Remotely accessible electrical fault detection

• US 5,648,726 A
• Filed: 04/21/1995
• Issued: 07/15/1997
• Est. Priority Date: 04/21/1995
• Status: Expired due to Term

• Current Assignee: Thomas & Betts International LLC (ABB Limited)
• Original Assignee: Pacific Scientific Company Incorporated (Regal Rexnord Corp.)
• Inventors: Le, Anh V., Kilber, Jeffrey S.
• Primary Examiner(s): O'Shea, Sandra L.
• Assistant Examiner(s): Phillips, Roger
• Application Number:
  US08/425,879
• Time in Patent Office: 816 Days
• Field of Search: 324/72, 324/72.5, 324/457, 324/555, 324/556, 324/557, 324/558, 324/559, 324/500, 324/508, 324/509, 324/512, 324/522, 324/525, 324/534, 324/537, 324/538, 340/870.01, 340/870.02, 340/531, 340/657
• US Class Current: 324/555
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72
• CPC Class Codes: H02H 3/04 with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18

Abstract

The invention relates to a remotely accessible electrical fault detection system. According to one preferred embodiment, the system includes a weather-resistant housing having a mount adapted for mating to an aperture in an outer wall of a utility cabinet containing an electrical network; a circuit adapted for connection to the electrical network, wherein the circuit includes at least one of a transmitter and a receiver; and an antenna located inside the weather-resistant housing and coupled to the circuit. In operation, the transmitter can broadcast a radio frequency fault signal to a remote communication device, in response to the electrical network detecting a fault condition.

Claims

1. A remotely accessible outdoor electrical fault detection system for a utility cabinet enclosing at least one network for performing an electrical fault detection measurement, the cabinet having an external wall with an aperture, said system comprising

a weather-resistant housing having a mounting fitting adapted for mounting to the aperture of the external wall,

a circuit for electrical connection to the fault detection network and mounted inside said weather-resistant housing, said circuit including at least one of a transmitter and a receiver, and

an antenna located inside said weather-resistant housing and coupled to said circuit, for communicating between a location outside the cabinet and said circuit.

2. A system according to claim 1 wherein said weather-resistant housing is adapted to be substantially tamper proof.

3. A system according to claim 1 including means for orienting said antenna selectively within said weather-resistant housing to maximize at least one of range to which said antenna can effectively broadcast, and range from which said antenna can effectively receive.

4. A system according to claim 1 wherein said mounting fitting extends along a first axis, and wherein said system includes support means for orienting said antenna for radiating therefrom, outward from said weather-resistant housing, radio frequency energy having a polarization extending longitudinal to said axis.

5. A system according to claim 4 wherein the aperture in the outer wall is located in a first plane and wherein said support means orients said antenna in a second plane substantially perpendicular to said first plane.

6. A system according to claim 1 wherein the existing aperture is threaded and said mounting fitting of said weather-resistant housing is threaded to mate with the aperture.

7. A system according to claim 1 wherein said circuit is formed on a printed circuit board and said antenna is a microstrip antenna formed on said printed circuit board.

8. A system according to claim 1 wherein said circuit is formed on a printed circuit board and said weather-resistant housing comprises a first portion for structurally supporting said printed circuit board and an attachable second portion for coupling to said first portion in a weather-resistant fashion.

9. A system according to claim 7 wherein said weather-resistant housing has a radio transmissive wall.

10. A system according to claim 1 wherein said circuit includes means for receiving an electrical fault detection signal from said network, wherein said electrical fault detection signal is representative of a status of whether said network detects an electrical fault, and means for transmitting a radio signal representative of said status.

11. A system according to claim 1 wherein said circuit includes means for receiving temperature information from said network, wherein said temperature information is representative of an advance status of whether an electrical fault is developing, and means for transmitting a radio signal representative of said status.

12. A system according to claim 10 wherein said circuit includes means for transmitting a radio signal representative of a measurement of severity of a detected electrical fault.

