ZaneMeyers/zmVault
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

vault backup: 2025-12-10 15:58:11

Browse Source
This commit is contained in:
Zane Meyers
2025-12-10 15:58:11 -05:00
parent 2a36747bee
commit 8cb39aad0e
150 changed files with 1530 additions and 868 deletions
Download Patch File Download Diff File Expand all files Collapse all files
nfpa-70_dump_wiring-methods.md
+1 -391
View File
@@ -7,7 +7,7 @@ tags:
- exclude-from-word-count
- status/incomplete
- topic/construction/electrical
- type/media
- type/media/reference
title: Article 725 Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits
---
# NEC Chapter 3 Wiring Methods Articles Dump
@@ -827,137 +827,6 @@ Armor shall be permitted over the jacket. If provided, the armor or metallic cov
Type P cable shall be marked in accordance with 310.8. When an armor is provided, the cable shall be marked accordingly.
# 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 230.6,
230.7, and Parts II, III, and IV of 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 Part II of Article 334, excluding 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 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.
# Article 340 Underground Feeder and Branch-Circuit Cable: Type UF
@@ -1765,265 +1634,6 @@ Where required or installed, equipment bonding jumpers shall be installed in acc
LFMC shall be marked according to 110.21. The trade size and other information required by the listing shall also be marked on the conduit. Conduit suitable for direct burial shall be so marked.
# Article 352 Rigid Polyvinyl Chloride Conduit: Type PVC
## Part I. General
### 352.1 Scope.
This article covers the use, installation, and construction specifications for rigid polyvinyl chloride conduit (PVC) and associated fittings.
> [!info] Informational Note:
> Refer to Article 353 for High Density Polyethylene Conduit: Type HDPE, and Article 355 for Reinforced
Thermosetting Resin Conduit: Type RTRC.
### 352.2 Definition.
The definition in this section shall apply within this article and throughout the Code.
Rigid Polyvinyl Chloride Conduit (PVC).
A rigid nonmetallic raceway of circular cross section, with integral or associated couplings, connectors, and fittings for the installation of electrical conductors and cables.
### 352.6 Listing Requirements.
PVC conduit, factory elbows, and associated fittings shall be listed.
## Part II. Installation
### 352.10 Uses Permitted.
The use of PVC conduit shall be permitted in accordance with 352.10(A) through (I).
> [!info] Informational Note:
> Extreme cold may cause some nonmetallic conduits to become brittle and, therefore, more susceptible to damage from physical contact.
#### 352.10(A) Concealed.
PVC conduit shall be permitted in walls, floors, and ceilings.
#### 352.10(B) Corrosive Influences.
PVC conduit shall be permitted in locations subject to severe corrosive influences as covered in 300.6 and where subject to chemicals for which the materials are specifically approved.
#### 352.10(C) Cinders.
PVC conduit shall be permitted in cinder fill.
#### 352.10(D) Wet Locations.
PVC conduit shall be permitted in portions of dairies, laundries, canneries, or other wet locations, and in locations where walls are frequently washed, the entire conduit system, including boxes and fittings used therewith, shall be installed and equipped so as to prevent water from entering the conduit. All supports, bolts, straps, screws, and so forth, shall be of corrosion-resistant materials or be protected against corrosion by approved corrosion-resistant materials.
#### 352.10(E) Dry and Damp Locations.
PVC conduit shall be permitted for use in dry and damp locations not prohibited by 352.12.
#### 352.10(F) Exposed.
PVC conduit shall be permitted for exposed work. PVC conduit used exposed in areas of physical damage shall be identified for the use.
> [!info] Informational Note:
> PVC Conduit, Type Schedule 80, is identified for areas of physical damage.
#### 352.10(G) Underground Installations.
For underground installations, PVC shall be permitted for direct burial and underground encased in concrete. See 300.5 and 300.50.
