Open neutral detector

Patent metadata

Field	Value
Publication number	US-12088086-B2
Application number	US-202318334825-A
Country	US
Kind code	B2
Filing date	Jun 14, 2023
Priority date	Dec 9, 2016
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

Abstract

An apparatus for detecting an open neutral condition in a split phase power system is described. The apparatus includes two powered lines providing output electricity to an electrical distribution system and a shared neutral line providing a grounded neutral to the first and second powered lines. The apparatus is configured for detecting when an open neutral condition is present in the split phase power system by determining when a power current is present on one or both of the first and second powered lines while a return current is not present on the neutral line; and in response to detecting that the open neutral condition is present, causing an interrupter to interrupt the power supplied by the first and second powered lines or to generate a signal indicating an open condition.

First claim

The invention claimed is:

1. An apparatus for detecting an open neutral condition in a split phase power system for delivering power to an electrical distribution system of a Recreational Vehicle, the apparatus comprising:
a first powered line configured to output electricity to the electrical distribution system;
a second powered line configured to output electricity to the electrical distribution system;
a shared neutral line configured to provide a grounded neutral to the first and second powered lines;
an interrupter configured to selectively interrupt power supplied by the first and second powered lines; and
a controller configured for:
detecting when an open neutral condition is present in the split phase power system by determining instances when a power current is present on one or both of the first and second powered lines while a return current is not present on the neutral line; and
in response to detecting that the open neutral condition is present, causing the interrupter to interrupt the power supplied by the first and second powered lines.

2. The apparatus of claim 1 , wherein the controller comprises a processor, and wherein the processor is configured to execute stored instructions to determine when the open neutral condition is present in the split phase power system.

3. The apparatus of claim 2 , wherein the interrupter is communicatively coupled to the processor.

4. The apparatus of claim 2 , wherein the processor is communicatively coupled to one or more power monitors via one or more connections, wherein the one or more power monitors are configured to generate one or more electrical signals indicative of a first current on the first powered line and a second current on the second powered line, and the processor is configured to receive the one or more electrical signals generated by the one or more power monitors.

5. The apparatus of claim 4 , wherein the processor is configured to determine that a return current is not present on the neutral line based on the first current on the first powered line and the second current on the second powered line.

6. The apparatus of claim 5 , wherein the processor is configured to determine that a return current is not present on the neutral line by calculating a difference between the first current on the first powered line and the second current on the second powered line.

7. The apparatus of claim 4 , wherein the one or more electrical signals are further indicative of a third current on the neutral line, wherein the processor is configured to determine that the return current is not present on the neutral line by detecting instances when the third current is below a predefined threshold current value.

8. The apparatus of claim 1 , wherein determining that a return current is not present on the neutral line comprises detecting instances when a first current on the first powered line is equal to a second current on the second powered line.

9. The apparatus of claim 1 , wherein determining that a return current is not present on the neutral line comprises detecting instances when a third current on the neutral line is approximately zero.

10. The apparatus of claim 1 , wherein, causing the interrupter to interrupt the power supplied by the first and second powered lines comprises transmitting an interruption signal to one or more remote devices.

11. The apparatus of claim 1 , further comprising an indicator, wherein the controller is configured to cause an indication that the open neutral condition is.

12. The apparatus of claim 1 , wherein the first powered line, the second powered line, and the neutral line are connected to a Recreational Vehicle campground outlet configured to supply at least approximately fifty amps of electrical current.

13. A method for detecting an open neutral condition in a split phase power system for delivering power to an electrical distribution system of a Recreational Vehicle having a first powered line, a second powered line, and a shared neutral line, the method comprising:
detecting when an open neutral condition is present in the split phase power system by determining instances when a power current is present on one or both of the first and second powered lines while a return current is not present on the neutral line; and
interrupting the power supplied by the first and second powered lines in response to detecting that the open neutral condition is present.

14. The method of claim 13 , wherein detecting that the open neutral condition is present in the split phase power system comprises:
receiving, by a processor, one or more electrical signals indicative of a first current on the first powered line and a second current on the second powered line; and
executing, by the processor, stored instructions to determine that the open neutral condition is present.

15. The method of claim 13 , wherein determining that a return current is not present on the neutral line comprises detecting instances when a first current on the first powered line is equal to a second current on the second powered line.

16. The method of claim 13 , wherein determining that a return current is not present on the neutral line comprises detecting instances when a third current on the neutral line is below a predefined threshold current value.

17. The method of claim 13 , wherein determining that a return current is not present on the neutral line comprises detecting instances when a third current on the neutral line is approximately zero.

18. The method of claim 13 , wherein interrupting the power supplied by the first and second powered lines comprises transmitting an interruption signal to one or more remote devices.

19. The method of claim 13 , further comprising providing an indication that the open neutral condition is present after detecting the open neutral condition in the split phase power system.

20. The method of claim 13 , further comprising:
connecting the first powered line, the second powered line, and the neutral line to a Recreational Vehicle campground outlet configured to supply at least approximately fifty amps of electrical current.

Assignees

• Southwire Co Llc

Inventors

• Oldham Jr Donald Paul
• Moussa Hamze

Classifications

• H02H5/10

  responsive to mechanical injury, e.g. rupture of line, breakage of earth connection · CPC title

• H02H3/20

  responsive to excess voltage · CPC title

• H02H5/105

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

• H02H3/338 Primary

  also responsive to wiring error, e.g. loss of neutral, break · CPC title