CA2267490A1 - Single pole arc fault circuit interrupter with miswire detection - Google Patents
Single pole arc fault circuit interrupter with miswire detection Download PDFInfo
- Publication number
- CA2267490A1 CA2267490A1 CA 2267490 CA2267490A CA2267490A1 CA 2267490 A1 CA2267490 A1 CA 2267490A1 CA 2267490 CA2267490 CA 2267490 CA 2267490 A CA2267490 A CA 2267490A CA 2267490 A1 CA2267490 A1 CA 2267490A1
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- CA
- Canada
- Prior art keywords
- arc
- terminal
- neutral
- circuit interrupter
- single pole
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- Abandoned
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Abstract
A single pole arc fault circuit interrupter with miswire detection includes a first terminal for connection to the hot line of a power source, a circuit interrupter connected to the first terminal; a second terminal for connection to the hot line of an electrical load; a third terminal for connection to a neutral line of a power source; a fourth terminal, connected to the third terminal for connection to the neutral line of an electrical load; a fifth terminal for connection to the ground line of an electrical power source; a circuit interrupter connected between the first terminal and the second terminal; an arc detector coupled in circuit relationship between the first terminal and the second terminal, the arc detector having an output for producing a signal when an arc is sensed; a neutral-ground potential detector connected between the third terminal and the fifth terminal, the neutral-ground potential detector having an output producing a signal when a voltage is detected between the third and fifth terminals; and a controller connected to the arc detector and the neutral-ground potential detector for operating the circuit interrupter for disconnecting the first terminal from the second terminal when either an arc is detected, as indicated by the presence of a signal at the output of the arc detector, or a hot/neutral reversal is detected as indicated by the presence of a signal at the output of the neutral-ground potential detector.
Description
SINGLE POLE ARC FAULT CIRCUIT INTERRUPTER
WITH MISWIRE DETECTION
Background of the Invention:
This invention relates generally to arc fault circuit interrupters and more particularly to a single pole arc fault circuit interrupter with miswire detection for detecting the reversal of the hot and neutral leads connected to the arc fault circuit interrupter.
There is an increasing recognition of the need for providing in circuit protection against arcing in the wiring circuits. Arc fault circuit interrupters of the type to which this invention pertains sense the initiation or presence of an arcing condition, and disconnect the electrical circuit in which the condition is detected.
Arcs can occur in electrical circuits between the hot wire and ground wire, or the hot wire and neutral wire. On occasion, electrical circuits are miswired with the hot and neutral wires reversed over all or part of the circuit. In order to ensure that arc faults are reliably detected, even if miswiring is present, known arc fault circuit interrupters must sense the presence of arcs between the hot line and either the neutral or ground line. This complicates the arc fault circuit interrupter, and increases its cost.
It is desirable to provide arc detection at the lowest possible cost, so as to promote the widest possible installation of arc fault circuit interrupters.
It is an object of this invention to provide an arc fault circuit interrupter that reliably detects arcing conditions in electrical circuits with a single pole device, and which also detects miswiring, specifically the reversal of the hot and neutral lines and disconnects the circuit if either an arc or a miswiring is sensed.
It is a further object of this invention to provide a single pole arc fault circuit interrupter with hot/neutral reversal detection circuitry that provides reliable arc fault detection at low cost. Briefly stated, and in accordance with a presently preferred embodiment of the invention, a single pole arc fault circuit interrupter with miswire detection includes a first terminal for connection to the hot conductor of a power source, a circuit interrupter connected to the first terminal;
a second terminal for connection to the hot conductor of an electrical load;
a third terminal for connection to a neutral conductor of a power source;
a fourth terminal, connected to the third terminal for connection to the neutral conductor of an electrical load;
a fifth terminal for connection to the ground conductor of an electrical power source;
a circuit interrupter connected between the first terminal and the second terminal;
an arc detector coupled in circuit relationship between the first terminal and the second terminal, the arc detector having an output for producing a signal when an arc is sensed;
15 a neutral-ground potential detector connected between the third terminal and the fifth terminal, the neutral-ground potential detector having an output producing a signal when a voltage is detected between the third and fifth terminals; and a controller connected to the arc detector and the neutral-ground 20 potential detector for operating the circuit interrupter for disconnecting the first terminal from the second terminal when either an arc is detected, as indicated by the presence of a signal at the output of the arc detector, or a hot/neutral reversal is detected as indicated by the presence of a signal at the output of the neutral-ground potential detector.
25 In accordance with another aspect of this invention, the single pole arc fault circuit interrupter with miswire detection includes a power supply connected between the first and third terminals.
