What’s the Best Conduit for Outside Use?

Electrical conduit has many necessary uses for a wide variety of projects. Its function is to protect exposed or outdoor wiring from environmental factors, as well as protecting users from danger. However, different types of conduit (such as underwater, below ground, and above ground conduit) are best suited for specific purposes. Depending on environmental factors, budget, regulations, and project specifications, different conduit systems are better suited for different situations. Whatever the particular use, a conduit is vital in protecting homes, offices, warehouses, job sites, and more. Conduit is available in flexible and rigid forms that are made from various materials depending on their intended use.

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Considerations When Choosing Conduit

There are two main kinds of metal conduit, flexible and rigid. Flexible conduit allows you to twist and bend it without using extra hardware, while rigid conduit offers more solid protection but requires additional hardware for joints and bending.

Rigid conduit is often used for commercial purposes, but can also be installed in garages, attics, basements, and crawl spaces. One of the important benefits of rigid conduit is protection against punctures, cuts, nicks, and dings from animals, accidents, and weather. There is a variety of rigid conduit options, including electrical metallic tubing (EMT) that is easy to install and lightweight; galvanized rigid conduit (GRC) which is very thick and the most protective, and intermediate metallic conduit (IMC) which has a thickness between the former two and makes it suitable for outdoor use.

Flexible conduit allows for use around corners and at angles without elbow joints. Prewired conduit, on the other hand (also known as armored cable), comes with wiring already run through it.

When using a metallic conduit, ensure you use electrical boxes as connectors. Failing to do so keeps the conduit from grounding. If the code does not allow for the conduit itself to be used as a grounding conductor, you will need to run a green grounding wire through as well.

Nonmetallic conduit is another alternative that comes in flexible and rigid varieties. Usually, a nonmetallic conduit is made using PVC. It is often the first choice for outdoor residential uses. On the other hand, blue electrical nonmetallic tubing (ENT) is designed for indoor use. PVC fittings are compatible with ENT inside floors, walls, certain ceilings, and encased in concrete. Outdoor flexible nonmetallic conduit is designed to be watertight, durable, corrosion-resistant, and lightweight. Metal and plastic connectors can be used with nonmetallic conduit. However, the nonmetallic conduit should always have a grounding wire running through it.

Above Ground Conduit for Outside Use

Above ground conduit is generally recommended for outside use because of its design specifications. FRE Composites’ above ground fiberglass conduit system includes conduits, conduit bodies, adaptors, and fittings. Designed to provide power, transit, telecommunications, industrial, and commercial clients with a reliable system, it is also lightweight and easy to install. Above ground fiberglass conduit is a secure solution for outdoor use with CSA certification and is UL listed. It complies with above ground specifications in the National Electrical Code for non-hazardous locations and the Canadian Electrical Code. Fiberglass conduit systems are safer, more affordable, and longer-lasting than alternatives.

Related: What is Flexible Housing | Overview, Need & Case Studies (with images)

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