---
aliases:
  - nec-338
title: "Article 338 Service-Entrance Cable: Types SE and USE"
tags:
  - authorship/other
  - exclude-from-word-count
  - status/draft
  - topic/construction/electrical
  - type/media/reference
---
# Article 338 Service-Entrance Cable: Types SE and USE

## Part I. General

### 338.1 Scope.

This article covers the use, installation, and construction specifications of service-entrance cable.

### 338.2 Definitions.

The definition in this section shall apply within this article and throughout the Code.

#### Service-Entrance Cable.

A single conductor or multiconductor cable provided with an overall covering, primarily used for services, and of the following types:

#### Type SE.

Service-entrance cable having a flame-retardant, moisture-resistant covering.

#### Type USE.

Service-entrance cable, identified for underground use, having a moisture-resistant covering, but not required to have a flame-retardant covering.

#### Service-Entrance Conductor Assembly.

Multiple single-insulated conductors twisted together without an overall covering, other than an optional binder intended only to keep the conductors together.

### 338.6 Listing Requirements.

Type SE and USE cables and associated fittings shall be listed.

## Part II. Installation

### 338.10 Uses Permitted.

#### 338.10(A) Service-Entrance Conductors.

Service-entrance cable shall be permitted to be used as service-entrance conductors and shall be installed in accordance with [[nfpa-70_230_services#230.6 Conductors Considered Outside the Building.|230.6]],
[[nfpa-70_230_services#230.7 Other Conductors in Raceway or Cable.|230.7]],
and Parts [[nfpa-70_230_services#Part II. Overhead Service Conductors|II]],
[[nfpa-70_230_services#Part III. Underground Service Conductors|III]],
and [[nfpa-70_230_services#Part IV. Service-Entrance Conductors|IV]],
of [[nfpa-70_230_services#Article 230 Services|Article 230]].

#### 338.10(B) Branch Circuits or Feeders.

##### 338.10(B)(1) Grounded Conductor Insulated.

Type SE service-entrance cables shall be permitted
in wiring systems where all of the circuit conductors of the cable
are of the thermoset or thermoplastic type.

##### 338.10(B)(2) Use of Uninsulated Conductor.

Type SE service-entrance cable shall be permitted for use where the insulated conductors are used for circuit wiring and the uninsulated conductor is used only for equipment grounding purposes.

> [!important] Exception:
> In existing installations,
> uninsulated conductors shall be permitted as a grounded conductor
> in accordance with 250.32
> and 250.140,
> where the uninsulated grounded conductor of the cable
> originates in service equipment,
> and with 225.30
> through 225.40.

##### 338.10(B)(3) Temperature Limitations.

Type SE service-entrance cable used to supply appliances
shall not be subject to conductor temperatures
in excess of the temperature specified for the type of insulation involved.

##### 338.10(B)(4) Installation Methods for Branch Circuits and Feeders.

> [!info] Informational Note No. 1:
> See 310.14(A)(3) for temperature limitation of conductors.

> [!info] Informational Note No. 2:
> For the installation of main power feeder conductors in dwelling units refer to 310.12.

* (a) Interior Installations.

    * (1) In addition to the provisions of this article,
        Type SE service-entrance cable used for interior wiring
        shall comply with the installation requirements
        of [[nfpa-70_334_nm-cable#Part II. Installation|Part II of Article 334]],
        excluding [[nfpa-70_334_nm-cable#334.80 Ampacity.|334.80]].

    * (2) Where more than two Type SE cables
        containing two or more current-carrying conductors in each cable
        are installed in contact with thermal insulation, caulk, or sealing foam
        without maintaining spacing between cables,
        the ampacity of each conductor shall be adjusted
        in accordance with [[nfpa-70_310_conductors_for_general_wiring#Table 310.15(C)(1) Adjustment Factors for More Than Three Current-Carrying Conductors|Table 310.15(C)(1)]].

    * (3) For Type SE cable with ungrounded conductor sizes 10 AWG and smaller,
        where installed in contact with thermal insulation,
        the ampacity shall be in accordance with 60°C (140°F) conductor temperature rating.
        The maximum conductor temperature rating
        shall be permitted to be used for ampacity adjustment and correction purposes,
        if the final ampacity does not exceed that for a 60°C (140°F) rated conductor.

* (b) Exterior Installations.

    * (1) In addition to the provisions of this article,
        service-entrance cable used for feeders or branch circuits,
        where installed as exterior wiring,
        shall be installed in accordance with Part I of Article 225.
        The cable shall be supported in accordance with 334.30.

    * (2) Type USE cable installed as underground feeder and branch circuit cable
        shall comply with Part II of Article 340.

        > [!important] Exception:
        > Single-conductor Type USE and multi-rated USE conductors
        > shall not be subject to the ampacity limitations
        > of Part II of Article 340.

### 338.12 Uses Not Permitted.

#### 338.12(A) Service-Entrance Cable.

Service-entrance cable (SE) shall not be used under the following conditions or in the following locations:

* (1) Where subject to physical damage
    unless protected in accordance with 230.50(B)

* (2) Underground with or without a raceway

* (3) For exterior branch circuits and feeder wiring
    unless the installation complies with the provisions of Part I of Article 225
    and is supported in accordance with 334.30
    or is used as messenger-supported wiring
    as permitted in Part II of Article 396

#### 338.12(B) Underground Service-Entrance Cable.

Underground service-entrance cable (USE)
shall not be used under the following conditions or in the following locations:

* (1) For interior wiring

* (2) For aboveground installations
    except where USE cable emerges from the ground
    and is terminated in an enclosure at an outdoor location
    and the cable is protected in accordance with 300.5(D)

* (3) As aerial cable
    unless it is a multiconductor cable identified for use aboveground
    and installed as messenger-supported wiring
    in accordance with 225.10
    and Part II of Article 396

### 338.24 Bending Radius.

Bends in Types USE and SE cable shall be so made that the cable will not be damaged. The radius of the curve of the inner edge of any bend, during or after installation, shall not be less than five times the diameter of the cable.

## Part III. Construction Specifications

### 338.100 Construction.

#### 338.100(A) Assemblies.

Cabled assemblies of multiple single-conductor Type USE conductors
shall be permitted for direct burial.
All conductors shall be insulated.

> [!info] Informational Note:
> The term "cabled" refers to a manufacturing process
> of twisting single conductors together
> and may also be referred to as "plexed."

#### 338.100(B) Uninsulated Conductor.

Type SE or USE cable with an overall covering containing two or more conductors
shall be permitted to have one conductor uninsulated.

### 338.120 Marking.

Service-entrance cable shall be marked
as required in 310.8.
Cable with the neutral conductor smaller than the ungrounded conductors
shall be so marked.
