An electrical conduit creates a path for wiring conductors and covers them for protection. EMT is an example of an electrical conduit; it can be aluminum or galvanized steel. But does it need to be grounded?
Does EMT Conduit Need To Be Grounded?
Yes, you need to ground electrical metallic tubing (EMT). You should ground it to the grounding conductor of the system. You can do this in many ways; it depends on the size, installation, etc. The EMT lengths are bonded to each other by the EMT coupling bonds. However, the conduit system is bonded to the equipment by the connectors.
The approved connectors you can find in the junction boxes are bonded to the grounding conductor in the conduit system of the equipment. Meanwhile, to keep the consistent ground, potential splices are made, and different connections. You should know that some equipment needs the installation of grounding bushings.
Despite that grounding and bonding are essential parts of any safe installation of electrical devices, you may see a lot of violations. This violation can lead to dangerous situations for users; the grounding is responsible for dispersing any power surge. You should always consult professional electricians for any electrical work.
Can EMT Conduit Be Used Outside?
Yes, you can use electrical metallic tubing (EMT) outside, indoor, or underground. You can also use EMT in any type of device, whether it is an exposed or covered device. EMT is known to be lightest than any steel conduit. Meanwhile, RMC and IMC can be used for the same tasks; IMC has less weight and thin walls.
Do You Need to Conduit Outdoor Wiring?
According to the local codes, the outdoor wiring needs to be inside the conduit. For example, if you have outdoor wiring that is not buried, you need to cover it inside the conduit; for your protection. However, if you have concealed wiring, then according to most codes, you can use UF cables. But you should know that sometimes you may need to use TW wire and conduit.
Is EMT Weatherproof?
No electrical metallic tubing is not weatherproof. Some wires are water-proof, but this doesn’t mean wires can be soaked into water. So this implies conduit or boxes will fail. However, EMT tends to resist rust for some years, but eventually, it will rust either at its ends or where its finish is cracked.
Where Is EMT Used?
If you have an area that will need tight bends, you should use the flexible metal conduit, as it is hard to bend a regular conduit. This conduit type is used to cover wires, especially when you have pets, so it acts as a protective hurdle if it gets chewed. For example, you can find a flexible metal conduit in attic vents or water heaters.
Can EMT Conduit Be Used in Concrete?
Yes, you can use EMT, and it’s fitting, couplings or elbows in concrete. It can be subjected to earth or corrosive factors, but you need to cover it with corrosion protection.
What Are the Types of Electrical Conduits?
EC is short for electrical conduit, which means solid tubing or any other type of cover can create paths for wiring and protection. When wires are exposed, they need to be covered to protect them from damage. The conduit has two different forms; it may be rigid or flexible. The material can be either plastic or metal.
Any conduit should be installed with compatible fittings and electrical boxes, for example, elbows, connectors, and couplings. These fittings or boxes can be made of similar material or the conduit’s material. All conduits are subjected to the national electrical (NEC) and local codes.
Electrical conduit has different types, and these types are:
1. Electrical Metallic Tubing (EMT)
EMT is short for electrical metallic tubing. It’s made of galvanized steel in general; however, it can be aluminum. It’s a thin-wall conduit because it has lightweight and thin walls. Although the EMT is rigid, you can use a conduit bender to bend it.
Compression-type fasteners or setscrews are used to secure the electrical metallic tubing and compatible fittings and couplings during installation. However, the EMT is doesn’t have threaded tubing as in IMC and RMC. The electric metallic tubing has 1/2, 3/4, and 1-inch different sizing.
You can use EMT in exposed areas indoor, which is especially used in light construction and residential. You can’t use it outdoor unless you use a watertight fitting for protection.
2. Electrical Non-Metallic Tubing (ENT)
ENT is used in extreme conditions because it’s flame-retardant and moisture-resistant. It’s made of corrugated flexible plastic, which you can bend easily and install in plastic glued fitting or snap-lock. The electrical non-metallic tubing is used inside walls; it can not be used in exposed areas.