#### 352.10(H) Support of Conduit Bodies.
PVC conduit shall be permitted to support nonmetallic conduit bodies not larger than the largest trade size of an entering raceway.
These conduit bodies shall not support luminaires or other equipment and shall not contain devices other than splicing devices as permitted by 110.14(B) and 314.16(C)(2).
#### 352.10(I) Insulation Temperature Limitations.
Conductors or cables rated at a temperature higher than the listed temperature rating of PVC conduit shall be permitted to be installed in PVC conduit, provided the conductors or cables are not operated at a temperature higher than the listed temperature rating of the
PVC conduit.
### 352.12 Uses Not Permitted.
PVC conduit shall not be used under the conditions specified in 352.12(A) through (E).
#### 352.12(A) Hazardous (Classified) Locations.
In any hazardous (classified) location, except as permitted by other articles of this Code.
#### 352.12(B) Support of Luminaires.
For the support of luminaires or other equipment not described in 352.10(H).
#### 352.12(C) Physical Damage.
Where subject to physical damage unless identified for such use.
#### 352.12(D) Ambient Temperatures.
Where subject to ambient temperatures in excess of 50°C (122°F) unless listed otherwise.
#### 352.12(E) Theaters and Similar Locations.
In theaters and similar locations, except as provided in 518.4 and 520.5.
### 352.20 Size.
#### 352.20(A) Minimum.
PVC conduit smaller than metric designator 16 (trade size 1⁄2) shall not be used.
#### 352.20(B) Maximum.
PVC conduit larger than metric designator 155 (trade size 6) shall not be used.
> [!info] Informational Note:
> The trade sizes and metric designators are for identification purposes only and do not relate to actual dimensions.
See 300.1(C).
### 352.22 Number of Conductors.
The number of conductors shall not exceed that permitted by the percentage fill specified in Table 1, Chapter 9.
Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles. The number of cables shall not exceed the allowable percentage fill specified in Table 1, Chapter 9.
### 352.24 Bends — How Made.
Bends shall be so made that the conduit will not be damaged and the internal diameter of the conduit will not be effectively reduced.
Field bends shall be made only with identified bending equipment. The radius of the curve to the centerline of such bends shall not be less than shown in Table 2, Chapter 9.
### 352.26 Bends — Number in One Run.
There shall not be more than the equivalent of four quarter bends (360 degrees total) between pull points, for example, conduit bodies and boxes.
### 352.28 Trimming.
All cut ends shall be trimmed inside and outside to remove rough edges.
### 352.30 Securing and Supporting.
PVC conduit shall be installed as a complete system as provided in 300.18 and shall be fastened so that movement from thermal expansion or contraction is permitted. PVC conduit shall be securely fastened and supported in accordance with 352.30(A) and (B).
#### 352.30(A) Securely Fastened.
PVC conduit shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, conduit body, or other conduit termination. Conduit listed for securing at other than 900 mm (3 ft) shall be permitted to be installed in accordance with the listing.
#### 352.30(B) Supports.
PVC conduit shall be supported as required in Table 352.30. Conduit listed for support at spacings other than as shown in Table 352.30 shall be permitted to be installed in accordance with the listing. Horizontal runs of PVC conduit supported by openings through framing members at intervals not exceeding those in Table 352.30 and securely fastened within 900 mm (3 ft) of termination points shall be permitted.
Table 352.30 Support of Rigid Polyvinyl Chloride Conduit (PVC)
Conduit Size Maximum Spacing Between Supports
Metric Designator Trade Size mm or m ft
16–27 1⁄2–1 900 mm 3
35–53 11⁄4–2 1.5 m 5
63–78 21⁄2–3 1.8 m 6
91–129 31⁄2–5 2.1 m 7
Conduit Size Maximum Spacing Between Supports
Metric Designator Trade Size mm or m ft
155 6 2.5 m 8
### 352.44 Expansion Fittings.
Expansion fittings for PVC conduit shall be provided to compensate for thermal expansion and contraction where the length change, in accordance with Table 352.44, is expected to be 6 mm (1⁄4 in.) or greater in a straight run between securely mounted items such as boxes, cabinets, elbows, or other conduit terminations.
