The grounding conductor can be greater than the minimal required, but it cannot be smaller. In fact, the neutral wire does not necessarily have to be the same size as the "hot" or ungrounded wire, and the ground wire is occasionally more than one size smaller. In summary, ground wire is primarily intended for life protection. It should be large enough to reach any appliance that may pose a risk of electrical shock if not connected.
The amount of current that a ground wire can safely carry is dependent on how far it has to go from a source under normal conditions. The farther it has to go, the less current it can handle. A good rule of thumb is that the ground wire can carry no more than 1/2 the number rating of the other wires. For example, if your house is wired with 20-gauge wire, then the ground wire cannot be thinner than 14-gauge.
When you connect a ground rod to the wiring system, it becomes part of the ground path. Therefore, the ground rod needs to be able to carry current too. Otherwise, you might be creating a dangerous situation where there is no ground path from house to hole.
The ground rod should be located near the foundation in an area where it will stay put. This means that it shouldn't be buried very deep. If you do have to drive it deeper into the soil, then it should be driven at least 3 feet into fresh dirt.
The minimum size for a grounding conductor for a circuit protected by a 200-amp breaker, according to Article 250 of the NEC, is #6 copper or #4 aluminum. This conductor's size may need to be raised for a variety of reasons, including the length of the run, available fault current, and other factors that would fill a book. But if you have 100 feet or more of exposed metal between your house and the next-door neighbor's, you should check with an electrician about what size wire you need.
If you're using stranded conductors instead of solid ones, each strand needs to be at least as large as any other strand in the cable. For example, if one strand is twice as large as others, it must be at least 3/0 wire.
Grounding conductors are required by law to supply at least one conductor for every circuit brought into the home. If there are no load terminals on the subpanel, such as with a meter base or a water heater panel, then the grounding electrode will connect the subpanel to the structure of the building through the chassis of the meter or water heater, respectively. The presence of a third path out of the panel ensures that someone can connect a wire to the ground pin if another conductor within the panel breaks.
Subpanels are used in industrial settings to distribute power from larger panels located near heavy equipment. These smaller panels allow for more efficient use of space than distributing electricity from one large panel.
A ground wire's purpose is to provide a safe path for surplus electrical charges. Because the solid mass of earth beneath our feet contains a negative electrical charge, it is naturally drawn to positive electrical charges. Thus, a ground wire allows electricity to flow safely away from objects that are positive (such as metal appliances) and towards earth, which is always considered neutral in electricity.
Grounding yourself is very important if you are working with electricity. It prevents your body from becoming a complete conductor of electricity, which could be dangerous. When you touch a metal object, some of that energy will travel through you and into the ground. If you aren't connected to something else, this current will find its way back to where it came from and enter your body through your foot or hand. This is why it is important to know how to ground yourself before working on an electrical project.
The easiest way to ground yourself is by touching an appliance that is also connected to earth. For example, if you were using a lamp and it had a built-in ground, you would not have to worry about getting shocked because it would take the current from the lamp into the ground instead of into you.
It is recommended that you connect any other grounded objects to your body, such as a plumbing pipe or metal fence.
The ground wire has no length restrictions; any suitable length is acceptable. The ground wire should be able to reach all potential ground locations. For example, if you have metal stairs that go down to an underground parking garage, then the ground wire needs to be long enough to connect to the metal railing on each step.
If the wiring system was done properly, there should be only one connection to the electrical panel, and that's called a "grounded conductor." This is the wire that connects to the metal railing on each step if you're using them as grounds. If you're not using any parts of the building as grounds, you don't need to run a separate ground wire. Just make sure the black wire in your cable is always connected to something good!
The reason we need to connect our ground wires together is because electricity is transmitted by way of electrons, which are negative charges. These electrons want to stay where they're atrapped by atoms with positive charges, so they want somewhere for these charges to go when they move around inside of objects. That place is called a "ground," and it provides electrons to take their place.