Article 406

Receptacles, Cord Connectors, and Attachment Plugs (Caps)

For receptacles controlled by an automatic control device, the marking shall be located on the receptacle face and visible after installation.

  1. Scope. This article covers the rating, type, and installa‐ tion of receptacles, cord connectors, and attachment plugs (cord caps).
  2. Definitions.Child Care Facility. A building or structure, or portion thereof, for educational, supervisory, or personal care services for more than four children 7 years old or less.imageNOutlet Box Hood. A housing shield intended to fit over a face‐ plate for flush-mounted wiring devices, or an integral compo‐ nent of an outlet box or of a faceplate for flush-mounted wiring devices. The hood does not serve to complete the elec‐ trical enclosure; it reduces the risk of water coming in contact with electrical components within the hood, such as attach‐ ment plugs, current taps, surge protective devices, direct plug- in transformer units, or wiring devices.
  3. Receptacle Rating and Type.
    1. Receptacles. Receptacles shall be listed and marked with the manufacturer’s name or identification and voltage and ampere ratings.
    2. Rating. Receptacles and cord connectors shall be rated not less than 15 amperes, 125 volts, or 15 amperes, 250 volts, and shall be of a type not suitable for use as lampholders.Informational Note: See 210.21(B) for receptacle ratings where installed on branch circuits.
    3. Receptacles for Aluminum Conductors. Receptacles rated 20 amperes or less and designed for the direct connection of aluminum conductors shall be marked CO/ALR.
    4. Isolated Ground Receptacles. Receptacles incorporating an isolated grounding conductor connection intended for the reduction of electrical noise (electromagnetic interference) as permitted in 250.146(D) shall be identified by an orange trian‐ gle located on the face of the receptacle.
      1. Isolated Equipment Grounding Conductor Required. Receptacles so identified shall be used only with equipment grounding conductors that are isolated in accordance with 250.146(D).
      2. Installation in Nonmetallic Boxes. Isolated ground recep‐ tacles installed in nonmetallic boxes shall be covered with a nonmetallic faceplate.Exception: Where an isolated ground receptacle is installed in a nonme‐ tallic box, a metal faceplate shall be permitted if the box contains a feature or accessory that permits the effective grounding of the faceplate.
    5. Controlled Receptacle Marking. All nonlocking-type, 125-volt, 15- and 20-ampere receptacles that are controlled by an automatic control device, or that incorporate control features that remove power from the receptacle for the purpose of energy management or building automation, shall be permanently marked with the symbol shown in Figure 406.3(E) and the word “controlled.”Exception: The marking shall not be required for receptacles controlled by a wall switch that provide the required room lighting outlets as permitted by 210.70.
    6. Receptacle with USB Charger. A 125-volt 15- or 20-ampere receptacle that additionally provides Class 2 power shall be listed and constructed such that the Class 2 circuitry is integral with the receptacle.
  4. General Installation Requirements. Receptacle outlets shall be located in branch circuits in accordance with Part III of Article 210. General installation requirements shall be in accordance with 406.4(A) through (F).
    1. Grounding Type. Except as provided in 406.4(D), recep‐ tacles installed on 15- and 20-ampere branch circuits shall be of the grounding type. Grounding-type receptacles shall be instal‐ led only on circuits of the voltage class and current for which they are rated, except as provided in Table 210.21(B)(2) and Table 210.21(B)(3).
    2. To Be Grounded. Receptacles and cord connectors that have equipment grounding conductor contacts shall have those contacts connected to an equipment grounding conductor.Exception No. 1: Receptacles mounted on portable and vehicle-mounted generator sets and generators in accordance with 250.34.Exception No. 2: Replacement receptacles as permitted by 406.4(D).
    3. Methods of Grounding. The equipment grounding conductor contacts of receptacles and cord connectors shall be grounded by connection to the equipment grounding conduc‐ tor of the circuit supplying the receptacle or cord connector.Informational Note: For installation requirements for the reduc‐ tion of electrical noise, see 250.146(D).The branch-circuit wiring method shall include or provide an equipment grounding conductor to which the equipment grounding conductor contacts of the receptacle or cord connector are connected.Informational Note No. 1: See 250.118 for acceptable grounding means.Informational Note No. 2: For extensions of existing branch circuits, see 250.130.
    4. Replacements. Replacement of receptacles shall comply with 406.4(D)(1) through (D)(6), as applicable. Arc-fault circuit-interrupter type and ground-fault circuit-interrupter type receptacles shall be installed in a readily accessible loca‐ tion.

