Keeping up with the requirements of the Code should be the goal of everyone involved in electrical safety. Here is this month's newsletter with what I feel is an important rule in the 2017 NEC^®, complete with graphics and a video. I encourage you to use it as a training resource for your organization, and share it with your colleagues.

The content below is extracted from Mike Holt's Understanding the 2017 National Electrical Code^®, Volume 1.
Any underlined text denotes a change to the Code for the 2017 NEC.

(A) Mounting. Faceplates for switches must be installed so they completely cover the outlet box opening and, where flush mounted, the faceplate must seat against the wall surface.

(B) Grounding. The metal mounting yokes for switches, dimmers, and similar control switches must be connected to an equipment grounding conductor. Metal faceplates must be grounded. Snap switches are considered to be part of an effective ground-fault current path if either of the following conditions is met:

(1) Metal Boxes. The switch is mounted with metal screws to a metal box or a metal cover that's connected to an equipment grounding conductor in accordance with 250.148. â–¶Figure 404“23

â–¶Figure 404“23

Author's Comment:

Direct metal-to-metal contact between the device yoke of a switch and the box isn't required. â–¶Figure 404“24

â–¶Figure 404“24

(2) Nonmetallic Boxes. The grounding terminal of the switch yoke must be connected to the circuit equipment grounding conductor. â–¶Figure 404“25

â–¶Figure 404“25

Ex 1: The metal mounting yoke of a replacement switch isn't required to be connected to an equipment grounding conductor if the wiring at the existing switch doesn't contain an equipment grounding conductor and the switch faceplate is nonmetallic with nonmetallic screws, or the replacement switch is GFCI protected. Ex 2: Listed assemblies aren't required to be connected to an equipment grounding conductor if all of the following conditions are met: (1) The device is provided with a nonmetallic faceplate that can't be installed on any other type of device, (2) The device doesn't have mounting means to accept other configurations of faceplates, (3) The device is equipped with a nonmetallic yoke, and (4) Parts of the device that are accessible after installation of the faceplate are manufactured of nonmetallic material. Ex 3: A snap switch with an integral nonmetallic enclosure complying with 300.15(E).

We'd love to hear from you about this series, and the ways you're using it. Send us your comments and feedback by clicking on Post a Comment below. Look out for the next part in this series a month from now, and please share with your colleagues.

This content is extracted from Mike Holt's Illustrated Guide to Understanding the 2017 National Electrical Code, Volume 1 textbook.
To review or catch up on previous newsletters on the National Electrical Code click here.

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