In accordance with still another aspect of the invention, a single pole arc fault circuit interrupter with miswire detection includes a mis-wire 30 indicator connected between the third and fifth terminals.
In accordance with a still further aspect of the invention, a single pole arc fault circuit interrupter with miswire detection includes a reset switch connected to the arc detector for turning off the signal indicating the presence of an arc and resetting the detector.
WITH MISWIRE DETECTION
Background of the Invention:
This invention relates generally to arc fault circuit interrupters and more particularly to a single pole arc fault circuit interrupter with miswire detection for detecting the reversal of the hot and neutral leads connected to the arc fault circuit interrupter.
There is an increasing recognition of the need for providing in circuit protection against arcing in the wiring circuits. Arc fault circuit interrupters of the type to which this invention pertains sense the initiation or presence of an arcing condition, and disconnect the electrical circuit in which the condition is detected.
Arcs can occur in electrical circuits between the hot wire and ground wire, or the hot wire and neutral wire. On occasion, electrical circuits are miswired with the hot and neutral wires reversed over all or part of the circuit. In order to ensure that arc faults are reliably detected, even if miswiring is present, known arc fault circuit interrupters must sense the presence of arcs between the hot line and either the neutral or ground line. This complicates the arc fault circuit interrupter, and increases its cost.
It is desirable to provide arc detection at the lowest possible cost, so as to promote the widest possible installation of arc fault circuit interrupters.
It is an object of this invention to provide an arc fault circuit interrupter that reliably detects arcing conditions in electrical circuits with a single pole device, and which also detects miswiring, specifically the reversal of the hot and neutral lines and disconnects the circuit if either an arc or a miswiring is sensed.
It is a further object of this invention to provide a single pole arc fault circuit interrupter with hot/neutral reversal detection circuitry that provides reliable arc fault detection at low cost. Briefly stated, and in accordance with a presently preferred embodiment of the invention, a single pole arc fault circuit interrupter with miswire detection includes a first terminal for connection to the hot conductor of a power source, a circuit interrupter connected to the first terminal;
a second terminal for connection to the hot conductor of an electrical load;
a third terminal for connection to a neutral conductor of a power source;
a fourth terminal, connected to the third terminal for connection to the neutral conductor of an electrical load;
a fifth terminal for connection to the ground conductor of an electrical power source;
a circuit interrupter connected between the first terminal and the second terminal;
an arc detector coupled in circuit relationship between the first terminal and the second terminal, the arc detector having an output for producing a signal when an arc is sensed;
15 a neutral-ground potential detector connected between the third terminal and the fifth terminal, the neutral-ground potential detector having an output producing a signal when a voltage is detected between the third and fifth terminals; and a controller connected to the arc detector and the neutral-ground 20 potential detector for operating the circuit interrupter for disconnecting the first terminal from the second terminal when either an arc is detected, as indicated by the presence of a signal at the output of the arc detector, or a hot/neutral reversal is detected as indicated by the presence of a signal at the output of the neutral-ground potential detector.
25 In accordance with another aspect of this invention, the single pole arc fault circuit interrupter with miswire detection includes a power supply connected between the first and third terminals.
In accordance with still another aspect of the invention, a single pole arc fault circuit interrupter with miswire detection includes a mis-wire 30 indicator connected between the third and fifth terminals.
In accordance with a still further aspect of the invention, a single pole arc fault circuit interrupter with miswire detection includes a reset switch connected to the arc detector for turning off the signal indicating the presence of an arc and resetting the detector.
In accordance with another aspect of the invention, the arc detector comprises a transformer coupled between the first and second terminals.
Brief Description of the Drawings:
While the novel aspects of the invention are set forth with 5 particularity in the appended claims, the invention itself, together with further objects and advantages thereof may be more readily understood by reference to the following detailed description of a presently preferred embodiment thereof taken in connection with the accompanying drawing, in which:
10 Figure 1 is a schematic diagram, partially in block form, of a single pole arc fault circuit interrupter with miswire detection in accordance with this invention.
Detailed Description of a Preferred Embodiment of the Invention:
Refernng now to Figure 1, a single pole arc fault circuit interrupter 15 with hot/neutral reversal sensing is indicated generally at 10. The detector includes a first terminal 12 adapted to be connected to the hot conductor of a power source, and a second terminal 14 adapted to be connected to the hot conductor of an electrical load. A circuit interrupter 16, such as a relay 18 having normally open contacts 20 and a coil 22 is connected in circuit 20 relationship between terminals 12 and 14. An arc detector 24 includes a transformer 26, preferably having a toroidal core having as its primary an electrical conductor 28 extending through the core between the relay 16 and terminal 14, or between relay 16 and terminal 12, and a secondary 30 preferably comprising a large number of turns wound about the toroidal 25 core. The secondary 30 of the transformer 26 is connected to first and second inputs 32, 34 of an arc detector 36, which may be of any of the types known to those skilled in the art, and the details of which per se form no part of the invention, except in combination with the other elements as described herein.
