Outlet and device boxes that enclose devices or utilization equipment shall have a minimum internal depth that accommodates the rearward projection of the equipment and the size of the conductors that supply the equipment. The internal depth shall include that of any extension boxes, plaster rings, or raised covers. The internal depth shall comply with all of the applicable provisions that follow: [314.24(B)] 1. **Large equipment.** Boxes that enclose devices or utilization equipment that projects more than 1⁷/₈ inches (48 mm) rearward from the mounting plane of the box shall have a depth that is not less than the depth of the equipment plus ¹/₄ inch (6.4 mm). [314.24(B)(1)] 2. **Conductors larger than 4 AWG.** Boxes that enclose devices or utilization equipment supplied by conductors larger than 4 AWG shall be identified for their specific function. Devices or utilization equipment supplied by conductors larger than 4 AWG shall be permitted to be mounted on or in junction and pull boxes larger than 100 cubic inches (1650 cm³) if the spacing at the terminals meets the requirements of Section E3907.9. [314.24(B)(2) and Exception] 3. **Conductors 8, 6, or 4 AWG.** Boxes that enclose devices or utilization equipment supplied by 8, 6, or 4 AWG conductors shall have an internal depth that is not less than 2¹/₁₆ inches (52.4 mm). [314.24(B)(3)] 4. **Conductors 12 or 10 AWG.** Boxes that enclose devices or utilization equipment supplied by 12 or 10 AWG conductors shall have an internal depth that is not less than 1³/₁₆ inches (30.2 mm). Where the equipment projects rearward from the mounting plane of the box by more than 1 inch (25.4 mm), the box shall have a depth that is not less than that of the equipment plus ¹/₄ inch (6.4 mm). Where wiring enters the center portion of the rear of a box opposite to the equipment, the minimum clearance shall be increased by ¹/₂ inch (12.7 mm). [314.24(B)(4)] 5. **Conductors 14 AWG and smaller.** Boxes that enclose devices or utilization equipment supplied by 14 AWG or smaller conductors shall have a depth that is not less than ¹⁵/₁₆ inch (23.8 mm). [314.24(B)(5)] **Exception:** Under any of the conditions specified in Items 1 through 5, devices or utilization equipment that is listed to be installed with specified boxes shall be permitted. [314.24(B)(1)–(5) Exception]

Chapter 39·Power And Lighting Distribution

Receptacle outlets that are part of a luminaire or appliance are generally considered to be:

According to the IRC, which of the following is NOT considered a 'wall space' for the purpose of general purpose receptacle distribution?

Regarding small-appliance branch circuits in a dwelling unit, which of the following statements is true?

A kitchen wall countertop has a sink that creates a wall area directly behind it. This area is 20 inches wide. Is a receptacle outlet required in this 20-inch wide area directly behind the sink?

A dwelling unit has a back deck accessible from inside that is 2 inches (51 mm) horizontally from the dwelling unit wall. What is the maximum height above the deck surface for the required receptacle outlet?

49 more questions in this chapter

Chapter 39Power And Lighting Distribution