The ENT has an advantage which, it can be covered in concrete and installed inside the concrete. Of course, it can be installed in wood or metal walls as most conduits. ENT is known as Smurf Tube due to its blue color; the smurf name came from the famous cartoon smurfs.
3. Rigid Metal Conduit (RMC – IMC)
- RMC is famous for being made of heavy galvanized steel and threaded fittings. So it is used for the support of panels, electric cables, and different equipment and protects from damage. Its ends have threads; the RMC length varies from 10 to 20 feet.
- IMC is short for intermediate metal conduit; it’s a version of RMC but has thin walls and less weight. IMC can be used in all the applications of RMC. You can find IMC in new constructions because it’s easier to handle than RMC.
4. Flexible Metal Conduit (FMC – LFMC)
- The flexible metal conduit is known as Greenfield, which is the FMC inventor. It can be used through structures and walls due to its flexibility and spiral construction. You can find flexible metal conduits indoors in dry locations. For example, it can be between a device and a wall box, such as the disposer of the garage.
- LFMC or the liquid-tight flexible metal conduit is a version of the flexible metal conduit. The major difference between them is that LFMC has a coating made of plastic. When using LFMC, you should use covered fittings to make the conduit watertight. The LFMC is used in outdoor devices, for example, units of air conditioning.
5. Rigid PVC Conduit (PVC)
PVC is short for polyvinyl chloride; it’s generally used in water pipes in plumbing. The rigid PVC conduit is used with glued fittings during installation. To bend it, you can use a heater box. The rigid PVC conduit is used in corrosive areas or can be buried in the ground due to its fittings glued together in place, so it’s watertight.
What Conduit Is Suitable for Outdoor Usage?
PVC is the most suitable conduit for outdoor usage and applications. You can use it either buried in the ground or above areas that contain work. Due to its lightweight and versatility, it’s also found in different grades and thicknesses.
Is PVC conduit better than EMT conduit?
Yes, PVC is considered better than EMT when it comes to underground work. The electrical metallic tubing is known for having lightweight, and it’s used in conduits inside the walls due to its bendable material. So EMT can be easily damaged if used in underground work. PVC is more suitable for underground work.
In general, EMT has limited usage due to its properties. For example, you can not use EMT under these conditions:
- EMT can not be used during or after the installation process because it’s made of bendable material that can be damaged during the process.
- You can’t use EMT in corrosion areas if the protective barrier is enamel only.
Can FMC be used outdoor instead of PVC?
No, you can not use FMC instead of PVC in outdoor applications. The flexible metallic conduit is made out of aluminum. So you can not use it in wet areas or areas exposed to water. FMC has limited usage due to its material; however, it can be used in some applications. Meanwhile, the rigid PVC conduit is more suitable for outdoor usage.
Is IMC Used for the Same Applications of EMC?
No, IMC has different applications, but it completes EMC.
- EMC is found mainly in-home wiring, especially the exposed wires. You can also find EMC in commercial buildings.
- IMC has limited usage in-home wiring; however, it can be used in the wiring of the exterior panels and the assemblies of the entrance.
Do You Need To Use Conduit for Outdoor Wiring?
Yes, outdoor wiring needs to be protected in conduit. However, some wires are made of protective covers, protected from sunlight and weather conditions. This means if the wires are not protected, you need to use conduits or other protection methods. In addition, you should know that not all plastic is suitable for outdoor usage.
You also have to check for your country’s regulations. For example, in the UK, it’s specified that all wires outdoor must be protected from mechanical damage. You can do this by conducting the cables and burying them or using conduits. If you are not burning the wires, you should consider the effects of the UV.
EMT or electrical metallic tubing is a type of metal conduit. It’s used as a protective cover for wiring indoors. Despite that, it has a protective job for the electrical wires, but it needs to be grounded the same as the cables. EMT is the standard conduit for house wiring; it can’t be used outdoors due to its material easily bending.
However, there are many types of conduit that can be used outdoor. For example, PVC is the most suitable conduit for outdoor usage. This is due to its material and glued in place fittings and components.
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