30 A terminal 40 is adapted to be connected to the neutral conductor of the power source, and to another terminal 42 that is adapted to be connected to the neutral conductor of an electrical load. A further terminal 44 is adapted to be connected to the ground line of an electric power source and a load.
Brief Description of the Drawings:
While the novel aspects of the invention are set forth with 5 particularity in the appended claims, the invention itself, together with further objects and advantages thereof may be more readily understood by reference to the following detailed description of a presently preferred embodiment thereof taken in connection with the accompanying drawing, in which:
10 Figure 1 is a schematic diagram, partially in block form, of a single pole arc fault circuit interrupter with miswire detection in accordance with this invention.
Detailed Description of a Preferred Embodiment of the Invention:
Refernng now to Figure 1, a single pole arc fault circuit interrupter 15 with hot/neutral reversal sensing is indicated generally at 10. The detector includes a first terminal 12 adapted to be connected to the hot conductor of a power source, and a second terminal 14 adapted to be connected to the hot conductor of an electrical load. A circuit interrupter 16, such as a relay 18 having normally open contacts 20 and a coil 22 is connected in circuit 20 relationship between terminals 12 and 14. An arc detector 24 includes a transformer 26, preferably having a toroidal core having as its primary an electrical conductor 28 extending through the core between the relay 16 and terminal 14, or between relay 16 and terminal 12, and a secondary 30 preferably comprising a large number of turns wound about the toroidal 25 core. The secondary 30 of the transformer 26 is connected to first and second inputs 32, 34 of an arc detector 36, which may be of any of the types known to those skilled in the art, and the details of which per se form no part of the invention, except in combination with the other elements as described herein.
30 A terminal 40 is adapted to be connected to the neutral conductor of the power source, and to another terminal 42 that is adapted to be connected to the neutral conductor of an electrical load. A further terminal 44 is adapted to be connected to the ground line of an electric power source and a load.
A power supply 50 for providing convenient voltages, such as 5 volts for the logic circuits and 48 volts for the relay, and preferably using the neutral line 58 as circuit reference, has input terminals 52, 54 connected to the hot 56 and neutral 58 electrical conductors respectively.
5 The power supply 50 has two output terminals 60 and 62 respectively, with conductors not shown in Figure 1 for clarity, preferably with terminal 60 connected to one side of relay coil 22, and terminal 62 connected to the signal processing elements, but either of output power terminals 60 or 62 may be used as the power supply for the arc detector 10 circuit and neutral-ground potential detector circuit 36 and 66 respectively.
An indicator lamp 68, such as a neon lamp, is connected in series circuit relationship with a current limiting resistor 70 between the neutral and ground conductors 58 and 44 is the preferred embodiment, but an audible alarm, such as a piezo type alarm with associated circuitry as is I S commonly used in transient voltage detectors, may also be inserted between the neutral and ground conductors 58 and 44.
The neutral-ground potential detector 66 has input terminals 74, 76 connected to the neutral 58 and ground 44 lines respectively, and an output terminal 80 connected to an input 82 of a NORgate 64. The arc detector 36 20 has an output 86 connected to another input 88 of the NORgate 66 so that the presence of a high signal on either the output 86 of the arc detector 36 or the output 80 of the neutral-ground potential detector 66 or both will product a low signal at the output terminal 90 of the NORgate 64. The low output at 90 acts to pull the base 98 of the relay control transistor 96 25 low which disconnects relay coil 22 from the power supply 50 causing the contacts of relay 16 to open.
While the invention has been described in connection with a presently preferred embodiment thereof, those skilled in the art will recognize that certain modifications and changes may be made therein 30 without departing from the true spirit and scope of the invention, which accordingly is intended to be defined solely by the appended claims.
5 The power supply 50 has two output terminals 60 and 62 respectively, with conductors not shown in Figure 1 for clarity, preferably with terminal 60 connected to one side of relay coil 22, and terminal 62 connected to the signal processing elements, but either of output power terminals 60 or 62 may be used as the power supply for the arc detector 10 circuit and neutral-ground potential detector circuit 36 and 66 respectively.
