GFCI that cannot be reset until wired correctly on line side and power is applied

• US 7,889,465 B2
• Filed: 04/07/2009
• Issued: 02/15/2011
• Est. Priority Date: 05/09/2002
• Status: Expired due to Fees

• Current Assignee: Hubbell, Inc.
• Original Assignee: Hubbell, Inc.
• Inventors: Bonilla, Nelson, DeBartolo, Joseph V. Jr.
• Primary Examiner(s): Leja; Ronald W
• Application Number:
  US12/385,394
• Publication Number:
  US 20090262470A1
• Time in Patent Office: 679 Days
• Field of Search: 361/42
• US Class Current: 361/42
• CPC Class Codes: H01H 83/04 with testing means for indicating the ability of the switch or relay to function properly
• CPC Class Codes: H02H 3/338 also responsive to wiring error, e.g. loss of neutral, break

Abstract

An apparatus and method for preventing the miswiring of a protection device. The protection device includes line terminals and load terminals. The protection device further includes a latching mechanism, adapted to move between a closed state which establishes electrical contact between said line and load terminals, and an open state which prevents electrical contact between said line and load terminals; and an initial reset prevention mechanism, adapted to prevent said latching mechanism from being set in said closed state until power is applied to said line terminals.

Claims

1. A protection device comprising:

line, load and user accessible face terminals;

a latching mechanism movable between a closed state providing electrical contact between said line, load and face terminals and an open state disconnecting electrical contact between said line, load and face terminals;

a miswiring protection circuit adapted to open-circuit when power is applied to the line terminals; and

an initial reset prevention mechanism movable between a first position preventing said latching mechanism from being set in said closed state and a second position permitting said latching mechanism to be set in said closed state when said miswiring protection circuit is open-circuited.

2. A protection device according to claim 1, further comprising an alarm indicator, providing an indication that the protection device is not providing ground fault protection.

3. A protection device according to claim 2, wherein said alarm indicator is a bicolor Light Emitting Diode (LED).

4. A protection device according to claim 3, wherein the LED flashes red to indicate the device is not providing ground fault protection.

5. A protection device according to claim 2, wherein said miswiring protection circuit is connected between a hot line terminal of the device and a neutral line terminal of the device.

6. A protection device according to claim 1, wherein said protection device is non-operational when powered from the load terminals prior to being powered from the line terminals.

7. A protection device according to claim 2, wherein said alarm indicator comprises a Light Emitting Diode (LED).

8. A protection device according to claim 2, wherein said alarm indicator comprises an audible indicator.

9. A method of preventing miswiring of a protection device having line, load and face terminals, the method comprising the steps of:

moving a latching mechanism between a closed state establishing electrical contact between said line, load and face terminals, and an open state prevents electrical contact between said line, load and face terminals;

conducting current in a miswiring protection circuit configured in a conductive path between a solenoid of the protection device and one of the line terminals;

preventing said latching mechanism from remaining in said closed state when an initial reset prevention mechanism is in a first position;

generating an open-circuit in said miswiring protection circuit when AC power is applied to the line terminals;

moving the initial reset prevention mechanism to a second position when AC power is applied to the line terminals; and

permitting said latching mechanism to be set in said closed state when the initial reset prevention mechanism is in the second position.

10. A method according to claim 9, further comprising:

activating an alarm indicator when said protection device is not providing ground fault protection.

11. A method according to claim 10, wherein said alarm indicator is a bicolor Light Emitting Diode (LED).

12. A method according to claim 11, wherein the LED flashes red to indicate the device is not providing ground fault protection.

