How to out wiring system for industrial, commercial, and residential installations depends upon the composition, application, voltage, load, appearance, cost,
and elements. The different types of electrical conduits are defined in detail below.
Different kinds of electrical conduit
The most common types of electric conduits are:
Rigid metallic conduit( RMC)
In this approach, all wires are enclosed in a typical pipe known as a channel. The pipe is usually steel, sometimes aluminum, or brass( especially for going swimming pool lighting). Conduit varies from a faucet in that the interior surface is carefully prepared so wires can be drawn in it with a minimum amount of effort minus harm to their insulation. Likewise, the chemical composition of the steel in the conduit is carefully managed so it will flex easily. Steel conduit usually has a galvanized or similar finish inside and outside. Some galvanized metal conduits plus some aluminum canals have an additional teeth enamel or plastic coating for further protection against corrosion.
More complex metal conduit( IMC)
This really is similar to ordinary strict metal conduit and, size for size has the same outside diameter but thinner walls. Which makes the interior area in square inches some more within the ordinary channel, and that positive change often makes a huge difference in allowable wire stock up. IMC is installed in the same way as ordinary RMC. The strings are identical and RMC fittings can be used without modification. It is more likely to twist due to the reduced wall thickness, which makes it less tolerant of conduit hickeys. Conduit benders work nicely. The only real application difference between the two products is that RMC is made in most trade sizes up to 6 in., but IMC goes only up to 4 in.
Both RMC and IMC can support boxes that have threaded hubs or conventional sheet metallic boxes to which hubs recognized for this goal were added.
Electric metallic tubing( EMT)
Some raceway that is similar to rigid metal channel but of thin-wall structure construction is known as “electrical metal tubing“( abbreviated EMT).
This is made of zinc-coated steel or occasionally of aluminum, either of which might have additional plastic or other protective coatings. The laws that put on rigid metal conduits— such as the volume of cables permitted, bending, and supports— apply in order to EMTs. It is made only in sizes through 4 in. This must be supported within 3 ft of every box, cabinet, or fitted, and also at intervals not exceeding 10 ft, irrespective of size. If there is no structural component designed for support, the pioneer point of support might in so far as 5 ft belonging to the end of the contract, provided the intervening tubes includes an uncut scale EMT. In addition, an unbroken duration of EMT can be fished. This kind of may appear odd, but there are cases where you might be able to stick a length of tubes down into a wall structure cavity.
The internal size in the smaller sizes is equivalent to in rigid conduit, however, in the larger sizes, it is a little larger. Nevertheless, because they are so thin, EMT must never be threaded during a call( there is a patent in existence for a factory-threaded product, but it is not very present in production). Rather, all joints and contacts are made with threadless fittings that hold the material through pressure.