      FIGURE 406.3(E) Controlled Receptacle Marking Symbol.
      1. Grounding-Type Receptacles. Where a grounding means exists in the receptacle enclosure or an equipment grounding conductor is installed in accordance with 250.130(C), grounding-type receptacles shall be used and shall be connec‐ ted to the equipment grounding conductor in accordance with 406.4(C) or 250.130(C).
      2. Non–Grounding-Type Receptacles. Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(2)(a), (D)(2)(b), or (D)(2)(c).
        1. A non–grounding-type receptacle(s) shall be permit‐ ted to be replaced with another non–grounding-type recepta‐ cle(s).
        2. A non–grounding-type receptacle(s) shall be permit‐ ted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles or their cover plates shall be marked “No Equipment Ground.” An equipment grounding conductor shall not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle.
        3. A non–grounding-type receptacle(s) shall be permit‐ ted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Where grounding-type receptacles are supplied through the ground- fault circuit interrupter, grounding-type receptacles or their cover plates shall be marked “GFCI Protected” and “No Equip‐ ment Ground,” visible after installation. An equipment ground‐ ing conductor shall not be connected between the grounding- type receptacles.
          Informational Note No. 1: Some equipment or appliance manu‐facturers require that the branch circuit to the equipment or appliance includes an equipment grounding conductor.
          Informational Note No. 2: See 250.114 for a list of a cord-and-plug-connected equipment or appliances that require an equip‐ ment grounding conductor.
      3. Ground-Fault Circuit Interrupters. Ground-fault circuit- interrupter protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so protected elsewhere in this Code.Exception: Where replacement of the receptacle type is impracticable, such as where the outlet box size will not permit the installation of the GFCI receptacle, the receptacle shall be permitted to be replaced with a new receptacle of the existing type, where GFCI protection is provided and the receptacle is marked “GFCI Protected” and “No Equipment Ground,” in accordance with 406.4(D)(2)(a), (b), or (c), as applicable.
      4. Arc-Fault Circuit-Interrupter Protection. Where a recepta‐ cle outlet is located in any areas specified in 210.12(A) or (B), a replacement receptacle at this outlet shall be one of the following:
        1. A listed outlet branch-circuit type arc-fault circuit- interrupter receptacle
        2. A receptacle protected by a listed outlet branch-circuit type arc-fault circuit-interrupter type receptacle
        3. A receptacle protected by a listed combination type arc- fault circuit-interrupter type circuit breaker
        Exception No. 1: Arc-fault circuit-interrupter protection shall not berequired where all of the following apply:
        1. The replacement complies with 406.4(D)(2)(b).
        2. It is impracticable to provide an equipment grounding conductor as provided by 250.130(C).
        1. A listed combination type arc-fault circuit-interrupter circuitbreaker is not commercially available.
        2. GFCI/AFCI dual function receptacles are not commercially avail‐ able.

