107 lines
4.2 KiB
Markdown
107 lines
4.2 KiB
Markdown
---
|
|
id:
|
|
aliases:
|
|
- nec-310
|
|
tags:
|
|
- authorship/other
|
|
- destiny/uncertain
|
|
- exclude-from-word-count
|
|
- status/incomplete
|
|
- topic/construction/electrical
|
|
- type/media
|
|
title: Article 300 General Requirements for Wiring Methods and Materials
|
|
---
|
|
# Article 300 General Requirements for Wiring Methods and Materials
|
|
|
|
## Part I. General Requirements
|
|
|
|
### 300.1 Scope.
|
|
|
|
#### 300.1(A) All Wiring Installations.
|
|
|
|
This article covers general requirements for wiring methods and materials for all wiring installations unless modified by other articles in Chapter 3.
|
|
|
|
#### 300.1(B) Integral Parts of Equipment.
|
|
|
|
The provisions of this article are not intended to apply to the conductors that form an integral part of equipment, such as motors, controllers, motor control centers, or factory-assembled control equipment or listed utilization equipment.
|
|
|
|
#### 300.1(C) Metric Designators and Trade Sizes.
|
|
|
|
Metric designators and trade sizes for conduit, tubing, and associated fittings and accessories shall be as designated in Table 300.1(C).
|
|
|
|
#### Table 300.1(C) Metric Designators and Trade Sizes
|
|
|
|
| Metric Designator | Trade Size |
|
|
| -----------------:| ----------:|
|
|
| 12 | 3/8 |
|
|
| 16 | 1/2 |
|
|
| 21 | 3/4 |
|
|
| 27 | 1 |
|
|
| 35 | 1-1/4 |
|
|
| 41 | 1-1/2 |
|
|
| 53 | 2 |
|
|
| 63 | 2-1/2 |
|
|
| 78 | 3 |
|
|
| 91 | 3-1/2 |
|
|
| 103 | 4 |
|
|
| 129 | 5 |
|
|
| 155 | 6 |
|
|
|
|
<!-- TODO: TEXT OMITTED -->
|
|
|
|
### 300.19 Supporting Conductors in Vertical Raceways.
|
|
|
|
#### 300.19(A) Spacing Intervals -- Maximum.
|
|
|
|
Conductors in vertical [[nfpa-70_100_definitions#Raceway.|raceways]] shall be supported
|
|
if the vertical rise exceeds the values in Table 300.19(A).
|
|
At least one support method shall be provided for each conductor
|
|
at the top of the vertical raceway or as close to the top as practical.
|
|
Intermediate supports shall be provided
|
|
as necessary to limit supported conductor lengths
|
|
to not greater than those values specified in Table 300.19(A).
|
|
|
|
#### Table 300.19(A) Spacings for Conductor Supports
|
|
|
|
| Conductor Size | Aluminum or Copper-Clad Aluminum | Copper |
|
|
| -------------------------------- | --------------------------------:| ------:|
|
|
| 18 AWG through 8 AWG | 100ft | 100ft |
|
|
| 6 AWG through 1/0 AWG | 200ft | 100ft |
|
|
| 2/0 AWG through 4/0 AWG | 180ft | 80ft |
|
|
| Over 4/0 AWG through 350 kcmil | 135ft | 60ft |
|
|
| Over 350 kcmil through 500 kcmil | 120ft | 50ft |
|
|
| Over 500 kcmil through 750 kcmil | 95ft | 40ft |
|
|
| Over 750 kcmil | 85ft | 35ft |
|
|
|
|
#### 300.19(B) Fire-Rated Cables and Conductors.
|
|
|
|
Support methods and spacing intervals for fire-rated cables and conductors
|
|
shall comply with any restrictions provided in the listing
|
|
of the electrical circuit protective system used
|
|
and in no case shall exceed the values in Table 300.19(A).
|
|
|
|
#### 300.19(C) Support Methods.
|
|
|
|
One of the following methods of support shall be used:
|
|
|
|
1. Clamping devices constructed of or employing insulating wedges
|
|
inserted in the ends of the raceways.
|
|
Where clamping of insulation does not adequately support the cable,
|
|
the conductor also shall be clamped.
|
|
|
|
2. Inserting boxes at the required intervals
|
|
in which insulating supports are installed and secured
|
|
in an approved manner to withstand the weight of the conductors attached thereto,
|
|
the boxes being provided with covers.
|
|
|
|
3. In junction boxes, deflecting the cables not less than 90 degrees
|
|
and carrying them horizontally to a distance not less than twice the diameter of the cable,
|
|
the cables being carried on two or more insulating supports
|
|
and additionally secured thereto by tie wires, if desired.
|
|
Where this method is used, cables shall be supported at intervals
|
|
not greater than 20 percent of the support spacing in Table 300.19(A).
|
|
|
|
4. Other approved means.
|
|
|
|
<!-- TODO: TEXT OMITTED -->
|