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Example of labeling on PVC electrical conduit

Electrical Conduit Types And Code Referrals

Dear Mr. Electrician: What are electrical conduit types and code referrals?  I would like to know the uses for each conduit type as described in the code book. Answer: Below is a list of the common electrical conduit types installed in North America, with brief descriptions.  The pertaining electrical code article numbers are listed in the  descriptions. The many uses of conduit 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.  NOTE: Text links below go to applicable products on Amazon.com and EBay. Links to conduit dimensions and hole saw sizes are listed at the bottom. Electrical conduit is tested and approved for use with electrical wiring.  Although it may appear to be the same, pipes used for plumbing purposes or fences are not permitted for electrical work.  It is important to match the electrical conduit with the environment it will be in to ensure a quality long lasting electrical installation. Amazon Has Electrical Conduit Bending Books Below is a chart that I found in an old book that shows how to calculate conduit fill.  Conduits are limited to how much space inside the wire can use.  The rest of the space inside the electrical conduit is for air so that the wires can dissipate heat.  Look up Conductor Fill in the index of the National Electrical Code Book. ELECTRICAL CONDUIT TYPES AND CODE REFERRALS ELECTRICAL METALLIC TUBING (EMT or Thin Wall) 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 lists the installation requirements for EMT.  It 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 or Heavy Wall) 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...