        Exception No. 2: Section 210.12(B), Exception shall not apply toreplacement of receptacles.
      5. Tamper-Resistant Receptacles. Listed tamper-resistant receptacles shall be provided where replacements are made at receptacle outlets that are required to be tamper-resistant else‐ where in this Code, except where a non-grounding receptacle is replaced with another non-grounding receptacle.
      6. Weather-Resistant Receptacles. Weather-resistant recepta‐ cles shall be provided where replacements are made at recepta‐ cle outlets that are required to be so protected elsewhere in this Code.
    5. Cord- and Plug-Connected Equipment. The installation of grounding-type receptacles shall not be used as a requirement that all cord-and plug-connected equipment be of the groun‐ ded type.Informational Note: See 250.114 for types of cord-and plug- connected equipment to be grounded.
    6. Noninterchangeable Types. Receptacles connected to circuits that have different voltages, frequencies, or types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used on these circuits are not inter‐ changeable.
  5. Receptacle Mounting. Receptacles shall be mounted in identified boxes or assemblies. The boxes or assemblies shall be securely fastened in place unless otherwise permitted elsewhere in this Code. Screws used for the purpose of attaching recepta‐ cles to a box shall be of the type provided with a listed recepta‐ cle, or shall be machine screws having 32 threads per inch or part of listed assemblies or systems, in accordance with the manufacturer’s instructions.
  1. Boxes That Are Set Back. Receptacles mounted in boxes that are set back from the finished surface as permitted in314.20 shall be installed such that the mounting yoke or strap of the receptacle is held rigidly at the finished surface.
  2. Boxes That Are Flush. Receptacles mounted in boxes that are flush with the finished surface or project therefrom shall be installed such that the mounting yoke or strap of the receptacle is held rigidly against the box or box cover.
  3. Receptacles Mounted on Covers. Receptacles mounted to and supported by a cover shall be held rigidly against the cover by more than one screw or shall be a device assembly or box cover listed and identified for securing by a single screw.
  4. Position of Receptacle Faces. After installation, recepta‐ cle faces shall be flush with or project from faceplates of insu‐ lating material and shall project a minimum of 0.4 mm (0.015 in.) from metal faceplates.Exception: Listed kits or assemblies encompassing receptacles and nonmetallic faceplates that cover the receptacle face, where the plate cannot be installed on any other receptacle, shall be permitted.
  5. Receptacles in Countertops. Receptacle assemblies for installation in countertop surfaces shall be listed for counter‐ top applications. Where receptacle assemblies for countertop applications are required to provide ground-fault circuit-
    interrupter protection for personnel in accordance with 210.8, such assemblies shall be permitted to be listed as GFCI recepta‐ cle assemblies for countertop applications.imageN
  6. Receptacles in Work Surfaces. Receptacle assemblies and GFCI receptacle assemblies listed for work surface or counter‐ top applications shall be permitted to be installed in work surfaces.imageN
  7. Receptacle Orientation. Receptacles shall not be installed in a face-up position in or on countertop surfaces or work surfaces unless listed for countertop or work surface applica‐ tions.
  8. Receptacles in Seating Areas and Other Similar Surfaces. In seating areas or similar surfaces, receptacles shall not be installed in a face-up position unless the receptacle is any of the following:
  1. Part of an assembly listed as a furniture power distribu‐ tion unit
  2. Part of an assembly listed either as household furnishings or as commercial furnishings
  3. Listed either as a receptacle assembly for countertop applications or as a GFCI receptacle assembly for counter‐ top applications
  4. Installed in a listed floor box
  1. Exposed Terminals. Receptacles shall be enclosed so that live wiring terminals are not exposed to contact.
  2. Voltage Between Adjacent Devices. A receptacle shall not be grouped or ganged in enclosures with other receptacles, snap switches, or similar devices, unless they are arranged so that the voltage between adjacent devices does not exceed 300 volts, or unless they are installed in enclosures equipped with identified, securely installed barriers between adjacent devices.

406.6 Receptacle Faceplates (Cover Plates). Receptacle face‐ plates shall be installed so as to completely cover the opening and seat against the mounting surface.

Receptacle faceplates mounted inside a box having a recess- mounted receptacle shall effectively close the opening and seat against the mounting surface.

