Conduit
As wires run from one connection point to another, they should be placed in some type of conduit to protect them from physical damage that can result from abrasion, contraction and expansion, the sun, rodents or chemicals. The term conduit refers to a variety of different types of plastic or metal forms of protection that can be used. The appropriate type of conduit will vary based upon:
1. Where the wire/conduit will be located. What will offer the best protection given the conditions. For example, if conduit will be located outside, it is necessary to choose a conduit that is appropriate for use in wet conditions.
2. Building construction. Will the conduit/wiring be run inside a wall? If it is to be run inside a wall, an appropriate conduit should be chosen. On the surface of a wall? Various conduit types may offer sufficient protection, but some may be more aesthetically pleasing than others.
3. The local electrical code/local practices. It is the best practice to follow the electrical code in any given location, but local practices may dictate a different approach.
4. Local availability of materials. Some components and materials are not available in all locations.
Conduit types
There are several broad categories that most types of conduit fit into. The actual appearance of the conduit, connectors, and couplers may vary from place to place. Metallic conduit can be bent into angles with appropriate bending tools or sections can be bought that are pre-bent to specific angles (15°, 30°, 45°, 90°)
Metallic conduit
Metallic conduit offers excellent protection. It is slightly more costly than other options, but will result in a high quality installation if used appropriately. There are a few different types of metallic conduit available which are classified based upon the thickness of the walls of the tubing:
- Electric metallic tube (EMT): The thinnest options which is intended for use indoors - on walls or inside walls.
- Intermediate metal conduit (IMC): A thicker-walled option that offers more durable protection. Can be installed outdoors with appropriate connectors/couplers/junction boxes.
- Rigid metal conduit (RMC): The thickest-walled option that is the most durable. Can be instsalled outdoors with appropriate connectors/couplers/junction boxes.
Additional considerations: -Size