An indicator lamp 68, such as a neon lamp, is connected in series circuit relationship with a current limiting resistor 70 between the neutral and ground conductors 58 and 44 is the preferred embodiment, but an audible alarm, such as a piezo type alarm with associated circuitry as is I S commonly used in transient voltage detectors, may also be inserted between the neutral and ground conductors 58 and 44.
The neutral-ground potential detector 66 has input terminals 74, 76 connected to the neutral 58 and ground 44 lines respectively, and an output terminal 80 connected to an input 82 of a NORgate 64. The arc detector 36 20 has an output 86 connected to another input 88 of the NORgate 66 so that the presence of a high signal on either the output 86 of the arc detector 36 or the output 80 of the neutral-ground potential detector 66 or both will product a low signal at the output terminal 90 of the NORgate 64. The low output at 90 acts to pull the base 98 of the relay control transistor 96 25 low which disconnects relay coil 22 from the power supply 50 causing the contacts of relay 16 to open.
While the invention has been described in connection with a presently preferred embodiment thereof, those skilled in the art will recognize that certain modifications and changes may be made therein 30 without departing from the true spirit and scope of the invention, which accordingly is intended to be defined solely by the appended claims.
Claims (17)
1. An arc fault circuit interrupter that reliably detects arcing conditions in electrical circuits, and which also detects miswiring, specifically the reversal of the hot and neutral conductors, and which interrupts the electrical circuit if either an arc or a miswiring is sensed, using a single pole device.
2. A single pole arc fault circuit interrupter with miswire detection comprising a first terminal for connection to the hot conductor of a power source, a circuit interrupter connected to the first terminal;
a second terminal for connection to the hot conductor of an electrical load;
a third terminal for connection to a neutral conductor of a power source;
a fourth terminal, connected to the third terminal for connection to the neutral conductor of an electrical load;
a fifth terminal for connection to the ground conductor of an electrical power source;
a circuit interrupter connected between the first terminal and the second terminal;
an arc detector coupled in circuit relationship between the first terminal and the second terminal, the arc detector having an output for producing a signal when an arc is sensed;
a neutral-ground potential detector connected between the third terminal and the fifth terminal, the neutral-ground potential detector having an output producing a signal when a voltage is detected between the third and fifth terminals; and a controller connected to the arc detector and the neutral-ground potential detector for operating the circuit interrupter for disconnecting the first terminal from the second terminal when either an arc is detected, as indicated by the presence of a signal at the output of the arc detector, or a hot/neutral reversal is detected as indicated by the presence of a signal at the output of the neutral-ground potential detector.
a second terminal for connection to the hot conductor of an electrical load;
a third terminal for connection to a neutral conductor of a power source;
a fourth terminal, connected to the third terminal for connection to the neutral conductor of an electrical load;
a fifth terminal for connection to the ground conductor of an electrical power source;
a circuit interrupter connected between the first terminal and the second terminal;
an arc detector coupled in circuit relationship between the first terminal and the second terminal, the arc detector having an output for producing a signal when an arc is sensed;
a neutral-ground potential detector connected between the third terminal and the fifth terminal, the neutral-ground potential detector having an output producing a signal when a voltage is detected between the third and fifth terminals; and a controller connected to the arc detector and the neutral-ground potential detector for operating the circuit interrupter for disconnecting the first terminal from the second terminal when either an arc is detected, as indicated by the presence of a signal at the output of the arc detector, or a hot/neutral reversal is detected as indicated by the presence of a signal at the output of the neutral-ground potential detector.
3. The single pole arc fault circuit interrupter with miswire detection of Claim 2, comprising a power supply connected between the first and third terminals.
4. The single pole arc fault circuit interrupter with miswire detection of Claim 2, comprising a miswire indicator connected between the third and fifth terminals.
5. The single pole arc fault circuit interrupter with miswire detection of Claim 2, comprising a reset switch connected to the arc detector for turning off the signal indicating the presence of an arc and resetting the detector.
6. The single pole arc fault circuit interrupter with miswire detection of Claim 2, in which the arc detector comprises a transformer coupled between the first and second terminals.
7. A single pole arc-fault circuit interrupter comprising:
a disconnect switch connected between an electrical source and a load;
a logic switch connected to the disconnect switch for opening the disconnect switch when a fault occurs;
an arc-fault detector coupled to a hot electrical conductor and having an output connected to the logic switch for signaling the logic switch to open the disconnect switch when an arc-fault is detected;
a neutral-ground potential detector connected between a neutral conductor and a ground conductor, and to the logic switch for signaling the logic switch to open the disconnect switch when a neutral-ground fault is detected.
a disconnect switch connected between an electrical source and a load;
a logic switch connected to the disconnect switch for opening the disconnect switch when a fault occurs;
an arc-fault detector coupled to a hot electrical conductor and having an output connected to the logic switch for signaling the logic switch to open the disconnect switch when an arc-fault is detected;
a neutral-ground potential detector connected between a neutral conductor and a ground conductor, and to the logic switch for signaling the logic switch to open the disconnect switch when a neutral-ground fault is detected.