  1. Thickness of Metal Faceplates. Metal faceplates shall be of ferrous metal not less than 0.76 mm (0.030 in.) in thickness or of nonferrous metal not less than 1.02 mm (0.040 in.) in thickness.
  2. Grounding. Metal faceplates shall be grounded.
  3. Faceplates of Insulating Material. Faceplates of insulating material shall be noncombustible and not less than 2.54 mm (0.10 in.) in thickness but shall be permitted to be less than2.54 mm (0.10 in.) in thickness if formed or reinforced to provide adequate mechanical strength.imageN
  4. Receptacle Faceplate (Cover Plates) with Integral Night Light and/or USB Charger. A flush device cover plate that additionally provides a night light and/or Class 2 output connector(s) shall be listed and constructed such that the night light and/or Class 2 circuitry is integral with the flush device cover plate.
  1. Attachment Plugs, Cord Connectors, and Flanged Surface Devices. All attachment plugs, cord connectors, and flanged surface devices (inlets and outlets) shall be listed andmarked with the manufacturer’s name or identification and voltage and ampere ratings.
    1. Construction of Attachment Plugs and Cord Connectors. Attachment plugs and cord connectors shall be constructed so that there are no exposed current-carrying parts except the prongs, blades, or pins. The cover for wire terminations shall be a part that is essential for the operation of an attachment plug or connector (dead-front construction).
    2. Connection of Attachment Plugs. Attachment plugs shall be installed so that their prongs, blades, or pins are not ener‐ gized unless inserted into an energized receptacle or cord connectors. No receptacle shall be installed so as to require the insertion of an energized attachment plug as its source of supply.
    3. Attachment Plug Ejector Mechanisms. Attachment plug ejector mechanisms shall not adversely affect engagement of the blades of the attachment plug with the contacts of the receptacle.
    4. Flanged Surface Inlet. A flanged surface inlet shall be installed such that the prongs, blades, or pins are not energized unless an energized cord connector is inserted into it.
  2. Noninterchangeability. Receptacles, cord connectors, and attachment plugs shall be constructed such that receptacle or cord connectors do not accept an attachment plug with a different voltage or current rating from that for which the device is intended. However, a 20-ampere T-slot receptacle or cord connector shall be permitted to accept a 15-ampere attachment plug of the same voltage rating. Non–grounding- type receptacles and connectors shall not accept grounding- type attachment plugs.
  3. Receptacles in Damp or Wet Locations.
    1. Damp Locations. A receptacle installed outdoors in a location protected from the weather or in other damp loca‐ tions shall have an enclosure for the receptacle that is weather‐ proof when the receptacle is covered (attachment plug cap not inserted and receptacle covers closed).An installation suitable for wet locations shall also be consid‐ ered suitable for damp locations.A receptacle shall be considered to be in a location protec‐ ted from the weather where located under roofed open porches, canopies, marquees, and the like, and will not be subjected to a beating rain or water runoff. All 15- and 20-ampere, 125- and 250-volt nonlocking receptacles shall be a listed weather-resistant type.Informational Note: The types of receptacles covered by this requirement are identified as 5-15, 5-20, 6-15, and 6-20 in ANSI/ NEMA WD 6–2012, Wiring Devices — Dimensional Specifications.
    2. Wet Locations.
      1. Receptacles of 15 and 20 Amperes in a Wet Location. Receptacles of 15 and 20 amperes, 125 and 250 volts installed in a wet location shall have an enclosure that is weatherproof whether or not the attachment plug cap is inserted. An outlet box hood installed for this purpose shall be listed and shall be identified as “extra-duty.” Other listed products, enclosures, or assemblies providing weatherproof protection that do not utilize an outlet box hood need not be marked “extra duty.”
        imageException: 15- and 20-ampere, 125- through 250-volt receptacles instal‐led in a wet location and subject to routine high-pressure spray washing shall be permitted to have an enclosure that is weatherproof when the attachment plug is removed.Informational Note No. 1: Requirements for extra-duty outlet box hoods are found in ANSI/UL 514D–2013, Cover Plates for Flush-Mounted Wiring Devices. “Extra duty” identification and requirements are not applicable to listed receptacles, faceplates, outlet boxes, enclosures, or assemblies that are identified as either being suitable for wet locations or rated as one of the outdoor enclosure–type numbers of Table 110.28 that does not utilize an outlet box hood.
        All 15- and 20-ampere, 125- and 250-volt nonlocking-type receptacles shall be listed and so identified as the weather- resistant type.Informational Note No. 2: The configuration of weather- resistant receptacles covered by this requirement are identified as 5-15, 5-20, 6-15, and 6-20 in ANSI/NEMA WD 6–2012, WiringDevices — Dimensional Specifications.•
      2. Other Receptacles. All other receptacles installed in a wetlocation shall comply with (B)(2)(a) or (B)(2)(b).
        1. A receptacle installed in a wet location, where the product intended to be plugged into it is not attended while in use, shall have an enclosure that is weatherproof with the attachment plug cap inserted or removed.
        2. A receptacle installed in a wet location where the product intended to be plugged into it will be attended while in use (e.g., portable tools) shall have an enclosure that is weatherproof when the attachment plug is removed.
    3. Bathtub and Shower Space. Receptacles shall not be installed within or directly over a bathtub or shower stall.
    4. Protection for Floor Receptacles. Standpipes of floor receptacles shall allow floor-cleaning equipment to be operated without damage to receptacles.
    5. Flush Mounting with Faceplate. The enclosure for a receptacle installed in an outlet box flush-mounted in a finished surface shall be made weatherproof by means of a weatherproof faceplate assembly that provides a watertight connection between the plate and the finished surface.
  4. Grounding-Type Receptacles, Adapters, Cord Connec‐ tors, and Attachment Plugs.
    1. Grounding Poles. Grounding-type receptacles, cord connectors, and attachment plugs shall be provided with one fixed grounding pole in addition to the circuit poles. The grounding contacting pole of grounding-type plug-in ground- fault circuit interrupters shall be permitted to be of the mova‐ ble, self-restoring type on circuits operating at not over 150 volts between any two conductors or any conductor and ground.
    2. Grounding-Pole Identification. Grounding-type recepta‐ cles, adapters, cord connections, and attachment plugs shall have a means for connection of an equipment grounding conductor to the grounding pole.A terminal for connection to the grounding pole shall be designated by one of the following:
      1. A green-colored hexagonal-headed or -shaped terminal screw or nut, not readily removable.
      2. A green-colored pressure wire connector body (a wire barrel).
      3. A similar green-colored connection device, in the case of adapters. The grounding terminal of a grounding adapter shall be a green-colored rigid ear, lug, or similar device. The equipment grounding connection shall be so designed that it cannot make contact with current- carrying parts of the receptacle, adapter, or attachment plug. The adapter shall be polarized.
      4. If the terminal for the equipment grounding conductor is not visible, the conductor entrance hole shall be marked with the word green or ground, the letters or GR, a grounding symbol, or otherwise identified by a distinctive green color. If the terminal for the equipment grounding conductor is readily removable, the area adjacent to the terminal shall be similarly marked.
      Informational Note: See Informational Note Figure 406.10(B)(4).
    3. Grounding Terminal Use. A grounding terminal shall not be used for purposes other than grounding.
    4. Grounding-Pole Requirements. Grounding-type attach‐ ment plugs and mating cord connectors and receptacles shall be designed such that the equipment grounding connection is made before the current-carrying connections. Grounding-type devices shall be so designed that grounding poles of attach‐ ment plugs cannot be brought into contact with current- carrying parts of receptacles or cord connectors.
    5. Use. Grounding-type attachment plugs shall be used only with a cord having an equipment grounding conductor.
    Informational Note: See 250.126 for identification of grounding conductor terminals.
  5. Connecting Receptacle Grounding Terminal to Box. The connection of the receptacle grounding terminal shall comply with 250.146.
  6. Tamper-Resistant Receptacles. All 15- and 20-ampere, 125- and 250-volt nonlocking-type receptacles in the areas specified in 406.12(1) through (7) shall be listed tamper- resistant receptacles.

