For any electrical project in residential settings, electricians always start by determining the type of wiring to be used. It is the most crucial and foremost decision as the right wiring makes their work easier and eliminates inconsistencies. The next thing they discuss is conduit fitting to enclose the wires and protect the route for wiring conductors. Undoubtedly, it is an essential aspect of the project that not only electricians but also homeowners must be aware of.
Here is a homeowners’ guide to conduit fittings, discussing each of its common types in brief:
What Is an Electrical Conduit?
In a wiring system, most circuits are in insulated cable form, running inside walls, ceilings, and floors without conduit, which is a plastic or metal pipe used to run wires through. Electrical conduit fittings are used where circuit wires are exposed or buried, such as the exterior wall surface. It is also used to enclose wires at unfinished locations, including basements, attics, and surface-mounted outdoors. Therefore, safeguarding cables and conductors from damage or moisture.
For a standard installation process, a compatible raceway, which includes connectors, couplings, and electrical boxes, is installed. These items are made using the same material as conduits. After this, individual wire is run through the tubes using a flexible metal ribbon, commonly called fish tape. Each conduit has a different type of fittings (that connect their lengths) and connectors (to join conduit boxes).
The couplings, elbows, and tees used in conduit fittings are used for extending or changing their direction. Some of them have removable plates or covers to provide access to conduit interiors.
Types of Electrical Conduit Fittings
Electrical Metallic Tube (EMT)
EMT is a common unbending conduit fitting made of galvanised steel and at times, aluminium as well. Used for exposed interior installations, such as workshops and basements, it is the lightest and thinnest conduit, thus, also known as ‘thin-wall.’ Although these fittings are quite rigid, you can bend tubes using a conduit blender.
EMT’s standard size for household circuits is 1.5 inches. National Electrical Code (NEC) permitted it for dry and indoor locations but if you want to use it outdoors, use special watertight fittings and connectors.
Electrical Non-Metallic Tube (ENT)
ENT is a flexible corrugated plastic tube installed using glued plastic fittings or snap locks. For metal-frame walls or standard woods, this conduit fitting can be installed within concrete block structures. Because of its blue colour, it is also called a smurfing tube.
ENT consists of waterproof tubes that are also fire resistant. They are also known for their unique protective qualities, making them an ideal pick for indoor and outdoor fittings.
Rigid Metal Conduit (RMC)
RMC is made of heavyweight galvanised steel and installed using threaded fittings. As it is tough, you can use it outdoors to protect cables from damage. Moreover, these conduit fittings provide structural support for electrical panels, cables, and other equipment.
You can get RMC in 10 and 20 feet lengths and they must have threads on both ends. Rigid metal is comparatively more expensive but the durability and strength it offers are worth the price.
Intermediate Metal Conduit (IMC)
IMC is more of a thinner and lighter version of RMC but it provides the same level of protection. If a project has a restricted budget, then IMC is an economical alternative to other expensive fittings. It is equally approved so you can use it in similar applications like RMC. As they are lightweight, people prefer them more for construction projects.
Flexible Metal Conduit (FMC)
Flexible Metal Conduit is also known as “Greenfield,” a name derived from its inventor. It is a spiral metal tube, hence, extremely flexible to snake through walls and other structures. Because they bend easily, standard FMC fittings are generally used indoors.
This conduit is a great substitute for areas that need close quarters and tighter bends. Also, it is a perfect choice for connecting attic vents, lights, furnaces, and heaters.
Liquid-tight Flexible Metal Conduit (LMFC)
LMFC is a flexible conduit with a coating of waterproof plastic sheathing. So, you can use it in dry and wet locations. This metal conduit fitting is commonly used to protect cables between an outdoor AC unit and its disconnect switch.
LMFC uses a special threaded connector to ensure water tightness. Also, it can be buried if you are using approved material.
Rigid PVC Conduit
Rigid Polyvinyl Chloride or PVC is a thinner version of plastic plumbing pipe and can be used in corrosive environments. For installation, it uses plastic fittings that are glued directly in place. You can bend the conduit after heating it to change its direction easily.
As conduits are glued together, they can be watertight. It has been proven that PVC is suitable for quick burial along with several other applications.
Select the best from the mentioned options and seek the benefits of well-developed conduit fittings made from metal, plastic, and fiberglass. These compatible fittings facilitate wire pulling and routine tasks while enhancing safety and preventing damages. We hope that now you are more familiar with electrical conduit fittings and will be able to use them in several ways in your electrical wiring system.