How To Connect PVC Conduit To An Electrical Box (Do This!)
The grey pipe or the conduit PVC pipe is designed to handle the heat of the sun and the heat of the electrical wires. Two different kinds are used in electrical work, which are Schedule 40 and Schedule 80. Either or can connect to an electrical box.
Many people may prefer to do things on their own. But it is best to get a professional to check your work when it comes to electrical. One of these times is working to connect a PVC conduit to an electrical box.
To connect PVC conduit to an electrical box, you will need fittings, threaded hubs, PVC cement, end bushings, and locknuts. Put the fittings on the pipe first; then, pull the wires through the conduit with fish tape. Once everything is dry, after putting the pieces together, the cement bonds as a waterproof joint.
Valuable Information on PVC Conduit
As many already know, there is a difference in the PVC pipes on the market. Knowing which one to use is critical to the reliability of each purpose. When doing a PVC pipe job, no one wants to go back and do the same task twice.
Each pipe has its different color codes to label them. White is for plumbing and can only handle liquid temperatures up to 140 degrees. Black is CPVC and is designed for hot water up to 200 degrees.
The color grey is the one we will be discussing in this article which is made for electrical work. It is known as PVC conduit pipe and is tested to stand up to the hottest temperatures in electrical wiring. There are two different kinds of PVC conduit, and they are both lightweight and cheap.
Schedule 40 PVC Conduit
Schedule 40 PVC is the cheaper of the two types. This one has a larger diameter inside to make it easier to pull the wires through. It has a thinner layer of plastic, but the diameter of the entire pipe remains the same.
Schedule 80 PVC Conduit
Schedule 80 PVC is a little more in cost than the 40 but is still affordable and reasonable in price. This one has a thicker layer of plastic for added protection. The diameter inside is smaller than the 40, but the width of the pipe is the same as the measurements.
Schedule 80 is made for high traffic areas where it is safer around people. It is also ideal for hazardous locations. Schedule 40 is mainly used in areas of seclusion.
The Best Wire to Use with PVC Conduit
Thermoplastic high heat-resistant nylon-coated (THHN) is the most highly recommended wire for use with PVC conduit. Other cables are made with different rubber sheathing that is sticky and tough to pull through. Most commercial jobs favor this wire as it is flexible and is easier to fit inside an electrical box.
Steps to Connect the PVC Conduit to the Electrical Box
These are the steps in connecting the PVC conduit to an electrical box.
Step 1: Turn the Power Off
Safety is always first. Turn the Power off at the main breaker.
Step 2: Put the Fittings on the PVC
The PVC can be connected to some electrical boxes directly if the fittings are already on the box. Adapters may be needed for threads because the PVC pipe is not threaded. Add the locknuts to the threads.
Step 3: Put the Fittings on the Electrical Box
If the box is not equipped with the fittings, add the fittings to match the connections you added in step 2.
Step 4: Glue and Connect the Pipes to the Box
Once all the fittings are in place, put the cement on the fittings and connect the pipe to the box.
Step 5: Pass the Wires Through the PVC
Once everything is dry, pull the wires through the pipe and the boxes from one end to the other.
Deburr PVC Conduit
When cutting PVC pipe, there are always rough edges left behind. Those rough edges can damage the wire’s insulation on the inside of the pipe. When pulling the cables through the pipe, it can easily rip the sheathing.
Either with rough graded sandpaper or a utility knife, remove all rough edges and shavings. There are several tools you can use for deburring, but nothing works better than a utility knife. It will reassure smooth edges quicker.
Larger Electrical Boxes and PVC Conduit
Many people favor half-inch pipes when working with plumbing or electrical. The best size to use in electrical wiring is 3/4 inch for ample reasons. These are three of the primary reasons to use a 3/4 inch over 1/2 inch conduit.
- There may be a need to pull three or more wires through.
- In the future, you may find the need to pull more wires.
- It is less stressful to pull through a long stretch of 3/4 inch to 1/2 inch.
The same applies to electrical boxes. Single gang electrical boxes are sufficient, but you will need another box if there are two or more sections inside. Male connectors take up the most space inside the box, leaving little space for devices.
Large devices, GFCI receptacles, and dimmers fit better inside 2-1/8 inch boxes.
No Primer Needed for PVC Conduit
White PVC and CPVC pipe require a primer, but not PVC conduit and their fittings. Using the appropriate cement or glue is sufficient, and each application should be measured to avoid dry fittings.
PVC conduit is not like plumbing PVC, where it is easy to pull apart. Once they are shoved in place, it takes a lot of force to remove. Wearing gloves is highly recommended when gluing and putting the PVC and fittings together.
Always keep in mind once the cement is applied, it dries quickly. It only takes a few seconds to dry, so be prepared to move swiftly and accurately. If it dries before you have the fittings in place, it will be more challenging to fit securely.
Advice For Installing PVC Conduit and Electrical Boxes
The best advice to offer is not to get ahead of yourself. Install the PVC conduit and electrical boxes one at a time. It can be tempting to do, but it is easier one run at a time.
If everything is done at once, you will come across a point of problems. It will take bending and fighting the pipe to get it in place. If two boxes are close, it will be that much more challenging.
Space is everything when working with electrical wiring. If there is room to fasten the bushings, nuts, and connectors to the electrical box, the job will move quickly. The PVC conduit will fit right into the connectors.
PVC Conduit with Metal Hangers
It is strongly advised to use metal hangers with PVC conduits. The durability is everything because the plastic ones may give way easily. One screw is enough to hold the metal hangers because the pipe and the wires will be lightweight.
If you are going for looks, use the hangers that offset the PVC conduit. It needs to be the exact measurements as the knockout from the wall on the electrical boxes. For example, a half-inch through a one-inch PVC conduit, the spacing should be three feet apart.
Use a Circular Saw for Cutting PVC Conduit
This is only advice because it is your choice on how you wish to cut PVC conduit. You can use several saws, but a circular saw will make a clean-cut, smooth, and quick. The metal blades will offer less deburring in the end.
The Best Way to Pull Electrical Wires
It can get pretty tricky when pulling the wires through the PVC conduit. If it is a short distance, it is easy, but here is how the pros do it in a list.
- Strip the sheathing about four inches on two of the wires.
- On the two exposed wires, cut off half of the strands for less bulk.
- Take fish tape and loop the wires through the hole.
- Wrap all wires tightly with electrical tape and pull the wires through the PVC conduit.
Use Bushings to Protect the Wires
Even if you deburr the end of the PVC conduit, damage can still take place. The best insurance is cheap, and inspectors love it. Bushings are the added protection for secure and safe wiring to electrical boxes or electrical panels.
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