(1) Dwelling units in all areas specified in 210.52 and 550.13

  1. Guest rooms and guest suites of hotels and motels
  2. Child care facilities
  3. Preschools and elementary education facilities
  4. Business offices, corridors, waiting rooms and the like in clinics, medical and dental offices and outpatient facilities
  5. Subset of assembly occupancies described in 518.2 to include places of waiting transportation, gymnasiums, skating rinks, and auditoriums
  6. Dormitories

Informational Note: This requirement would include recepta‐

cles identified as 5-15, 5-20, 6-15, and 6-20 in ANSI/NEMA WD 6-2016, Wiring Devices — Dimensional Specifications.

Exception to (1), (2), (3), (4), (5), (6), and (7): Receptacles in the following locations shall not be required to be tamper resistant:

  1. Receptacles located more than 1.7 m (5 12 ft) above the floor
    imageInformational Note Figure 406.10(B)(4) One Example of a Symbol Used to Identify the Termination Point for an Equipment Grounding Conductor.
  2. Receptacles that are part of a luminaire or appliance
  3. A single receptacle or a duplex receptacle for two appliances loca‐ ted within the dedicated space for each appliance that, in normal use, is not easily moved from one place to another and that is cord-and-plug-connected in accordance with 400.10(A)(6), (A)(7), or (A)(8)
  4. Nongrounding receptacles used for replacements as permitted in 406.4(D)(2)(a)