What is an Electrical Conduit : Working & Its Applications

Electrical engineer or electrician designs electrical wiring at homes using different associated devices like sockets, switches, distribution boards, etc but the designer has to decide which type of wiring has to use. At present in modern homes, the most common type of wiring is used in nonmetallic cable form which includes a minimum of two or more separate wires that are enclosed in a protective plastic sheathing. So selecting the suitable type of wiring & the right electrical conduit is essential. This electrical conduit provides proper protection for wiring from damage. So this article discusses an overview of what is an Electrical Conduit, its types & its working with applications.


What is an Electrical Conduit?

Electrical conduit definition is, it is  a durable tube or enclosure where electrical wires are enclosed for protection from damage. Sometimes, these are also called wire ways or raceways. Electrical conduit is very essential where the electric wiring is exposed so that it protects the wires & individuals who may approach near the electric wires. The material used to make this conduit is plastic or metal and may be bendable or stiff. The electrical conduit diagram is shown below.

Electrical Conduit
Electrical Conduit

The US NEC (National Electrical Code) as well as local building codes, make a decision when should be a conduit is used in a particular installation & which type of electrical conduit should be utilized. The installation of all electrical conduits can be done by using compatible fittings like elbows, couplings, connectors & electrical boxes which are made with similar material.

How does Electrical Conduit Work?

The electrical conduit works by providing adequate protection for homes, buildings from electrocution. Generally, conduits allow different wires to run current safely throughout the same pipe. The correct time to utilize an electrical conduit is whenever you are running a wire manually for electricity or when re-wiring a home.

Before using an electric conduit, we need to verify the building codes as well as its regulations, because there are some rules to install conduits. Generally, conduits are made with different materials like fiber, metal, plastic, fired clay based on the requirement. These are installed by engineers or electricians at the installation site of electrical equipment.

Specifications

The specifications of the PVC Electrical Conduit include the following.

  • The size of the conduit is 25 mm.
  • The material used is PVC.
  • Medium type.
  • 3-meter length.
  • The diameter is 20mm.
  • Weight is 12.5 KG.
  • Used for electrical wiring.
  • The type of conduit is Hollow.
  • Available colors are Black, Blue, Yellow, Red, Brown, Green, Cream, Grey &White.

Types of Electrical Conduit

There are different types of electrical conduits that are commonly used in residential and other commercial buildings. They are;

  • Electrical Metallic Tubing.
  • Rigid Metal Conduit.
  • Intermediate Metal Conduit.
  • Flexible Metal Conduit.
  • Liquid-tight Flexible Metal.
  • Electrical Non-Metallic Tubing.
  • Rigid PVC Conduit.
Types of Electrical Conduit
Types of Electrical Conduit

Electrical Metallic Tubing

Electrical Metallic Tubing or EMT is a common example of an unbending electric conduit. This type of conduit is made with Aluminum or Galvanized steel. As compared to Rigid Metal Conduit (RMC), it is lighter and thinner but it can also be strong and bendable with using a tube bender tool, so it is known as a thin wall conduit.

The installation of electrical metallic tubing can be done with couplings & fittings that are protected completely through setscrew or compression-type fasteners. Similar to IMC & RMC, EMT is not threaded but these are available in common sizes like ½, ¾ & 1 inch.

These conduits are used most frequently in indoor wiring like residential & commercial buildings. If these conduits are used outdoors in exposed areas, they should be connected through special watertight fittings.

Rigid Metal Conduit

The rigid metal conduit or RMC is very expensively available electrical wiring in the market because it provides extra power & strength. It is made with heavyweight Galvanized Steel and installed with threaded fittings.

This type of conduit is commonly used outdoors for providing safety from damage & also provides structural support to panels, cables & different equipment. These are available in 10 to 20 feet lengths with threads on each side of them.

Intermediate Metal Conduit

A Lightweight & thinner version of RMC is IMC which is used in the same applications as RMC. Because this conduit is lighter & very easier to work as compared to RMC, it is more frequently used in new constructions.

IMC is rated for outside exposure & used for protecting conductors & insulated electrical cables. It is a very economical choice for projects wherever the price is an issue.

Flexible Metal Conduit

FMC (Flexible metal conduit) is available in a spiral construction and it is flexible so that it can simply bend throughout different structures & walls. A typical flexible metal conduit is used in indoor locations which are dried out and used at fixed appliances like a garbage disposer. These conduits are mainly guard’s electrical wiring in industrial & commercial buildings.

The FMC is the best choice to use in different areas and the best examples of basic FMC are water heaters, attic vents, & lights installations.

Liquid-tight Flexible Metal

The liquid-tight flexible metal conduit or LFMC is a special type of FMC. This conduit is available with a plastic coating, so used with sealed fittings to make it waterproof. It is frequently used with outdoor equipment like AC (air conditioner) units. So this type of conduit is mainly designed for utilizing in locations where dampness could become a problem. This type of conduit should be used in combination with liquid-tight fittings.

Electrical Non-Metallic Tubing

Electrical nonmetallic tubing or ENT is a flexible and thin-walled corrugated plastic conduit and it is flame-retardant & moisture-resistant. This type of conduit is very simple to bend & installed with glued plastic & snap-lock fittings.

Not like electrical metallic tubing (EMT), this conduit cannot be used in exposed locations but used inside walls. In addition, to use in normal metal-frame or wood walls, electrical metallic tubing can be used in concrete block constructions &can be roofed with concrete. As compared to RNC, this ENT-type conduit is very easy to use because it can be turned around the wall without welding or cutting.

PVC Conduit

PVC conduit or polyvinyl chloride conduit is related to plastic plumbing pipes. These conduits can be simply installed by plastic fittings with glue. It can be simply bent once heated within a heater box. These conduits can be used in underground and corrosive environments.

