Circuit interrupting device for providing ground fault and open neutral protection in temporary power applications

Patent metadata

Field	Value
Publication number	US-11575255-B2
Application number	US-202117563765-A
Country	US
Kind code	B2
Filing date	Dec 28, 2021
Priority date	Nov 15, 2019
Publication date	Feb 7, 2023
Grant date	Feb 7, 2023

Abstract

A temporary power delivery system includes a power source, a booth stringer, and a portable GFCI device. The GFCI device is receives current from the power source by a first terminal and delivers current to the booth stringer by a second terminal. An electronic processor of the GFCI device compares a combined magnitude of current flowing through first and second phase conductors of the GFCI device to a magnitude of current flowing through a neutral conductor of the GFCI. The electronic processor also compares a first voltage between the first phase conductor and neutral conductor to a second voltage between the second phase conductor and neutral conductor. A circuit breaker of the GFCI device is opened if a difference between the combined magnitude of phase conductor current and neutral conductor current exceeds a first threshold or a difference between the first voltage and second voltage exceeds a second threshold.

First claim

What is claimed is:

1. A temporary power delivery system comprising:
a power source;
a portable power cord including at least one outlet; and
a ground fault circuit interrupter (GFCI) including:
a first terminal configured to receive power from the power source;
a second terminal configured to deliver power to the portable power cord;
a first phase conductor, a second phase conductor, and a neutral conductor;
a circuit breaker; and
an electronic processor configured to open the circuit breaker when a difference between a combined magnitude of current flowing through the first and second phase conductors and a magnitude of current flowing through the neutral conductor exceeds a first threshold.

2. The temporary power delivery system of claim 1 , wherein the electronic processor is further configured to determine that a ground fault has occurred when the difference between the combined magnitude of current flowing through the first and second phase conductors and the magnitude of current flowing through the neutral conductor exceeds the first threshold.

3. The temporary power delivery system of claim 1 , wherein the electronic processor is further configured to open the circuit breaker when a first voltage between the first phase conductor and the neutral conductor differs from a second voltage between the second phase conductor and the neutral conductor by more than a second threshold.

4. The temporary power delivery system of claim 3 , wherein the electronic processor is further configured to determine that an open neutral condition has occurred when the difference between the first voltage and the second voltage exceeds the second threshold.

5. The temporary power delivery system of claim 1 , wherein the portable power cord is a booth stringer.

6. The temporary power delivery system of claim 5 , wherein the GFCI device and the booth stringer are integrally formed as a single component of the temporary power delivery system.

7. The temporary power delivery power system of claim 1 , wherein the GFCI device is removably coupled to the power source and the portable power cord.

8. The temporary power delivery system of claim 7 , wherein the second terminal of the GFCI device includes a pigtail connector.

9. The temporary power delivery system of claim 7 , wherein the second terminal of the GFCI device includes a plug.

10. A method of operating a temporary power delivery system comprising:
receiving, by a first terminal of a ground fault circuit interrupter (GFCI) device, current from a power source;
delivering, by a second terminal of the GFCI device, current to a portable power cord;
supplying, by an outlet of the portable power cord, power to a load; and
interrupting current flow from the power source to the portable power cord, by a circuit breaker of the GFCI device, when a difference between a combined magnitude of current flowing through first and second phase conductors of the GFCI device and a magnitude of current flowing through a neutral conductor of the GFCI device exceeds a first threshold.

11. The method of claim 10 further comprising determining, by the electronic processor, that a ground fault has occurred when the difference between the combined magnitude of current flowing through the first and second phase conductors and the magnitude of current flowing through the neutral conductor exceeds the first threshold.

12. The method of claim 11 further comprising illuminating, by the electronic processor, a display of the GFCI device to indicate the occurrence of the ground fault.

13. The method of claim 10 further comprising interrupting current flow from the power source to the portable power cord, by the circuit breaker, when a first voltage between the first phase conductor and the neutral conductor differs from a second voltage between the second phase conductor and the neutral conductor by more than a second threshold.

14. The method of claim 13 further comprising determining, by the electronic processor, that an open neutral condition has occurred when the difference between the first voltage and the second voltage exceeds the second threshold.

15. The method of claim 14 further comprising illuminating, by the electronic processor, a display of the GFCI device to indicate the occurrence of the open neutral condition.

16. The method of claim 10 , wherein the portable power cord is a booth stringer.

17. A power system comprising:
a power source;
a booth stringer; and
a ground fault circuit interrupter (GFCI) including:
a first terminal configured to receive power from the power source;
a second terminal configured to deliver power to the booth stringer;
a first phase conductor, a second phase conductor, and a neutral conductor;
a circuit breaker; and
an electronic processor configured to open the circuit breaker when at least one of:
a difference between a combined magnitude of current flowing through the first and second phase conductors and a magnitude of current flowing through the neutral conductor exceeds a first threshold, and
a first voltage between the first phase conductor and the neutral conductor differs from a second voltage between the second phase conductor and the neutral conductor by more than a second threshold.

18. The power system of claim 17 , wherein the GFCI device and the booth stringer are integrally formed as a single component.

19. The power system of claim 17 , wherein the GFCI device is removably coupled, by the second terminal, to the booth stringer.

20. The power system of claim 17 , wherein the booth stringer is a 3-phase, 30 ampere booth stringer.

Assignees

• Hubbell Inc

Inventors

• Itzler Roy
• Gay Nicole

Classifications

• H02H3/34 Primary

  of a three-phase system · CPC title

• H02H5/105

  responsive to deterioration or interruption of earth connection (for preventing switching-on H02H11/001) · CPC title

• H02H3/347

  using summation current transformers · CPC title

• H02H3/325

  involving voltage comparison (H02H3/347 takes precedence) · CPC title

• H02H3/105

  responsive to excess current and fault current to earth · CPC title