13. A method according to claim 10, wherein said alarm indicator comprises a Light Emitting Diode (LED).

14. A protection device comprising:

phase line, load and face terminals;

neutral line, load and face terminals;

a latching mechanism movable between a closed state establishing one or more of electrical contact between said phase line, load and face terminals and electrical contact between said neutral line, load and face terminals, and an open state disconnecting one or more of electrical contact between said phase line, load and face terminals and disconnecting electrical contact between said neutral line, load and face terminals;

the latching mechanism including,

a first switch assembly being in a phase current path between the phase line and phase load terminals and having a first switch contact, a second switch contact, and third and fourth dual-switch contacts disposed between said first and second switch contacts for selectively opening or closing the phase current path, the first and second switch contacts and the third and fourth dual-switch contacts being aligned in a single axis, and

a second switch assembly being in a neutral current path between the neutral line and neutral load terminals and having a fifth switch contact, a sixth switch contact, and seventh and eighth dual-switch contacts disposed between said fifth and sixth switch contacts for selectively opening or closing a second conductive path, the fifth and sixth switch contacts and the seventh and eighth dual-switch contacts being aligned in a single axis.

15. A protection device as claimed in claim 14, further comprising an alarm indicator, adapted to provide an indication that said protection device is not providing ground fault protection.

16. A protection device as claimed in claim 14, wherein said third and fourth dual-switch contacts comprise a first contact surface oriented along the single axis, and a second contact surface oriented in the opposite direction from said first surface along the single axis.

17. A protection device as claimed in claim 16, wherein said first and second contact surfaces are both part of a single unitary conductive contact structure attached to a movable end of a flexible conductive brush arm.

18. A protection device as claimed in claim 16, wherein the first contact surface of said third and forth dual-switch contacts faces the first switch contact of said first switch assembly and the second contact surface of said third and forth dual-switch contacts faces the second switch contact of said first switch assembly.

19. A protection device comprising:

hot line and load terminals;

neutral line and load terminals;

a sensor electrically coupled to the line and load terminals via a plurality of current paths, said sensor capable of detecting a difference in current flowing in the current paths and generate a current difference signal;

a fault detector electrically coupled to said sensor and operable to generate a fault signal based on the current difference signal;

a latching mechanism electrically coupling the line terminals and the load terminals in a reset state;

a miswiring protection circuit disposed between said hot line terminal and said neutral line terminal and including at least a solenoid and a switch such that current flowing through the solenoid when AC power is applied to the line terminals causes the switch to move to an open state; and

a miswire prevention mechanism operable to prevent said latching mechanism from maintaining the reset state when AC power is supplied to the load terminals.

20. The protection device as claimed in claim 19, further comprising a reset device, said reset device operable to place said latching mechanism into the reset state when AC power is supplied to the line terminals.

21. A ground fault circuit interrupter (GFCI) comprising:

a line terminal;

a load terminal;

a user accessible face terminal;

a resilient first cantilevered contact arm electrically connected to said line terminal at a fixed end of said first cantilevered contact arm and having a movable line electrical contact at a free end of said first cantilevered contact arm;

a resilient second cantilevered contact arm electrically connected to said load terminal at a fixed end of said second cantilevered contact arm and having a movable load electrical contact at a free end of said second cantilevered contact arm; and

a face electrical contact electrically connected to said user accessible face terminal, each of said load, line and face electrical contacts being substantially aligned along a common axis being electrically isolated from each other when the GFCI is in a tripped condition, and being electrically connected with each other when the GFCI is in a reset condition.

22. The GFCI recited in claim 21, wherein one of the line electrical contact and the load electrical contact is a dual-sided contact assembly having two contact surfaces located on opposite sides thereof, and

the other of the line and load contacts is a single-sided contact having a single contact surface located on one side of the respective electrical contact, and

a movable latch block engages at least one of said cantilevered contact arms to move the line electrical contact, the load electrical contact and the face electrical contact into electrical contact.

23. The GFCI recited in claim 22, wherein the respective electrical contact having said two contact surfaces comprises a single unitary conductive contact body.

24. The GFCI recited in claim 22, wherein a reset assembly including a user accessible reset button resets the GFCI.

25. The GFCI recited in claim 22, further comprising a current interrupting device configured to cause an open circuit condition when AC power is applied to said line terminal.

26. The GFCI recited in claim 25, wherein said current interrupting device includes a spring loaded conductive member in electrical contact with two opposing circuit contact points prior to AC power being applied to said line terminal and electrically disconnecting the two contact points when AC power is applied to said line terminal.

