1. An interchangeable switching module for an electrical switching apparatus comprising a first enclosure, separable contacts and an operating mechanism structured to open and close said separable contacts, said interchangeable switching module comprising:
a second enclosure structured to fit within the first enclosure of said electrical switching apparatus; and
an interchangeable electrical circuit andor mechanical mechanism within the second enclosure and being structured to cooperate with switching of said separable contacts.
2. The interchangeable switching module of claim 1 wherein said interchangeable electrical circuit andor mechanical mechanism comprises a DC arc chamber or arc chute including two stacks of arc splitting plates and a permanent magnet.
3. The interchangeable switching module of claim 2 wherein said interchangeable electrical circuit andor mechanical mechanism further comprises a varistor electrically connected in parallel with a predetermined number of the arc splitting plates.
4. The interchangeable switching module of claim 2 wherein said interchangeable electrical circuit andor mechanical mechanism further comprises a transient suppressor selected from the group consisting of a number of MOVs, a varistor, and a resistorcapacitor network electrically connected in parallel with a predetermined number of the arc splitting plates.
5. An electrical switching apparatus comprising:
a first enclosure;
separable contacts;
an operating mechanism structured to open and close said separable contacts; and
an interchangeable switching module comprising:
a second enclosure structured to fit within said first enclosure, and
an interchangeable electrical circuit andor mechanical mechanism within the second enclosure and cooperating with switching of said separable contacts.
6. The electrical switching apparatus of claim 5 wherein said interchangeable electrical circuit andor mechanical mechanism comprises a DC arc chamber or arc chute including a stack of arc splitting plates and an air blower cooperating with said operating mechanism.
7. The electrical switching apparatus of claim 5 wherein said operating mechanism includes a trip mechanism structured to trip open said separable contacts; and wherein said interchangeable electrical circuit andor mechanical mechanism cooperates with said trip mechanism.
8. The electrical switching apparatus of claim 5 wherein said interchangeable electrical circuit andor mechanical mechanism comprises an insulator structured to slide between a contact scissors structure and a channel and force an arc therebetween to become relatively longer and be cooled by proximity to said insulator.
9. The electrical switching apparatus of claim 5 wherein said separable contacts are separable mechanical contacts; and wherein said interchangeable electrical circuit andor mechanical mechanism comprises a capacitor or a positive temperature coefficient device in parallel with said separable mechanical contacts.
10. The electrical switching apparatus of claim 5 wherein said separable contacts are separable mechanical contacts; and wherein said interchangeable electrical circuit andor mechanical mechanism comprises a solid state switching device in parallel with said separable mechanical contacts.
11. The electrical switching apparatus of claim 10 wherein said solid state switching device carries current flowing in a power circuit with less voltage drop than a corresponding voltage drop of said separable mechanical contacts; and wherein said state switching device and said separable mechanical contacts open to provide galvanic isolation to said power circuit.
12. The electrical switching apparatus of claim 10 wherein said interchangeable electrical circuit andor mechanical mechanism further comprises a point-on-wave controller cooperating with said operating mechanism to minimize arcing damage to said solid state switching device and said separable mechanical contacts.
13. The electrical switching apparatus of claim 12 wherein said controller comprises a processor, a current sensor, and a voltage sensor structured to switch said solid state switching device on and off at a particular point-on-wave of an alternating current power circuit.
14. The electrical switching apparatus of claim 5 wherein said interchangeable electrical circuit andor mechanical mechanism is structured to cooperate with switching of said separable contacts in series with an alternating current power circuit or a direct current power circuit.
15. The electrical switching apparatus of claim 5 wherein said electrical switching apparatus is selected from the group consisting of a switching device, a circuit breaker, a contactor, a manual motor starter, a relay, and a safety switch.
16. The electrical switching apparatus of claim 5 wherein said interchangeable electrical circuit andor mechanical mechanism includes a number of first components; wherein said electrical switching apparatus further comprises a number of second components; and wherein the second enclosure drops into the first enclosure or said number of first components are welded or brazed to said number of second components.
17. The electrical switching apparatus of claim 16 wherein said separable contacts are within said first enclosure or said second enclosure.
18. An interchangeable switching module for an electrical switching apparatus comprising a first enclosure and an operating mechanism structured to open and close separable contacts, said interchangeable switching module comprising:
a second enclosure structured to fit within the first enclosure of said electrical switching apparatus; and
an interchangeable electrical circuit andor mechanical mechanism within the second enclosure, said interchangeable electrical circuit andor mechanical mechanism comprising said separable contacts.
19. The interchangeable switching module of claim 18 wherein said interchangeable electrical circuit andor mechanical mechanism further comprises an enclosed gas-filled arc chamber enclosing said separable contacts.
20. The interchangeable switching module of claim 18 wherein said separable contacts are a first switch within said second enclosure; and wherein said interchangeable electrical circuit andor mechanical mechanism further comprises a series combination of a second switch and a positive temperature coefficient device, said series combination being in parallel with said first switch.
