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Examples of PVC Schedule 40 Electrical Conduit. The labeling on the conduit is also depicted.

Electrical Conduit Types 2019

Dear Mr. Electrician: I am making plans to build a new house for myself.  I have an architect working on drawings and I want to add some specifications to them.  I do not plan on doing all of the work myself, but I want to be sure that all of my installation requirements are met.  To that end I would like to know the differences between various electrical conduit types to determine what might be best for my particular construction project? Answer: Below is a list with brief descriptions of the common electrical conduit types installed in North America.  The uses are not fully mentioned nor are the code requirements.  Some of that is copyrighted material and would be too long to post here.  Your best bet is to get a copy of the National Electrical Code (NFPA 70) and read the relevant section for each particular electrical conduit type and also for other electrical requirements pertaining to your project.  The electrical code article numbers are listed in the electrical conduit descriptions below.  NOTE: Text links below go to applicable products on Amazon. Links to conduit dimensions are listed at the bottom. Types of Electrical Conduit Used in North America Electrical Metallic Tubing (EMT or Thinwall) is a smooth lightweight galvanized metal conduit that can be used in dry or damp locations.  It is easy to work with and needs appropriate couplings and connectors when joined together or entering a junction box.   EMT can be bent by using the proper bending tool for each of the designated trade sizes.  The standard length for EMT is ten feet 10′ or 3.048 meters.  Pre-bent elbows and twenty foot 20' (6.096 meters) lengths are available for some sizes.  Tables C.1 and C.1(A) in the National Electrical Code (NFPA 70) tell you how many conductors are permitted in EMT conduit.   Article 358 tells you the installation requirements.  EMT is manufactured in several colors to distinguish different electrical systems such as fire alarm circuits from power circuits.  EMT is mostly available in sizes 1/2" to 4" (16mm to 103mm). Rigid Metal Conduit (RMC or Rigid) is a heavy weight metal electrical conduit type with a galvanized finish throughout that can be used indoors, outdoors, and in the ground.  It is factory threaded at each end and is usually furnished with one coupling attached.  Threaded and also compression couplings and connectors are available.  For hazardous locations, explosion proof fittings are available.  The standard length for Rigid is ten feet 10′ or 3.048 meters.  Pre-bent elbows and twenty foot 20' (6.096 meters) lengths are available for some sizes.  RMC can be bent using the correct bending tool for each of the designated sizes.  Tables C.9 and C.9(A) in the National Electrical Code (NFPA 70) tell you how many conductors are permitted in RMC conduit.  See Article 344 for code installation requirements.  Rigid is available in 1/2" to 6" sizes or 16mm to 155mm. Intermediate Metal Conduit (IMC) is a lighter weight version of RMC.  It has a galvanized finish inside and out...