8. The single pole arc-fault circuit interrupter of claim 7 in which the logic switch comprises a logic gate.
9. The single pole arc-fault circuit interrupter of claim 7 in which the logic switch comprises a NORgate having a first input connected to the arc-fault detector and a second input connected to the neutral-ground potential detector.
10. The single pole arc-fault circuit interrupter of claim 7 in which the disconnect switch comprises a relay.
11. The single pole arc-fault circuit interrupter of claim 7 comprising a visual indicator connected between the neutral and ground conductors for indicating the presence of a neutral-ground fault.
12. The single pole arc-fault circuit interrupter of claim 10 comprising a power supply connected to the logic gate and the relay.
13. The single pole arc-fault circuit interrupter of claim 10 comprising a switching transistor connected between the logic switch and the relay.
14. The single pole arc-fault circuit interrupter of claim 10 in which the relay comprises a normally open relay.
15. The single pole arc-fault circuit interrupter of claim 7 comprising an audible indicator connected between the neutral and ground conductors for indicating the presence of a neutral-ground fault.
16. The single pole arc-fault circuit interrupter of claim 4 where the miswire indicator is a visual indicator.
17. The single pole arc-fault circuit interrupter of claim 4 where the miswire indicator is an audible indicator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11347398A | 1998-07-10 | 1998-07-10 | |
| US09/113,473 | 1998-07-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2267490A1 true CA2267490A1 (en) | 2000-01-10 |
Family
ID=29709436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2267490 Abandoned CA2267490A1 (en) | 1998-07-10 | 1999-03-30 | Single pole arc fault circuit interrupter with miswire detection |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2267490A1 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6377427B1 (en) | 1995-03-13 | 2002-04-23 | Square D Company | Arc fault protected electrical receptacle |
| US6414829B1 (en) | 1998-02-19 | 2002-07-02 | Square D Company | Arc fault circuit interrupter |
| US6456471B1 (en) | 1998-02-19 | 2002-09-24 | Square D Company | Test, reset and communications operations in an ARC fault circuit interrupter with optional memory and/or backup power |
| US6477021B1 (en) | 1998-02-19 | 2002-11-05 | Square D Company | Blocking/inhibiting operation in an arc fault detection system |
| US6532424B1 (en) | 1995-03-13 | 2003-03-11 | Square D Company | Electrical fault detection circuit with dual-mode power supply |
| US6567250B1 (en) | 1998-02-19 | 2003-05-20 | Square D Company | Arc fault protected device |
| US6621669B1 (en) | 1998-02-19 | 2003-09-16 | Square D Company | Arc fault receptacle with a feed-through connection |
| US6625550B1 (en) | 1998-02-19 | 2003-09-23 | Square D Company | Arc fault detection for aircraft |
| US6782329B2 (en) | 1998-02-19 | 2004-08-24 | Square D Company | Detection of arcing faults using bifurcated wiring system |
-
1999
- 1999-03-30 CA CA 2267490 patent/CA2267490A1/en not_active Abandoned
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6377427B1 (en) | 1995-03-13 | 2002-04-23 | Square D Company | Arc fault protected electrical receptacle |
| US6532424B1 (en) | 1995-03-13 | 2003-03-11 | Square D Company | Electrical fault detection circuit with dual-mode power supply |
| US6414829B1 (en) | 1998-02-19 | 2002-07-02 | Square D Company | Arc fault circuit interrupter |
| US6456471B1 (en) | 1998-02-19 | 2002-09-24 | Square D Company | Test, reset and communications operations in an ARC fault circuit interrupter with optional memory and/or backup power |
| US6477021B1 (en) | 1998-02-19 | 2002-11-05 | Square D Company | Blocking/inhibiting operation in an arc fault detection system |
| US6567250B1 (en) | 1998-02-19 | 2003-05-20 | Square D Company | Arc fault protected device |
| US6621669B1 (en) | 1998-02-19 | 2003-09-16 | Square D Company | Arc fault receptacle with a feed-through connection |
| US6625550B1 (en) | 1998-02-19 | 2003-09-23 | Square D Company | Arc fault detection for aircraft |
| US6782329B2 (en) | 1998-02-19 | 2004-08-24 | Square D Company | Detection of arcing faults using bifurcated wiring system |
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