21. The interchangeable switching module of claim 18 wherein said separable contacts are a first switch within said second enclosure; and wherein said interchangeable electrical circuit andor mechanical mechanism further comprises a second switch in series with said first switch and a positive temperature coefficient device in parallel with said second switch.
22. The interchangeable switching module of claim 18 wherein said separable contacts are a double break translational contact system within said second enclosure.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A sensor cable for surveying, comprising:
at least one pair of current sensor electrodes disposed along opposite sides of the sensor cable, wherein the at least one pair of current sensor electrodes is configured to detect current in an electromagnetic field transverse to an inline direction of the sensor cable; and
an amplifier configured to amplify the current in the electromagnetic field for detection by the electrode pair.
2. The sensor cable of claim 1, further comprising;
an inclinometer configured to measure an orientation of the at least one pair of current sensor electrodes relative to a horizontal plane.
3. The sensor cable of claim 2, wherein the orientation is used to convert the electric current to horizontal and vertical electric field strengths.
4. The sensor cable of claim 1, wherein the at least one pair of current sensor electrodes comprises:
a first pair of current sensor electrodes disposed along a first opposite sides of the cable and
a second pair of current sensor electrodes disposed along a second opposite sides of the cable substantially perpendicular to the first opposite sides; and
an inclinometer configured to measure an orientation of the first pair and the second pair relative to a horizontal plane.
5. The sensor cable of claim 1, wherein the at least one pair of current sensor electrodes is made of foil material.
6. The sensor cable of claim 1, wherein the at least one pair of current sensor electrodes is disposed outside the sensor cable.
7. The sensor cable of claim 1, further comprising:
a voltage potential electrode pair configured to detect a strength of the electromagnetic field in an inline direction of the cable.
8. The sensor cable of claim 7, further comprising:
a first sensor housing, comprising:
a first electrode of the voltage potential electrode pair;
a conductive gel surrounding the first electrode, wherein the conductive gel is configured to conduct electrical current to the first electrode and keep the first electrode moist; and
a first membrane surrounding the conductive gel, wherein the first membrane is configured to hold the conductive gel in contact with the first electrode and permit electric current to flow between a surrounding medium and the conductive gel; and
a second sensor housing, comprising:
a second electrode of the voltage potential electrode pair;
a conductive gel surrounding the second electrode, wherein the conductive gel is configured to conduct electrical current to the second electrode and keep the second electrode moist; and
a second membrane surrounding the conductive gel, wherein the second membrane is configured to hold the conductive gel in contact with the second electrode and permit electric current to flow between a surrounding medium and the conductive gel.
9. A marine electromagnetic survey system, comprising:
a source for generating an electromagnetic field in a subsurface area; and
a sensor cable comprising:
at least one pair of current sensor electrodes disposed along opposite sides of the sensor cable, wherein the at least one pair of current sensor electrodes is configured to detect an electric current in an electromagnetic field transverse to an inline direction of the sensor cable; and
an amplifier configured to amplify the electric current in the electromagnetic field for detection by the electrode pair.
10. The system of claim 9, wherein the source comprises magneto-telluric currents.
11. The system of claim 9, further comprising a vessel for towing the source.
12. The system of claim 9, wherein the sensor cable further comprises an inclinometer configured to measure an orientation of the at least one pair of current sensor electrodes relative to a horizontal plane.
13. The system of claim 9, wherein the sensor cable further comprises:
a housing, comprising:
one of more electrodes;
a conductive gel surrounding the one or more electrodes, wherein the conductive gel is configured to conduct electrical current to the one or more electrodes and keep the one or more electrodes moist; and
a membrane surrounding the conductive gel, wherein the membrane is configured to hold the conductive gel in contact with the one or more electrodes and permit electric current to flow between a surrounding medium and the conductive gel.
14. A method for conducting an electromagnetic survey, comprising:
deploying a sensor cable having at least one pair of current sensor electrodes disposed along opposite sides of the sensor cable;
measuring an electric current in an electromagnetic field transverse to an inline direction of the sensor cable using the at least one pair of current sensor electrodes; and
determining an electric field strength using the measured electric current.
15. The method of claim 14, wherein the electric field strength is determined according to E=I(\u03c3S), where E is the electric field strength, I is the measured electric current, S is the surface area of the at least one pair of current sensor electrodes and \u03c3 is the seawater conductivity.
16. The method of claim 14, further comprising amplifying the electric current.
17. The method of claim 14, further comprising measuring an orientation of the at least one pair of current sensor electrodes relative to a horizontal plane.
18. The method of claim 14, further comprising converting the electric current to horizontal and vertical electric field strengths.
19. The method of claim 14, wherein deploying the sensor cable comprises towing the cable over a subsurface area to be surveyed.
20. The method of claim 14, wherein deploying the sensor cable comprises placing the cable on a seabed over a subsurface area to be surveyed.
21. The method of claim 14, further comprising generating an electric current of about 0.1 to about 10 Hz, thereby creating the electromagnetic field.
22. The method of claim 14, further using the electric field strength for hydrocarbon exploration.
23. The method of claim 14, further using the electric field strength to derive an image of the electrical resistivity of a subsurface area.