Are you thinking about buying your home’s electrical cables underground? You need a conduit, and PVC conduits are a decent option. But what if you don’t have any PVC conduits on hand? Can you use ordinary plumbing PVC pipes instead? Yes, but as this guide is about to show, the practice is risky.
Can PVC Be Used For Electrical Conduit?
I don’t suggest using PVC for electrical conduit because
- They cannot offer the protection that electrical conductors require, not in the long term. You cannot trust them to resist and repel corrosive elements. Additionally, if PVC pipes catch fire, they are more like to emit toxic fumes.
- Wires can’t fit inside a PVC pipe. People measure PVC pipes on the outside. On the other hand, they measure PVC conduits on the inside. Therefore, even though PVC pipes and conduits have the same external diameter, their internal measurements may vary. You could damage the cables by forcing them to pass through a small PVC pipe.
If the differences don’t concern you, consider the fact that the NEC frowns upon this practice. The local code in most places is just as strict. If you install PVC pipes in a commercial location, you may incur hefty fines.
This question won’t make any sense to you if you use PVC conduits all the time.
After all, polyvinylchloride is an excellent material for tubes. The people at PPFA use it in their conduits and ducts because it is self-extinguishing, low maintenance, and impact resistant.
Additionally, it is non-magnetic and resistant to chemicals. Contractors use PVC in bridges, subways, waste treatment plants, marinas, mines, airports, etc. You will find the material in data and lighting projects.
PVC has very few rivals because it has a litany of appealing features. As such, you may wonder why anyone would question the viability of PVC as a material in an electrical conduit.
However, the question above has nothing to do with electrical PVC conduits. While electrical contractors associated PVC with electrical conduits, plumbers use the material in pipes.
They are both made from PVC, and the layperson may confuse them for one another. However, PVC pipes and PVC conduits are not the same.
Electrical PVC is gray. On the other hand, PVC pipes are white.
This leads back to the first question. Can you use PVC pipes as electrical conduits? Yes, you can. However, manufacturers do not make PVC pipes with electrical wires in mind.
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What Kind of PVC Is Used For Electrical Conduits?
You have to use gray PVC for electrical conduits, not white PVC.
PVC conduits are made from polyvinyl chloride, which combines vinyl and plastic. PVC pipes use the same material. But PVC conduits are different because they have couplings, elbows, connectors, and fittings that users can attach with glue.
The Spruce expects consumers to provide proper grounding at the connection points by running a green wire through the conduit. You can install PVC conduits underground, inside walls, and on exposed surfaces. PVC conduits protect the cables from pests like rats.
On the surface, PVC conduits look like PVC pipes. However, the conduits are gray instead of white. More importantly, conduits have thinner walls than their plumbing counterparts.
If you think about it, the difference in thickness makes sense. Yes, PVC conduits have to protect delicate wires. However, people expect the pipes to carry water at a relatively high pressure, which is why the walls are so thick.
Therefore, it isn’t just a question of whether or not a PVC pipe can work as a PVC conduit by protecting electrical wires. You cannot use a PVC conduit as a PVC pipe. It cannot withstand the pressure.
Pay attention to the color. It is the most distinct feature.
Can Schedule 40 PVC Be Used For Electrical Conduit?
You can use schedule 40 PVC for electrical conduits because it is wider on the inside. Therefore, you will have an easier time pulling wires through a schedule 40 PVC conduit.
Technically speaking, schedules 40 and 80 are the size. But schedule 80 is stronger because it has thicker walls.
But as a result, schedule 80 conduits have a smaller interior. People who use them do not mind because the thick walls enable the tubes to withstand higher pressure.
Note: You must select the gray schedule 40 PVC. White schedule 40 PVC works in plumbing.
When To Use Schedule 40 VS 80 Electrical Conduit?
The term ‘Schedule’ in relation to conduits has nothing to do with the English definition of that word. It refers to the thickness of the walls.
- On the surface, schedules 40 and 80 are the same because they have matching diameters. But that is only true for the exterior.
