Understanding the Various Types of Electrical Conduits

Electrical conduits are tubes through which electrical wires are fed into the house and threaded into the overall electrical system. Conduits are necessary wherever a wire may be exposed to and is at risk of being damaged, making them essential both indoors and outdoors. Each conduit usually can hold two or more separate insulated wires. The conduit ends are connected to one another via various fittings and connectors and the rest of the house.

There are seven common electrical conduit types in modern house construction that homeowners and electricians alike should know.

Electrical metal tubing (EMT)

EMT is the most common conduit for interior exposed installations like unfinished garages, basements, or attics. The tubes are usually made of galvanized steel or aluminum. They are rigid but can be bent into the required shape with a special tool. EMT conduits are often referred to as thin-wall tubing because they are more lightweight and thinner than other tubing types. The standard tubing sizes are 1 inch or 1½ inches. Since they run alongside interior walls, they need waterproof fittings to provide a watertight seal.

Rigid metal conduit (RMC)

The RMC is made from durable galvanized steel equipped with threaded fittings. It’s most often used outdoors and can provide electrical boxes and panels with added structural support and stability. More often than not, this is the most expensive tubing type and has a minimum 10-foot length, but it’s simply the most durable for outdoor applications. It can also be buried for other applications.

Intermediate metal conduit (IMC)

The IMC is commonly used to replace the more durable and expensive RMC for residential applications. It is more lightweight and thinner than the RMC but offers a similar level of protection to the wires. Construction crews may use IMCs instead of RMCs for larger projects to cut down on costs.

Flexible metal conduit (FMC)

Made of spiraling metal tubing, the FMC is easier to bend and commonly used in indoor applications. It can be threaded through walls and is usually used to connect furnaces, lighting, and attic vents. It’s great in tight corners where other conduits can’t fit. FMCs can only be used in dry areas.

Liquid-tight flexible metal conduit (LFMC)

The LFMC is FMC tubing coated with waterproof plastic sheathing. The additional plastic coating makes it suitable for wet areas and LFMCs usable for water heaters and air conditioners. It can also handle being buried for specific applications.

Electrical nonmetallic tubing (ENT)

ENT is made from plastic and is a waterproof, flame-retardant corrugated tubing. It is pliable by hand, allowing it to fit within close quarters. Its protective qualities make it suitable for various indoor and outdoor applications, including fitting it inside concrete structures. It’s usually blue, which is why it’s often called a smurfing tube.

Rigid PVC

This plastic tubing is mainly used in corrosive environments. It can be heated up inside a special box to become more pliable and is glued to its waterproof fittings to provide a watertight seal. PVC is excellent for quick burials during construction and is easy to install. Despite being suitable for wet and dry environments, UV light from the sun will degrade the tube over time.

Installing the correct electrical conduit will enhance house safety and prevent health hazards. Contact a qualified electrical service for quotes on electrical conduits during construction or renovations.

If you need a highly-reviewed, licensed electrician in the Phoenix Valley area, call Efficient Electric at 623-900-1461. We would love to hear from you!