The new junction box and exposed work cover for the electrical outlet and light switch are prewired before installing in the attic. This project is continued from How to Wire an Attic Electrical Outlet and Light.

NEC 300.14 – Minimum Length of Conductors

I have to replace the old light switch and electrical outlet boxes by the attic stairway because the electrician cut off the ground wires, which are too short to make pigtail connections. Recall the wires must be at least 6 inches long at the box and extend at least 3 inches outside the box per NEC 300.14 requirements. To remedy this, a new 4 inch square junction box will be mounted a several inches lower on the 2×4 framing to expose at least 6 inches of NM-B 14/2 cable in the new junction box. I’ll also combine the convenience duplex outlet & toggle switch in the junction box using an exposed work cover. The 4 inch square junction box is highlighted in yellow in the wiring diagram:

4 inch Junction Box and Exposed Work Cover Wiring Diagram

4 inch Junction Box and Exposed Work Cover Wiring Diagram

Combining the duplex outlet and light switch in the square junction box will save space.

Exposed Work Cover for Electrical Outlet and Light Switch

It’s getting warm in the attic, so I decided to do all the pre-work I can in the workshop.

The electrical parts for the job are:

  • Raco 906C Exposed Work Cover for use with 4 inch square box
    for one Toggle Switch and one Duplex Receptacle. Available at Home Depot.
  • Leviton #5252 Heavy Duty Outlet 15 Amp, 125 Volts.
  • Leviton #CSB1 Single Pole Toggle Switch 20 Amp, 120/277 Volts.
  • 4in x 4in x 2-1/8in square steel junction box with stud mount bracket.
  • Halex #05103B 3/8in Clamp Connector for Non-Metallic Cable.
Junction Box, Exposed Work Cover, Light Switch and Duplex Outlet

Junction Box, Exposed Work Cover, Light Switch and Duplex Outlet

Electrical Outlet and Light Switch Break-away Ears

A minor problem is the duplex outlet and light switch will not fit inside the exposed work cover because the “ears” catch:

Electrical Outlet and Switch Don't Fit the Exposed Work Cover

Electrical Outlet and Switch Don’t Fit the Exposed Work Cover

The fix is simple: break off the switch and outlet ears by bending back-and-forth with a pliers. Note the stamped line at the base of break-away ears for this purpose:

Toggle Switch and Electrical Outlet: Break-away Ears

Toggle Switch and Electrical Outlet: Break-away Ears

Remove and discard the mounting screws included with the outlet and switch. The exposed work cover includes two Philips head screws that mate with the hex nuts. Use the flat head screws to mount the toggle switch as shown here:

Exposed Work Cover with Electrical Outlet and Light Switch Ears Removed

Exposed Work Cover with Electrical Outlet and Light Switch Ears Removed

After breaking off the ears, the duplex outlet and toggle switch will properly seat in the exposed work cover:

Electrical Outlet and Toggle Switch Seated in the Exposed Work Cover

Electrical Outlet and Toggle Switch Seated in the Exposed Work Cover

I’ve temporarily mounted the outlet and switch in the exposed work cover to illustrate the mounting:

Exposed Work Cover with Duplex Outlet and Light Switch

Exposed Work Cover with Duplex Outlet and Light Switch

The hex nuts are required for mounting electrical outlet in the exposed work cover:

Exposed Work Cover Rear View with Outlet and Switch

Exposed Work Cover Rear View with Outlet and Switch

The exposed work cover is 1/2 inch deep for extra room in the 4 inch square steel junction box:

Exposed Work Cover and 4 inch Square Junction Box

Exposed Work Cover and 4 inch Square Junction Box

The exposed work cover mounts to the 4 inch square junction box with the two junction box screws on opposite corners:

Exposed Work Cover Mounted to the Junction Box

Exposed Work Cover Mounted to the Junction Box

NM Cable Clamps

Two NM cable clamps are needed to protect and secure the NM-B 14/2 cable at the 4 inch square junction box. The Halex 3/8 inch cable clamps fit the 1/2 inch diameter knockouts (1/2″ K.O.) in the steel junction box. Two clamp connectors are required: one for the line-side cable (from the circuit breaker) and one for the load-side cable (to the attic light).

Junction Box, Knockouts and NM Cable Clamps

Junction Box, Knockouts and NM Cable Clamps

The 1/2 inch junction box knockouts are removed by firmly rapping the tip of screw driver on the edge opposite the metal tab to bend it open, then moving it back & forth with pliers a couple of times to break it free:

Steel Junction Box with 1/2 inch Knockouts

Steel Junction Box with 1/2 inch Knockouts

The NM cable clamps are attached to the junction box. I’ve also prewired the electrical outlet pigtails and toggle switch line-side and ground pigtails (reference the wiring diagram):

Light Switch and Duplex Outlet Exposed Work Cover & Junction Box

Light Switch and Duplex Outlet Exposed Work Cover & Junction Box

I’ll take the parts up to the attic for mounting and wiring in How to Wire an Attic Electrical Outlet and Light – Part 2.

Thanks for reading,

Bob Jackson

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