13. A system according to claim 1 further comprising a remote communication device for communicating with said network by way of said antenna and said circuit, and wherein said circuit includes means for receiving an electrical fault detection signal from said network, wherein said electrical fault detection signal is representative of a status of whether said network detects an electrical fault, and means for transmitting a radio signal representative of said status to said remote communication device.

14. A system according to claim 13 wherein said remote communication device includes visual indicator means for alerting a technician to a detected electrical fault.

15. A system according to claim 14 wherein said circuit includes means for transmitting a radio signal to said remote communication device that is representative of a measurement of severity of a detected electrical fault.

16. A system according to claim 13 wherein said circuit includes means for receiving radio signals from said remote communication device.

17. A system according to claim 16 wherein said radio signals received from said mobile communication device are representative of requests for information regarding at least one of, whether said network detects an electrical fault and a measurement of severity of a detected electrical fault.

18. A device for facilitating remote access to an outdoor electrical fault detection network, said device comprising

a weather-resistant housing having a mount adapted for mating to an aperture formed in an outer wall of a utility cabinet containing an electrical network,

a circuit adapted for connection to an electrical network and mounted inside said weather-resistant housing, wherein said circuit includes at least one of a transmitter and a receiver, and

an antenna located inside said weather-resistant housing and coupled to said circuit for communicating between said circuit and the exterior of said housing.

19. A device according to claim 18 further comprising an orientation indicator visible on said housing and having a fixed location relative to a known orientation of said antenna within said housing.

20. A method of performing remotely accessible outdoor electrical fault detection comprising the steps of

enclosing at least one network for performing an electrical fault detection measurement in a utility cabinet having an external wall with an aperture,

mounting a weather-resistant housing to said aperture of said external wall,

electrically connecting a circuit to said network and mounting said circuit inside said weather-resistant housing, said circuit including at least one of a transmitter and a receiver, and

coupling an antenna to said circuit and locating said antenna inside said weather-resistant housing, for communicating between said circuit and the exterior of said housing.

21. A method according to claim 20 comprising the further step of selectively orienting said weather-resistant housing relative to said cabinet, for thereby selectively orienting said antenna.

22. A method of converting a non-remotely accessible outdoor electrical fault detection network contained in a utility cabinet into a remotely accessible electrical fault detection network, said method comprising the steps of

removing a fixture from a preexisting aperture in an outer wall of said utility cabinet,

providing access to said network by way of said preexisting aperture,

electrically connecting a circuit to said network by way of said access, wherein said circuit includes at least one of a transmitter and receiver,

coupling an antenna to said circuit,

mounting said circuit and said antenna in a substantially weather-resistant housing, and

mounting said housing to the preexisting aperture.

23. A method according to claim 22 comprising the further step of orienting said antenna to be substantially perpendicular to the outer wall.

24. A method according to claim 23 comprising the further steps of mounting said housing along a first axis extending perpendicularly from the outer wall, and orienting said antenna for radiating therefrom, outward from said housing, radio frequency energy having a polarization axis extending longitudinal to said first axis.

25. Circuit monitoring apparatus for remotely monitoring an operating parameter of an electrical cable, said parameter being detected within a weather resistant outdoor electrical utility cabinet, said apparatus comprising

a first mechanical fitting secured at an opening through a wall in the cabinet with a threaded connection through the cabinet wall,

a housing having a weatherproof body with a chamber therein and having a threaded mounting fitting secured to the body and extending along a first axis with a passage through the fitting communicating with the chamber, said mounting fitting being adapted for mounting in the opening through the cabinet wall with a threaded connection in place of the first mechanical fitting,

a radio antenna mounted within said chamber, and

antenna support means for orienting said antenna for radiating therefrom, outward from said body, radio frequency energy having a polarization axis extending longitudinal to said first axis.

26. Circuit monitoring apparatus according to claim 25 wherein said support means includes an electrical circuit board carrying an electrical conductor forming said antenna, and includes means for mounting said circuit board within said chamber oriented longitudinal with said first axis.

27. Circuit monitoring apparatus according to claim 25 wherein said housing is characterized by a maximum outer height H measured along said first axis and a maximum outer diameter D measured transverse to said axis, and wherein the ratio of H/D is less than approximately 1.3.