ELECTRICAL LOAD CENTER
First Claim
1. In a load center for distributing electrical power from electrical power utility lines to multiple branch circuits via a load center bus connected to said utility lines, each of the branch circuits having a circuit breaker coupled to a signal processor that is shared by all the circuit breakers of the multiple branch circuits, a low voltage DC power supply comprisinga switch mode low voltage power supply connected to said processor for supplying said processor with a DC power input, anda line-derived power supply and a fault-derived power supply coupled between said utility and said switch mode power supply for supplying DC inputs to said switch mode power supply,said line-derived power supply including (1) a step-down transformer coupled to the utility lines for producing a stepped-down AC voltage, and (2) a rectifier for converting said stepped-down AC voltage to a first DC power input for said switch mode low voltage power supply, andsaid fault-derived power supply including (1) a pair of current transformers on said utility lines for producing alternating signals proportional to the currents flowing in the utility lines connected to the load center bus, and (2) rectifiers for converting the alternating signals produced by said current transformers to a second DC power input for said switch mode low voltage power supply.
2 Assignments
0 Petitions
Accused Products
Abstract
A low voltage DC power supply is provided in a load center for distributing electrical power from electrical power utility lines to multiple branch circuits via a load center bus connected to the utility lines, each of the branch circuits having a circuit breaker coupled to a processor that is shared by multiple circuit breakers in the load center. The low voltage DC power supply includes a switch mode low voltage power supply connected to the processor for supplying the processor with a DC power input, and a line-derived power supply and a fault-derived power supply coupled between the utility and the switch mode power supply for supplying DC inputs to the switch mode power supply. The magnitude of electrical current supplied to the multiple branch circuits from the load center bus is determined by producing signals representing the current levels in the bus at successive locations on opposite sides of each connection of the bus to the multiple branch circuits, and determining the current supplied to each branch circuits from those signals.
22 Citations
16 Claims
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1. In a load center for distributing electrical power from electrical power utility lines to multiple branch circuits via a load center bus connected to said utility lines, each of the branch circuits having a circuit breaker coupled to a signal processor that is shared by all the circuit breakers of the multiple branch circuits, a low voltage DC power supply comprising
a switch mode low voltage power supply connected to said processor for supplying said processor with a DC power input, and a line-derived power supply and a fault-derived power supply coupled between said utility and said switch mode power supply for supplying DC inputs to said switch mode power supply, said line-derived power supply including (1) a step-down transformer coupled to the utility lines for producing a stepped-down AC voltage, and (2) a rectifier for converting said stepped-down AC voltage to a first DC power input for said switch mode low voltage power supply, and said fault-derived power supply including (1) a pair of current transformers on said utility lines for producing alternating signals proportional to the currents flowing in the utility lines connected to the load center bus, and (2) rectifiers for converting the alternating signals produced by said current transformers to a second DC power input for said switch mode low voltage power supply.
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7. In a load center for distributing electrical power from electrical power utility lines to multiple branch circuits, comprising
a load center bus connecting said utility lines to said multiple branch circuits, a circuit breaker in each of said multiple branch circuits, detectors coupled to said load center bus for producing signals representing the current levels in said bus at successive locations on opposite sides of each connection of said bus to said multiple branch circuits and supplying said signals to said signal processor, and a signal processor receiving said signals produced by said detectors and programmed to use said signals to determine the current supplied to each of said branch circuits, said signal processor producing trip signals for all said circuit breakers.
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10. A method of supplying low voltage DC power to a signal processor in a load center for distributing electrical power from electrical power utility lines to multiple branch circuits via a load center bus, each of the branch circuits having a circuit breaker coupled to said signal processor, said method comprising
supplying said signal processor with a DC power input from a switch mode low voltage power supply, and supplying DC inputs to said switch mode power supply from a line-derived power supply and a fault-derived power supply coupled between said utility and said switch mode power supply, producing a stepped-down AC voltage from said utility lines in said line-derived power supply, and converting said stepped-down AC voltage to a first DC power input for said switch mode low voltage power supply, and producing alternating signals proportional to the currents flowing in the utility lines connected to the load center bus in said fault-derived power supply, and converting the alternating signals produced by said current transformers to a second DC power input for said switch mode low voltage power supply.
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14. A method of determining the magnitude of electrical current supplied to multiple branch circuits from a load center bus in a load center connected to electrical power utility lines, said method comprising
producing signals representing the current levels in said bus at successive locations on opposite sides of each connection of said bus to said multiple branch circuits, and determining the current supplied to each of said branch circuits from said signals.
Specification