This is not an issue with grounding electrode conductors put in PVC conduit or other nonferrous metal raceways like aluminum or brass conduit. PVC conduit is not always permitted due to the kind of construction. For example, if it's only rated for wet conditions, then it can't be used as a grounding conductor for electrical systems that might experience water damage.
The most common way to ground a system is through the use of buried conductive rods called leach pads or grates. These are required by law in some areas and often include portions within concrete slabs or under asphalt. The conduit used as a ground wire should be either black or white when used as a grounding conductor.
Conduit is a very convenient way to run ground wires because they can be easily accessed without having to break any surface coverings-for example, if you need to make repairs or add circuits later on.
Not only does this save time and money, but it also protects environmental resources by reducing the amount of digging that needs to be done.
Grounding conductors are also necessary in multiple conductor cables such as RCD (rated circuit breaker) feeds and hot-walled cable runs. In these cases, each conductor must have its own separate path to ground to prevent current from flowing through the body of the cable.
PVC is not conductive, and therefore cannot be utilized as a grounding medium. Metallic conduits are grounded because all metallic elements of the electrical system or appliance must be grounded when appropriate. This includes metal pipes inside walls, floors, and ceilings as well as metal wiring inside appliances.
The only time PVC should be used as a ground conductor is if it is part of a complete ground fault circuit interrupter (GFCI) protected extension cord or power strip. In this case, the plastic sheath of the cable can function as a ground.
In other words, you can use PVC piping as a protective barrier against electrical damage to your property, but you cannot use it as a conducting path for current flow.
Is a ground wire required in PVC conduit? In most cases, the metallic conduit will also contain an earth wire. However, if you are installing a new circuit to an existing house with metal siding or a metal roof, then you should also connect the conduit to the metal structure. This will fulfill the requirement for a conductive path back to metal.
If you are working with aluminum or steel conduit, then you do not need to worry about a ground wire because these materials are always considered ground-fault protected. This means that if any part of the conduit body becomes energized (hot), the electricity will automatically find its way into the surrounding soil via the copper pipe and into your body via your feet.
The only time you would need a ground wire in aluminum or steel conduit is if you were trying to connect two different sub-circuits together. For example, if there was an outlet in the middle of the room and another outlet next to it but on another branch off of the main circuit, you would need to provide a ground connection between these two branches. Otherwise, you could get a shock when you tried to use them simultaneously.
It is OK to run bare ground within the PVC conduit. Inside is preferable to outside because if you ever need to service it or if demand rises out there, you can draw additional conductors and a larger ground. These things will affect the inner wires too but that's why they're protected by insulation. If you put them outside then you're just gambling that nobody will touch them.
The best way to go is with 2 conductors in parallel spaced far enough apart so they won't interfere with each other's ability to carry current. Then add another conductor for earth bonding/grounding. This becomes known as a 3-wire system. If you use 4 conductors then at least 1 of them can be used for lighting which makes this a 4-wire system.
It's important to remember that even though you can run a bare ground inside PVC conduit, this does not mean that you have to. The main reason people do this is because it saves time during construction when you don't have to separately punch down conduits to serve as grounds. But if you have to work inside the conduit sometimes then it's better to run unprotected wires than a bare ground because you can always pull them up after working around them.
The other option is to bury the cable.
PVC is a highly corrosion-resistant polymer that does not degrade in corrosive situations such as salt water or chemical exposure. The disadvantage of PVC is that, being a non-metal conduit, it lacks grounding qualities. In order to remedy this, electricians install an additional grounding wire in all PVC pipes. Corrosion can also be prevented by using anti-corrosion additives during the manufacturing process.
Metal conduit is made from aluminum alloy or steel and can withstand harsh conditions with little to no damage. Conduit is available in various sizes and shapes for different applications. Metal conduit is considered to be more affordable than PVC but it is also heavier which may not be desirable for certain applications.
Both types of conduit are acceptable for use under the National Electrical Code. It depends on what type of installation is required most heavily weighed against each other's advantages and disadvantages.
Although I believe it is best practice to always supply a ground wire inside metal conduit, there are likely millions of installations that rely on metal conduit as the path back to the service equipment. This is seldom an issue as long as neutrals and grounds are not bound together in the sub-panel. If they are bonded together, then they must be taken together when entering metal conduit.
If you're following all the other rules but this one, there's no problem using a ground wire inside metal conduit. It can be done, but it's not recommended because it makes servicing the system more difficult if not impossible. Metal conduit is designed to carry live current and should never have any portion of it exposed or unprotected. If some part of the conduit body is exposed, it must be covered up with some kind of non-metallic material such as plastic or rubber.
The reason this isn't recommended is because if you need to reach into the conduit to work on something by mistake, you could get burned by the electricity. Even if the metal conduit is empty, it can still cause serious injury or death if it's touched by someone who doesn't know how to handle it safely. Grounding the conduit will prevent this from happening.
Besides being dangerous, running a ground wire inside metal conduit is unnecessary because if there is no load present, there is no need for a ground connection.
PVC conduits are also employed in situations where electric wires must run beneath the earth or in an open environment exposed to air, dust, and water. Electrical metal conduits are ideal for applications in the basement or garage, where wire often runs down the surface of the wall. They can also be used when working with electricity is not an option, such as during earthquakes.
Electrical metal conduit is manufactured from aluminum or steel and is designed to provide electrical protection and a return path for electronic equipment power cords. The size of electrical metal conduit needed depends on the length of the project and the type of material used. Conduit is available in various sizes from 2 inches up to 12 inches. For example, if you were building a house and wanted to put electrical wiring in the walls, you would need electrical metal conduit. The conduit should be long enough to reach from the basement to the attic and back again.
The type of conduit used should match the application. If you were running cable, for example, you would use RG-6 or RG-8 cable conduit. If you were using EMT, you would use EMT conduit. Keep in mind that the conduit has to be able to handle the load; if it's not right for the job, find another one that is. You don't want to have to replace your conduit just because it's old or damaged.
Conduit is available in two types: metal and plastic.