What are Electrical conduits
An electrical conduit is a tubing system which is used for the protection and routing of the electrical wire. It is mostly made up of metal, plastic, fiber, or fired clay and flexible conduits are used for special purpose These piping systems are also known as raceways
There are many types of conduit available the outdoor conduits are mostly for exterior use metal conduits should only be used with metal boxes, not with plastic boxes
Types of conduits
The conduits are classified by its mechanical stiffness and the material which is used to make the conduit. For electrical equipment In hazardous areas must need particular conduits for the protection of the electrical wire
Rigid metal conduit / Rigid steel conduit
These are the heaviest and thickest conduits they are mostly made up of coated steel, stainless steel, red brass. This can be installed above or below the ground it is mostly corrosive resistant.
- Rigid steel conduits should be used when exceptional mechanical protection is needed
- It should be used when conduits are used above ground in outdoor industrial facilities
Rigid nonmetallic conduit (PVC)
PVC is made from the combination of plastic and vinyl it can be used in above ground, underground or encased in cement. It is mostly used for an underground purpose, they are flexible, impact-resistant, non-conductive, ultraviolet resistant and corrosion-resistant. They are popular because of the watertight joints and low installation costs
Galvanized rigid conduit
They are created by galvanizing the RMC, RSD via hot dipping it in zinc. The zinc coating will provide extra coating where areas that are wet or highly corrosive it is interchangeable with most RMC and RSD. PVC coating can be added on top of the GRC coating for conduits which is exposed to chemicals and other highly abrasive materials
Intermediate metal conduit
It is a steel tubing which is heavier than the EMT but heavier than the RMC and it may be threaded
Electrical metallic tubing
Its construction is similar to the rigid steel conduit except that it has constructed with a thinner material it is referred to as a thin wall conduit. EMT is not threaded and it is joined by threadless couplings
- EMT should be used in non-hazardous indoor locations
- It must not be used where corrosion can cause damage
- It must not be used in places where it could be subjected to physical damage
Flexible metal conduit
In places which must sustain a large number of vibrations and movement this conduit can be used they are made up of a single strip of aluminum or galvanized steel which is spirally wound or interlocked, the interlock construction of this conduit will provide a round cross-section which has a high degree of mechanical strength and great flexibility
What are the conduits used for underground applications
Conduits are installed underground between buildings and structures to do the installation of the power and communication cables. Mostly metal conduits are used for underground applications but PVC is also used polyethylene or polystyrene plastics are used nowadays because of the low cost, easier installation and corrosion resistant
Non-metallic conduit fittings
They are solvent welded to non-metallic conduit it can be threaded and screwed into threaded fittings or attached with setscrews or compression fittings
How can we do electrical grounding in metal conduit
Install a green electrical grounding wire for any circuit which runs through a metal conduit a green insulated wire is installed for grounding the system. The grounding wires should be connected to metal boxes with a pigtail and grounding screw
What are the electrical fittings which are used to connect the conduit
Box connectors – it is used to join the conduit to a junction box or other electrical box
Couplings – they are used to connect two pieces of conduit together
