feeder circuit interrupters having the line input electrically connected to the load output of said first one of said main circuit interrupters; receiving the zone selective interlocking output of a different one of the feeder circuit interrupters having the line input electrically connected to the load output of said different second one of said main circuit interrupters; selectively communicating the zone selective interlocking output of the one of the feeder circuit interrupters having the line input electrically connected to the load output of said first one of said main circuit interrupters to the zone selective interlocking input of said different second one of said main circuit interrupters; and selectively communicating the zone selective interlocking output of the different one of the feeder circuit interrupters having the line input electrically connected to the load output of said different second one of said main circuit interrupters to the zone selective interlocking input of said first one of said main circuit interrupters; wherein, at least when said at least one of said tie circuit interrupters is in its open state, communication of the zone selective interlocking output of the one of the feeder circuit interrupters having the line input electrically connected to the load output of said first one of said main circuit interrupters to the zone selective interlocking input of said different second one of said main circuit interrupters is blocked. ### Claim 39 (depends on 38) The circuit of claim 38 wherein, at least when said at least one of said tie circuit interrupters is in its open state, communication of the zone selective interlocking output of the different one of the feeder circuit interrupters having the line input electrically connected to the load output of said different second one of said main circuit interrupters to the zone selective interlocking input of said first one of said main circuit interrupters is blocked.