Table 352.44 Expansion Characteristics of PVC Rigid Nonmetallic Conduit Coefficient of Thermal
Expansion = 6.084 × 10 mm/mm/°C (3.38 × 10 in./in./°F)
Temperature
Change (°C)
Length Change of
PVC Conduit
(mm/m)
Temperature
Change (°F)
Length Change of
PVC Conduit
(in./100 ft)
Temperature
Change (°F)
Length Change of
PVC Conduit
(in./100 ft)
5 0.30 5 0.20 105 4.26
10 0.61 10 0.41 110 4.46
15 0.91 15 0.61 115 4.66
20 1.22 20 0.81 120 4.87
25 1.52 25 1.01 125 5.07
30 1.83 30 1.22 130 5.27
35 2.13 35 1.42 135 5.48
40 2.43 40 1.62 140 5.68
45 2.74 45 1.83 145 5.88
50 3.04 50 2.03 150 6.08
55 3.35 55 2.23 155 6.29
60 3.65 60 2.43 160 6.49
65 3.95 65 2.64 165 6.69
70 4.26 70 2.84 170 6.90
75 4.56 75 3.04 175 7.10
80 4.87 80 3.24 180 7.30
85 5.17 85 3.45 185 7.50
90 5.48 90 3.65 190 7.71
95 5.78 95 3.85 195 7.91
100 6.08 100 4.06 200 8.11
### 352.46 Bushings.
Where a conduit enters a box, fitting, or other enclosure, a bushing or adapter shall be provided to protect the wire from abrasion unless the box, fitting, or enclosure design provides equivalent protection.
> [!info] Informational Note:
> See 300.4(G) for the protection of conductors 4 AWG and larger at bushings.
### 352.48 Joints.
All joints between lengths of conduit, and between conduit and couplings, fittings, and boxes, shall be made by an approved method.
### 352.56 Splices and Taps.
Splices and taps shall be made in accordance with 300.15.
### 352.60 Grounding.
Where equipment grounding is required, a separate equipment grounding conductor shall be installed in the conduit.
–5 –5
> [!important] Exception No. 1:
> As permitted in 250.134, Exception No. 2, for dc circuits and 250.134, Exception No. 1, for separately run equipment grounding conductors.
> [!important] Exception No. 2:
> Where the grounded conductor is used to ground equipment as permitted in 250.142.
## Part III. Construction Specifications
### 352.100 Construction.
PVC conduit shall be made of rigid (nonplasticized) polyvinyl chloride (PVC). PVC conduit and fittings shall be composed of suitable nonmetallic material that is resistant to moisture and chemical atmospheres. For use aboveground, it shall also be flame retardant, resistant to impact and crushing, resistant to distortion from heat under conditions likely to be encountered in service, and resistant to low temperature and sunlight effects. For use underground, the material shall be acceptably resistant to moisture and corrosive agents and shall be of sufficient strength to withstand abuse, such as by impact and crushing, in handling and during installation. Where intended for direct burial, without encasement in concrete, the material shall also be capable of withstanding continued loading that is likely to be encountered after installation.
### 352.120 Marking.
Each length of PVC conduit shall be clearly and durably marked at least every 3 m (10 ft) as required in the first sentence of 110.21(A).
The type of material shall also be included in the marking unless it is visually identifiable. For conduit recognized for use aboveground, these markings shall be permanent. For conduit limited to underground use only, these markings shall be sufficiently durable to remain legible until the material is installed. Conduit shall be permitted to be surface marked to indicate special characteristics of the material.
> [!info] Informational Note:
> Examples of these markings include but are not limited to “limited smoke” and “sunlight resistant.”
# Article 353 High Density Polyethylene Conduit: Type HDPE Conduit
## Part I. General