27. The GFCI recited in claim 22, further comprising a reset prevention mechanism that prevents the GFCI device from remaining in the reset condition until AC power has been applied to said line terminal.

28. The GFCI recited in claim 21, further comprising a wiring detection circuit generating an open circuit condition when the source of AC power is supplied to said line terminal.

29. A ground fault circuit interrupter (GFCI) comprising:

a housing;

at least one line terminal at least partially disposed within said housing;

at least one load terminal at least partially disposed within said housing;

at least one user accessible face terminal at least partially disposed within said housing;

a first flexible contact arm electrically connected to said line terminal at a first fixed end of said first flexible contact arm and having a line electrical contact adjacent a first free end of said first flexible contact arm;

a second flexible contact arm electrically connected to said load terminal at a second fixed end of said second flexible contact arm and having a load electrical contact adjacent a second free end of said second flexible contact arm; and

a face electrical contact electrically connected to said user accessible face terminal, said face electrical contact, said line electrical contact and said load electrical contact being substantially aligned along a common axis, said line electrical contact and said load electrical contact being movable along said common axis between a first position in which said line, load and face electrical contacts are electrically connected and a second position in which said line, load and face electrical contacts are spaced and electrically isolated from one another.

30. The GFCI recited in claim 29, wherein said at least one line terminal comprises a phase line terminal and a neutral line terminal, said at least one load terminal comprises a phase load terminal and a neutral load terminal and said at least one user accessible face terminal comprises a phase user accessible face terminal and a neutral user accessible face terminal.

31. The GFCI recited in claim 29, wherein,

said face electrical contact comprises a single contact surface facing the line and load electrical contacts;

one of the load electrical contact and the line electrical contact comprises a single contact surface facing said face electrical contact; and

the other of the load electrical contact and the line electrical contact includes two oppositely facing contact surfaces facing the face electrical contact and the one of the load and line electrical contacts, respectively.

32. The GFCI recited in claim 31, wherein,

the oppositely facing contact surfaces are on a single electrically conductive member connected to the respective flexible contact arm.

33. The GFCI recited in claim 29, wherein at least one of said first and second flexible contact anus comprises a vertical attachment portion at the fixed end thereof which is fixed to one of said line and load terminals, and a flexible portion disposed substantially perpendicular to said attachment portion.

34. The GFCI recited in claim 33, wherein said flexible portion comprises at least one bend such that the flexible portion is nonplanar.

35. A ground fault circuit interrupter (GFCI) comprising:

a housing;

phase and neutral line terminals at least partially disposed within said housing and connected to a source of AC power;

phase and neutral load terminals at least partially disposed within said housing and connected to a first electrical load;

phase and neutral user accessible face terminals at least partially disposed within said housing;

phase and neutral first flexible conductive contact arms having first ends being fixedly connected to said phase and neutral line terminals, respectively, and second ends each having a respective first electrical contact connected adjacent a respective free end thereof;

phase and neutral second flexible conductive contact arms having first ends being fixedly connected to said phase and neutral load terminals, respectively, and the second ends each having a respective second electrical contact adjacent a respective free end thereof; and

phase and neutral face electrical contacts electrically respectively connected to said phase and neutral user accessible face terminals and aligned substantially along phase and neutral axes with the respective first and second electrical contacts, the first and second contacts being movable along the respective axes between first positions in which the respective face, line and load electrical contacts are electrically connected and second positions in which the respective face, line and load contacts are spaced and electrically isolated from one another.

36. The GFCI recited in claim 35 further comprising:

a reset assembly at least partially disposed within said housing and including a reset pin;

a latch plate engaging at least the reset pin; and

a latch block assembly engaging at least one of said phase and neutral first flexible conductive contact arms and said phase and neutral second flexible conductive contact arms and said latch plate,

whereby when said reset assembly is activated the reset pin engages said latch plate and moves said latch block assembly towards each of said flexible contact arms such that the phase first electrical contact and the phase second electrical contact are moved to contact the phase face electrical contact, and the neutral first electrical contact and the neutral second electrical contact are moved to contact the neutral face electrical contact.