Plastic conduit is an affordable, adequate alternative to armoured cable and metal conduit. Plastic conduit is made of polyvinyl chloride, or PVC; PVC is a tough plastic and suitable insulator for electrical wiring systems. The plastic fittings are secured to the pipes with special PVC cement. When planning a run of plastic conduit, try to keep fittings and joints to a minimum; fittings are expensive and more time-consuming to install than straight runs.
Measure the total run of conduit you need for your project. Account for fittings, joints and electrical boxes.
Cut the conduit at a clean, 90-degree angle with a hacksaw, a back saw and mitre box or a power saw equipped with a plywood saw blade. Deburr the pipe ends with a deburring tool or pliers to remove jagged pieces from the severed end.
Use a rag to clean the pipe end. Wipe the inside of the fitting, as well.
Apply a small amount of PVC primer to the pipe end and to the inside of the fitting where you will insert the pipe end. Allow a few seconds for the primer to dry.
Apply the PVC cement to the pipe end and the inside of the fitting where you will insert the pipe end. Immediately insert the pipe end into the fitting. Twist the pipe end slightly (1/4 of a turn) until the pipe end is fully in the fitting. The cement dries very quickly, so you must attach the sections within 15 seconds. Allow the joint to cure for 5 minutes before attempting the next joint.
Wipe off excess cement with the other clean rag.
Repeat steps 2 through 6 until your run is completed. Snake the electrical wires through your conduit when the final connection is completely dry and cured.
Before cementing the plastic pipes and fittings, conduct a "dry run" by attaching the system together. This will ensure that your measurements are accurate. Mark the pipes and fittings with a marker: draw small alignment lines across every joint, so that when you are ready to cement the system together, you can follow your alignment marks for a perfect fit.
Although plastic conduit is listed by the Underwriters Laboratories and conforms to NEMA TC-2 standards, check with your municipal codes department to determine if plastic conduit is an approved material for electrical systems in your area. Do not install plastic conduit underground unless the conduit is specifically labelled for underground use. Do not install plastic conduit in a sunny location, as the plastic breaks down and weakens under the sun's rays. Long runs of conduit must be supported by spacers and special plastic conduit hangers. The size and spacing of hangers depends on the pipe diameter of your conduit and the regulations set forth by local codes. Check with your municipal codes department to determine proper support placement for plastic conduit.