The main benefits of using these conduits are, installation is easy, versatile, less weight, not expensive, used in underground and concrete.

Electrical Conduit Diameter Chart

We know that there are different types of electrical conduits available in that market that are used based on the requirement. So the diameters of each type vary in terms of radius, inside and outside diameters. Here is the diameter chart for the electrical metallic tubing conduit.

Size of Trade Inside Diameter Outside Diameter

Radius

1/2

0.622 0.706 0.311

3/4

0.824 0.922

0.412

1

1.049 1.163 0.525
1 to 1/4 1.380 1.510

0.690

1 to 1/2

1.610 1.740 0.805
2 2.067 2.197

1.034

2 to 1/2

2.371 2.875 1.366
3 3.356 3.500

1.678

3 to 1/2 3.834 4.000

1.917

4 4.334 4.500

2.164

When to use Conduit for Electrical Wiring?

Electrical conduits are used whenever electric wires are buried or exposed in homes or buildings. So, exposed electric wires need safety from different elements like moisture, dust, weather, extreme heat, cold, etc & also people require safety from the risk of electric shock. So it is very essential to know how to install, handle and protect electric wires by hiring an electrician or engineer.

So the main purpose of the conduit is to defend the electrical wiring at homes, offices, buildings, etc. Conduit is not required in most cases when electric wiring is installed inside the home walls or in ceilings.

How many wires can be in a conduit?

The electrical wires used in an electric conduit mainly depend on different factors like cable size, type of conduit, and size of conduit. Here, the size of a wire can be defined simply by the AWG which is known as the American Wire Gauge number. When the AWG number is small then the wire diameter is larger. The following tabular form lists the type of conduit, size, and cables used.

Conduit Size & Type 8 AWG Wire 10 AWG Wire 12 AWG Wire 14 AWG Wire
1/2-inch EMT

3

5 9

12

3/4-inch EMT

6

10 6

22

1-inch EMT

9

16 26

35

1 1/2-inch  EMT

22

38 61

84

1/2-inch PVC—Sch 40

3

5 8

11

3/4-inch PVC—Sch 40

4

9 15

21

1-inch  PVC—Sch 40

9

15 25

34

1 1/2-inch PVC—Sch 40

21

37 59

82

1/2-inch PVC—Sch 80

2

4 6

9

3/4-inch PVC—Sch 80

4

7 12

17

1-inch PVC—Sch 80

7

13 20

28

1 1/2-inch PVC—Sch 80

18

32 51

70

1/2-inch FMC  13

3

6 9

13

3/4-inch  FMC 22

6

10 16

22

1-inch FMC

9 15 24

33

How deep should an electrical conduit be buried?

A metal conduit can be buried as a minimum of 6 inches under the ground. They can also be buried in 4 inches depth in the concrete slab. Under private roads, these conduits should be buried under 18 inches depth whereas, under public roads, they should be buried under 24 inches.

Does underground electrical wire need to be in conduit?

No, because in undergrounds, direct burial cables are directly installed without using conduit. The construction of direct buried cables has water resistance to function under the soil for many years once they are installed properly.

How does conduit work electrical?

A conduit is a tube where electrical wires are enclosed for various structural and building applications. It protects enclosed wires & also any individuals who may approach near to the electric wires.

What is GREY conduit used for?

The grey color conduits like electrical conduit PVC are UV Resistant & the green shade is a sign for electrical wiring used for hydraulic applications.

Advantages

The advantages of electric conduit include the following.

  • These wiring systems are waterproof.
  • Its appearance is good.
  • Long life.
  • Alternation is achievable.
  • It is consistent.
  • It is a strong & very famous system.
  • PVC type’s conduits are highly resistant to corrosion.
  • There is no possibility for fire.
  • Protection from electric shock.
  • Easy maintenance.
  • When cables are damaged, we can replace them easily.
  • It provides protection from chemicals, moisture, etc.

Disadvantages

The disadvantages of electric conduit include the following.

  • Installation is not easy.
  • Very difficult to find the fault.
  • Expensive.
  • Takes more time while installation.
  • Electric shock risk.
  • Maintaining extra connections is complicated in the future.
  • As compared to the concealed system, this wiring system beauty is less.
  • Mechanical damage is possible in PVC plastic conduits.

Applications

The applications of electric conduit include the following.

  • Electrical conduit is available in different types and styles which are used to run electrical wiring around your home or exposed areas like a garage, basement, laundry areas, barn, etc.
  • Electrical metal conduit (EMC) is used in commercial, industrial & residential constructions
    The flexible metal conduit (FMC) is used to connect lighting fixtures and on top of suspended ceilings.
    A rigid metal conduit (RMC) is mainly used in outdoor applications for providing structural support mainly for electrical cables.
  • Intermediate metal conduit (IMC) is mainly used for strong connections & outdoor exposures.
    IMCs can be used as an equipment grounding conductor through their fittings.
  • Liquid-tight flexible metal conduit (LTFMC) is mainly used for connecting outside AC equipment or & also disposals in kitchen sinks. In residence, its usage is quite restricted.
  • Rigid polyvinyl chloride (RPC) is mainly used in wet areas & they have good resistance to highly acidic chemicals.
  • RPC is completely waterproof, so perfect for wet locations in commercial and industrial buildings.

Thus, this is all about an overview of an electrical conduit, types & its applications. From the above information, finally, we can conclude that electrical conduits are very essential for protecting the wiring system in homes, buildings, commercial buildings from moisture, dust, chemical vapors, impact, etc.
These are made with different materials like plastic, metal, fired clay, or fiber. Most of the conduits are inflexible, although flexible type’s conduits are used mainly for some specific purposes. Here is a question for you, what are the colors of conduits available in the market?

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