HAZARDOUS ENVIRONMENT ELECTRICAL FEEDBACK BARRIER DEVICE, ASSEMBLY, SYSTEM AND METHOD

20240283193

18/638338

April 17, 2024

An electrical feedback barrier is configured to safely interconnect an intrinsically safe power supply to a non-intrinsically safe electrical load device in a hazardous environment. Electrical feedback from the non-intrinsically electrical load device is blocked by the electrical feedback barrier to protect the intrinsically safe power supply from adverse operating conditions. The electrical feedback barrier and the electrical load device are enclosed in an explosion-proof or flameproof enclosure for compliance with electrical equipment safety standards in the hazardous environment.

1. An electrical power system for a hazardous environment comprising: an explosion-proof or flameproof enclosure; an electrical feedback barrier and a non-intrinsically safe electrical load device each provided in the explosion-proof enclosure and being electrically connected to one another; and wherein the electrical feedback barrier is operative to isolate electrical feedback from the non-intrinsically safe electrical load device from reaching an intrinsically safe power supply remotely located from but connected to the electrical feedback barrier, thereby preventing an unsafe operation of the intrinsically safe power supply in the hazardous environment.

2. The electrical power system of claim 1, wherein the electrical feedback barrier is mounted stationary inside the explosion-proof or flameproof enclosure, whereby electrical feedback from the at least one non-intrinsically safe load device is safely contained within the explosion-proof or flameproof enclosure.

3. The electrical power system of claim 1, wherein the electrical feedback barrier is connected to earth ground through the explosion-proof or flameproof enclosure and is operative to isolate the intrinsically safe power supply from the at least one non-intrinsically safe load device and prevent electrical feedback from reaching the at least one intrinsically safe power supply by shunting the electrical feedback to earth ground.

4. The electrical power system of claim 3, wherein the at least one non-intrinsically safe load device is a low power consumption device selected from the group of a closed circuit television (CCTV) camera, a sensor, an instrumentation component, and a monitoring component.

5. The electrical power system of claim 3, wherein the electrical feedback barrier comprises: series-connected active elements conducting forward current from the intrinsically safe power supply to the non-intrinsically safe load device and preventing reverse current flow from the non-intrinsically safe load device to the intrinsically safe power supply; and parallel-connected active elements operative to shunt electrical feedback to electrical ground when electrical feedback generated by capacitive or inductive elements in the non-intrinsically safe electrical load device is presented on the electrical feedback barrier.

6. The electrical power system of claim 5, wherein the series-connected active elements and the parallel-connected active elements are Zener diodes or Schottky diodes.

7. A method of safely powering a non-intrinsically safe electrical load device from an intrinsically safe power supply in a hazardous environment, the method implemented with an electrical feedback barrier configured to protect the intrinsically safe power supply from electrical feedback produced by the non-intrinsically safe electrical load device; wherein the electrical feedback barrier includes an input connected to the intrinsically safe power supply in the hazardous environment, an output connected to the non-intrinsically safe electrical load device in the hazardous environment, and a connection to earth ground; the method comprising: passing an energy limited current and voltage from the intrinsically safe power supply through the electrical feedback barrier to the non-intrinsically safe electrical load device; and shunting, via the feedback barrier, electrical feedback generated in the operation of the non-intrinsically safe electrical load device to electrical ground in order to protect the intrinsically safe power supply from reaching an unsafe condition in the hazardous environment.

8. The method of claim 7, further comprising mounting the feedback barrier and the non-intrinsically safe electrical load device within an explosion-proof or flameproof enclosure.

9. The method of claim 7, further comprising selecting the non-intrinsically safe electrical load device from the group consisting of a closed circuit television (CCTV) camera, a sensor, an instrumentation component, and a monitoring component.

10. The method of claim 7, wherein passing an energy limited current and voltage from the intrinsically safe power supply through the electrical feedback barrier to the non-intrinsically safe electrical load device comprises operating a pair of series-connected diodes connected between the input and output of the electrical feedback barrier.

11. The method of claim 10, wherein shunting, via the feedback barrier, electrical feedback generated in the operation of the non-intrinsically safe electrical load device to electrical ground in order to protect the intrinsically safe power supply from reaching an unsafe condition in the hazardous environment comprises operating a pair of parallel-connected diodes connected to the output, the operation of the pair of parallel-connected diodes being responsive to a voltage increase on the output to divert electrical feedback energy to earth ground.

12. A method of safely powering a non-intrinsically safe electrical load device from an intrinsically safe power supply in a hazardous environment, the method implemented with an electrical feedback barrier configured to protect the intrinsically safe power supply from electrical feedback produced by the non-intrinsically safe electrical load device; wherein the electrical feedback barrier includes an input connected to the intrinsically safe power supply in the hazardous environment, an output connected to the non-intrinsically safe electrical load device in the hazardous environment, and a connection to earth ground; the method comprising: passing an energy limited current and voltage from the intrinsically safe power supply through the electrical feedback barrier to the non-intrinsically safe electrical load device; and shunting, via the feedback barrier, electrical feedback generated in the operation of the non-intrinsically safe electrical load device to electrical ground in order to protect the intrinsically safe power supply from reaching an unsafe condition in the hazardous environment.

13. The method of claim 12, further comprising mounting the feedback barrier and the non-intrinsically safe electrical load device within an explosion-proof or flameproof enclosure.

14. The method of claim 12, further comprising selecting the non-intrinsically safe electrical load device from the group consisting of a closed circuit television (CCTV) camera, a sensor, an instrumentation component, and a monitoring component.

15. The method of claim 12, wherein passing an energy limited current and voltage from the intrinsically safe power supply through the electrical feedback barrier to the non-intrinsically safe electrical load device comprises operating a pair of series-connected diodes connected between the input and output of the electrical feedback barrier.

16. The method of claim 12, wherein shunting, via the feedback barrier, electrical feedback generated in the operation of the non-intrinsically safe electrical load device to electrical ground in order to protect the intrinsically safe power supply from reaching an unsafe condition in the hazardous environment comprises operating a pair of parallel-connected diodes connected to the output, the operation of the pair of parallel-connected diodes being responsive to a voltage increase on the output to divert electrical feedback energy to earth ground.

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edspap.20240283193