Electrical safety device miswire detection
First Claim
1. An electrical safety device comprising:
- a line connection input, the line connection input including a line live input and a line neutral input configured to receive an a.c. signal;
a differential current detector to be coupled with a control circuit configured to receive a sense signal from the differential current detector indicating an amount of current passing through the differential current detector on a live current path and a neutral current path;
the control circuit configured to form a test signal;
an interrupter output; and
circuitry to;
activate the test signal to cause at least a portion of the current passing through the differential current detector on one of the live current path and the neutral current path to circumvent the differential current detector;
compare, while the test signal is active, the sense signal to a threshold value;
activate the interrupter output in response to the sense signal not exceeding the threshold value to cause at least one of the live current path and the neutral current path to be interrupted;
determine a polarity of the sense signal in response to the sense signal exceeding the threshold value; and
activate the interrupter output in response to the sense signal having a polarity that is opposite to a polarity of the a.c. signal.
4 Assignments
0 Petitions
Accused Products
Abstract
Aspects of an electrical safety device that provides detection of miswiring of line and load connection pairs are presented. In an example, the device includes a differential current detector through which are routed a live current path and a neutral current path coupling the line and load connection pairs. The device also includes a selectable conducting path that, when selected, circumvents the differential current detector while coupling one of a line live connection to a load live connection or a line neutral connection to a load neutral connection of the connection pairs. The device further includes a control circuit that determines, via the differential current detector, while the conducting path is selected, a differential current defined by a difference in currents on the live and neutral current paths, and interrupts at least one of the live and neutral current paths in response to the differential current not exceeding a threshold value.
17 Citations
18 Claims
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1. An electrical safety device comprising:
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a line connection input, the line connection input including a line live input and a line neutral input configured to receive an a.c. signal; a differential current detector to be coupled with a control circuit configured to receive a sense signal from the differential current detector indicating an amount of current passing through the differential current detector on a live current path and a neutral current path; the control circuit configured to form a test signal; an interrupter output; and circuitry to; activate the test signal to cause at least a portion of the current passing through the differential current detector on one of the live current path and the neutral current path to circumvent the differential current detector; compare, while the test signal is active, the sense signal to a threshold value; activate the interrupter output in response to the sense signal not exceeding the threshold value to cause at least one of the live current path and the neutral current path to be interrupted; determine a polarity of the sense signal in response to the sense signal exceeding the threshold value; and activate the interrupter output in response to the sense signal having a polarity that is opposite to a polarity of the a.c. signal. - View Dependent Claims (2, 3, 4, 17, 18)
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5. An electrical safety device comprising:
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a live current path coupling a line live connection and a load live connection; a neutral current path coupling a line neutral connection and a load neutral connection; the line live and line neutral connections configured to receive an a.c. signal; a differential current detector through which the live current path and the neutral current path are routed; a selectable conducting path that, when selected, circumvents the differential current detector while shorting one of the line live connection to the load live connection or shorting the line neutral connection to the load neutral connection; and a control circuit to; select the selectable conducting path; determine, via the differential current detector, while the selectable conducting path is selected, a differential current defined by a difference between a first current on the live current path and a second current on the neutral current path; interrupt at least one of the live current path and the neutral current path in response to the differential current not exceeding a threshold value; determine a polarity of the differential current in response to the differential current exceeding the threshold value; and interrupt the at least one of the live current path and the neutral current path based on the polarity of the differential current being opposite of a polarity of the a.c. signal. - View Dependent Claims (6, 7, 8, 10, 11, 12, 13, 14, 15)
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9. An electrical safety device comprising:
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a live current path coupling a line live connection and a load live connection; a neutral current path coupling a line neutral connection and a load neutral connection; a load circuit coupled between the live current path and the neutral current path to provide an electrical load in response to a first control signal; the line live and line neutral connections configured to receive an a.c. signal; a differential current detector through which the live current path and the neutral current path are routed; a selectable conducting path that, when selected, circumvents the differential current detector while shorting one of the line live connection to the load live connection or shorting the line neutral connection to the load neutral connection; and a control circuit to; select the selectable conducting path; determine, via the differential current detector, while the selectable conducting path is selected, a differential current defined by a difference between a first current on the live current path and a second current on the neutral current path; interrupt at least one of the live current path and the neutral current path in response to the differential current not exceeding a threshold value; determine a polarity of the differential current in response to the differential current exceeding the threshold value; and interrupt the at least one of the live current path and the neutral current path based on the polarity of the differential current being opposite of a polarity of the a.c. signal; wherein the control circuit is to provide the first control signal to the load circuit while the selectable conducting path couples one of the line live connection to the load live connection or the line neutral connection to the load neutral connection.
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16. A method for detecting a miswiring of a line connection pair and a load connection pair of an electrical safety device, the method comprising:
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configuring a control circuit to circumvent at least a portion of an electrical current carried over one of a live current path and a neutral current path through the electrical safety device, the live current path connecting a line live connection of the line connection pair with a load live connection of the load connection pair, and the neutral current path connecting a line neutral connection of the line connection pair with a load neutral connection of the load connection pair wherein the line live connection and the line neutral connection are configured to be coupled to receive an a.c. signal; configuring the control circuit to determine, while circumventing the at least a portion of the electrical current, a differential current defined by a difference between the electrical current carried over the live current path and the electrical current carried over the neutral current path; configuring the control circuit to interrupt at least one of the live current path and the neutral current path in response to the differential current not exceeding a threshold value; configuring the control circuit to determine a polarity of the differential current in response to the differential current exceeding the threshold value; and configuring the control circuit to interrupt the at least one of the live current path and the neutral current path in response to the polarity of the differential current being opposite to a polarity of the a.c. signal.
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Specification