GFCI with miswire protection having unitary receptacle and load conductors after proper installation

Patent metadata

Field	Value
Publication number	US-10153121-B2
Application number	US-29285508-A
Country	US
Kind code	B2
Filing date	Nov 26, 2008
Priority date	Nov 30, 2007
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

An improved GFCI device prevents miswiring. Load conductors are electrically isolated from receptacle conductors. Normally closed contacts are held open by a miswire prevention mechanism, such that if power is connected to the load contacts, power cannot be delivered to the GFCI device, the receptacle conductors or the line conductors. Once power is properly connected to the line conductors, a proper wiring detection circuit activates the miswire prevention mechanism to release the normally closed contacts, thereby electrically connecting the receptacle conductors and the load conductors. After proper installation, the receptacle conductors are preferably permanently connected to the load conductors. The device is preferably shipped in the reset state.

First claim

What is claimed is:

1. A ground fault circuit interrupting device for preventing miswiring during installation, the device comprising:
at least one line terminal;
at least one load terminal electrically isolated from the at least one line terminal when the device is in a tripped condition and electrically connected to the at least one line terminal when the device is in a reset condition;
at least one receptacle terminal electrically connected to one of a hot receptacle conductor and a neutral receptacle conductor and electrically isolated from the at least one load terminal prior to installation; and
a proper wiring detection circuit connected to said hot and neutral receptacle conductors that causes said receptacle terminal to become electrically connected to said load terminal only a first time a source of power is connected to said at least one line terminal at the same time the device is in the reset condition.

2. The ground fault circuit interrupting device of claim 1 , further comprising a fault detection circuit adapted to detect a fault condition, and cause the device to operate in the tripped condition upon the detection of said fault condition.

3. The ground fault circuit interrupting device of claim 2 , wherein said fault condition is a ground fault.

4. The ground fault circuit interrupting device of claim 1 , further comprising a miswire prevention mechanism; and wherein said proper wiring detection circuit activates said miswire prevention mechanism when a source of power is connected to said at least one line terminal.

5. The ground fault circuit interrupting device of claim 4 , wherein said receptacle terminal is adapted to move between a first position in which said receptacle terminal is electrically isolated from said load terminal and a second position in which said receptacle terminal is electrically connected to said load terminal, and said miswire prevention mechanism comprises a mechanical latch retaining said receptacle terminal in said first position, wherein activation of said proper wiring detection circuit causes said latch to move to a release position which allows said receptacle terminal to move from said first position to said second position.

6. The ground fault circuit interrupting device of claim 5 , further comprising a solenoid adapted to move said latch to said release position when said solenoid is energized.

7. The ground fault circuit interrupting device of claim 5 , wherein said mechanical latch comprises a bimetal strip adapted to move to said release position when heated.

8. The ground fault circuit interrupting device of claim 7 , wherein said proper wiring detection circuit comprises a heater element adapted to heat said bimetal strip upon activation.

9. The ground fault circuit interrupting device of claim 7 , wherein said proper wiring detection circuit causes a current to flow through said bimetal strip to heat said bimetal strip upon activation.

10. The ground fault circuit interrupting device of claim 5 , wherein said mechanical latch comprises a shape memory alloy element adapted to move to said release position when heated.

11. The ground fault circuit interrupting device of claim 10 , wherein said proper wiring detection circuit comprises a heater element adapted to heat said shape memory allow element upon activation.

12. The ground fault circuit interrupting device of claim 10 , wherein said proper wiring detection circuit causes a current to flow through said shape memory alloy element to heat said shape memory allow element upon activation.

13. The ground fault circuit interrupting device of claim 10 , wherein said shape memory alloy element comprises Nitinol.

14. The ground fault circuit interrupting device of claim 5 , wherein said receptacle terminal is elastically biased towards the second position.

15. The ground fault circuit interrupting device of claim 4 , wherein said receptacle terminal is adapted to move between a first position in which said receptacle terminal is electrically isolated from said load terminal and a second position in which said receptacle terminal is electrically connected to said load terminal, and said miswire prevention mechanism comprises a current destructible fuse retaining said receptacle terminal in said first position, wherein activation of said proper wiring detection circuit causes current to flow through said fuse until said fuse blows and mechanically releases said receptacle terminal to move from said first position to said second position.

16. The ground fault circuit interrupting device of claim 15 , wherein said receptacle terminal is elastically biased towards the second position.

17. The ground fault circuit interrupting device of claim 4 , wherein said receptacle terminal is adapted to move between a first position in which said receptacle terminal is electrically isolated from said load terminal and a second position in which said receptacle terminal is electrically connected to said load terminal, and said miswire prevention mechanism comprises a heat-deformable material attached to said receptacle terminal and retaining said receptacle terminal in said first position, wherein activation of said proper wiring detection circuit causes a heater element to heat said heat deformable material until said heat deformable material deforms and mechanically releases said receptacle terminal to move from said first position to said second position.

18. The ground fault circuit interrupting device of claim 17 , wherein said heat-deformable material comprises plastic.

19. The ground fault circuit interrupting device of claim 17 , wherein said receptacle terminal is elastically biased towards the second position.

20. The ground fault circuit interrupting device of claim 4 , wherein said receptacle terminal is adapted to move between a first position in which said receptacle terminal is electrically isolated from said load terminal and a second position in which said receptacle terminal is electrically connected to said load terminal, and said miswire prevention mechanism comprises a low temperature solder element retaining said receptacle terminal in said first position, and a heater element, wherein activation of said proper wiring detection circuit causes said heater element to heat said solder element until said solder element melts and mechanically releases said receptacle terminal to move from said first position to said second position.

21. The ground fault circuit interrupting device of claim 20 , wherein said receptacle terminal is elastically biased towards the second position.

22. The ground fault circuit interrupting device of claim 4 , wherein said receptacle terminal is adapted to move between a first position in which said receptacle terminal is electrically isolated from said load terminal and a second position in which said receptacle terminal is electrically connected to said load terminal, and said miswire prevention mechanism comprises a low temperature solder element retaining said receptacle terminal in said first position, wherein activation of said proper wiring detection circuit causes current to flow through said solder element to heat said solder element until said solder element melts and mechanically releases said receptacle terminal to move from said first position to said second position.

23. The ground fault circuit interrupting device of claim 22 , wherein said receptacle terminal is elastically biased towards the second position.

Assignees

• Goodsell John Phillip
• Mortun Sorin Ioan
• Fanzutti Robert
• Hubbell Inc

Inventors

• Goodsell John Phillip
• Mortun Sorin Ioan
• Fanzutti Robert

Classifications

• Y10T29/49826

  Assembling or joining · CPC title

• H02H3/338

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

• H01H83/04 Primary

  with testing means for indicating the ability of the switch or relay to function properly · CPC title