Electrical connectors – With circuit conductors and safety grounding provision – Grounding to connector container or housing
Reexamination Certificate
1999-07-21
2001-09-18
Nguyen, Khiem (Department: 2839)
Electrical connectors
With circuit conductors and safety grounding provision
Grounding to connector container or housing
C439S624000, C200S051060
Reexamination Certificate
active
06290511
ABSTRACT:
FIELD OF THE PRESENT INVENTION
The present invention relates to the grounding of a plurality of electrical switches commonly used for controlling lighting in buildings.
BACKGROUND OF THE PRESENT INVENTION
Snap switches, including dimmer switches, are commonly used for controlling lighting in buildings. When more than one snap switch is provided at a particular location, the plurality of snap switches are mounted on a wiring box disposed in a wall and covered by a faceplate attached to the wiring box.
Section 380-9(b) of the revised National Electrical Code currently requires that each snap switch be grounded. This section additionally requires that each snap switch provide a means for grounding a metal faceplate of the wiring box. According to this section, a snap switch is considered to be effectively grounded if the snap switch is mounted with metal screws to a metal box or to a non-metallic box having integral means for grounding devices. Alternatively, the snap switch is considered to be effectively grounded if an equipment grounding conductor or equipment bonding jumper is connected to an equipment grounding terminal of the snap switch.
To comply with the revised code when installing snap switches in a non-metallic wiring box, the current industry practice is to connect the equipment grounding terminal of each snap switch to a common ground of the wiring box using an exposed solid copper wire. The common ground typically comprises a wiring nut to which each ground wire leading into the wiring box is connected.
A drawback to this current practice for grounding snap switches is that the possibility exists that an exposed solid copper wire leading from a snap switch to the grounding nut may inadvertently contact an unsheathed portion of a hot wire or a mounting screw of the hot wire, thereby resulting in a short circuit. The risk of a short circuit occurs when the snap switch is installed in or withdrawn from a wiring box, especially since the stiffness of the solid copper wire makes it difficult to manipulate for avoiding a short circuit. Furthermore, this risk significantly increases as the number of snap switches installed in the wiring box increases.
A need therefore exists for a better method of grounding snap switches in a wiring box which minimizes the risk of a short circuit.
SUMMARY OF THE PRESENT INVENTION
Briefly, the present invention includes a method for grounding a plurality of snap switches arranged in a wiring box to a common ground source including the steps of: connecting together the grounding terminal of each snap switch of the plurality of snap switches with sheathed connecting wires such that each grounding terminal of each snap switch of the plurality of snap switches is disposed in electrical communication only with the grounding terminal of each other snap switch of the plurality of snap switches, the electrical communication forming an electrical network; and, connecting with a sheathed lead grounding wire the electrical network to a common ground source of the wiring box such that each snap switch is grounded.
In a feature of the method of the present invention, the sheathed lead grounding wire is connected to a grounding terminal of a snap switch of the plurality of snap switches. In other features, the electrical network is connected to the ground source only by the sheathed lead grounding wire, and the grounding terminals of the snap switches are connected in series in the electrical network by the sheathed connecting wires.
The present invention also includes an electrical conducting apparatus for grounding a plurality of snap switches to a common ground source and an electrical switch apparatus in which a plurality of snap switches are grounded to a common ground source.
The electrical conducting apparatus includes a plurality of sheathed connecting wires. Each end of each sheathed connecting wire is retained within a crimped spade lug such that all sheathed connecting wires are disposed in electrical communication with one another. The plurality of sheathed connecting wires thereby form an electrical network. Each crimped spade lug is configured for attachment to a grounding terminal of a snap switch.
In the electrical conducting apparatus, at least one crimped spade lug includes not only the end of a single sheathed connecting wire retained therein, but also an end of a sheathed lead grounding wire, the sheathed lead grounding wire thereby being disposed in electrical communication with each of the sheathed connecting wires through the electrical network. The sheathed lead grounding wire includes an opposite end that is left unattached for later connection thereof to a common ground source, whereby the connecting wires are each grounded through the electrical network. In a feature of the electrical conducting apparatus, the crimped spade lugs are disposed in series relative to one another in the electrical network.
The electrical switch apparatus includes a wiring box and plurality of snap switches mounted to the wiring box. Furthermore, each snap switch includes a grounding terminal. The electrical switch apparatus also includes a plurality of sheathed connecting wires. The grounding terminal of each snap switch is connected by at least one sheathed connecting wire to a grounding terminal of another snap switch such that all grounding terminals of the snap switches are disposed in electrical connection with each other through the sheathed connecting wires. The apparatus also includes a sheathed lead grounding wire connecting the grounding terminal of one of the plurality of snap switches to a common ground source such that each snap switch of the electrical switch apparatus is grounded. Preferably, the common ground source comprises a wire nut to which at least one ground wire of a feed line leading into the wiring box is connected.
In a feature of the electrical switch apparatus, the grounding terminal of only one of the snap switches is connected to the common ground source by the sheathed lead grounding wire. In a further feature, the grounding terminals are connected by the sheathed connecting wires in series with each other.
REFERENCES:
patent: 4245880 (1981-01-01), Zimmerman, Jr. et al.
patent: 5630502 (1997-05-01), Kurek et al.
patent: 5826710 (1998-10-01), Kurek et al.
Blair Robert E.
Edwards Michael G.
Kennedy Covington Lobdell & Hickman LLP
Nguyen Khiem
LandOfFree
Grounding of snap switches in a wiring box does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Grounding of snap switches in a wiring box, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Grounding of snap switches in a wiring box will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2511246