- On the inside, schedule 80 is smaller because it has thicker walls. This encourages consumers to conclude that schedule 40 works in low water pressure situations while schedule 80 thrives in higher water pressure settings. And that is true.
Contractors that install conduits in residential settings rarely consider the amount of pressure the tube can withstand. Does that mean schedules 40 and 80 perform the same role in electrical settings?
The thick walls you find in a schedule 80 PVC conduit matter to electricians. They use these tubes in rugged locations that expose conduits to extreme conditions.
You will find schedule 40 in the walls, ceilings, and floors. I don’t want you to expose these conduits to physical abuse. Their walls are not strong enough to survive strenuous conditions. You can bury them underground. They can even survive in concrete. Schedule 40 is still a conduit. It can withstand elements like direct sunlight that typically ruin wires. But it isn’t as strong as schedule 80.
If you have to choose between the two, schedule 40 is more than adequate for a residential setting. Schedule 80 might be stronger, but it also costs more money. As such, contractors avoid it unless they have to install conduits in industrial environments.
NEC Code For PVC Conduits
NEC allows contractors to use PVC conduits. They include the following:
- You can use the material on walls, floors, and ceilings
- You can install them in places that expose the conduits to corrosive elements
- You can use PVC in wet locations, including laundries and dairies
- You can use PVC in areas that expose the tube to physical damage
- You can install PVC conduits underground
- You can expose PVC to temperatures that exceed the conduit’s temperature rating
On the other hand, you have to keep PVC away from temperatures over 122 degrees F. Avoid theaters and hazardous locations. It is also unwise to use PVC for the support of luminaires.
Code Library has a more comprehensive list of instructions. They explain all the circumstances in which the NEC permits or prohibits the use of PVC conduits.
Naturally, you have to check with your local code before you proceed. The local code many contradict the NEC’s advice on PVC conduits. If that is the case, listen to the local code.
Most states tend to agree with the NEC. They use the NEC’s regulations to guide the contractors in their jurisdiction. But there are plenty of exceptions, which is why professional contractors keep a copy of the local code on hand, just in case they need to refer to it.
PVC Electrical Conduit Sizes
NEC wants consumers to avoid PVC conduits smaller than 16 (trade size ½) or larger than 155 (trade size 6).
Is It Affordable?
PVC conduits are the cheapest and lightest. AK Electrical Services believes that half an inch of PVC (10-foot partitions) will cost you $2.10.
Pros and Cons of Using PVC For Electrical Conduits
1). May Withstand High Pressure
PVC pipes are designed to withstand significant water pressure. The same cannot be said for PVC conduits. The factor doesn’t prevent the pipes from carrying electrical wires. But it prohibits contractors from using the conduits to carry water.
2). Resist Bending
Pipes can withstand higher pressure because they have thicker walls. On the one hand, this is a good thing because you can trust the PVC pipe to protect your wires from destructive elements. On the other hand, PVC pipes are less flexible. They resist bending.
3). More Resistant To Electrical Wires
PVC conduits are supposed to be better than pipes because they are more resistant to elements that harm electrical wires. However, Hunker has noted that some PVC pipes have chemical components that allow them to resist corrosion, fire, and high temperatures.
This is why some PVC pipes can work as conduits, but you can’t use conduits to carry water.
4). Sunlight Can Ruin Them
One of the most significant disadvantages of a PVC pipe is its weakness in the sun. Conduits cannot withstand high pressure because manufacturers do not see the point in making them so thick that they can resist high pressure.
They apply the same rationale to pipes. PVC pipes are normally out of sight. Contractors bury them underground or install them indoors. They rarely see the sunlight.
For that reason, direct sunlight can ruin them. Ultraviolet rays make the pipes brittle, creating cracks. This is why you shouldn’t be so quick to replace conduits with pipes, even though they have thick walls that can withstand a lot of pressure.
Manufacturers have armed PVC conduits with all the tools they need to resist the side effects of direct exposure to ultraviolet rays. They can survive out in the open for a long time.
This is not your only concern. Plumbers know what PVC pipes look like. Unless you add a label informing newcomers that the pipes have electrical wires, a plumber may cut your PVC pipes open.