MIN. SIZE OF EQUIPMENT GROUNDING CONDUCTORS (EGC) for Grounding Raceway & Equipment

In other words, the size of the equipment grounding conductor is based upon the rating or setting of automatic overcurrent protective device in the circuit ahead of the electrical appliance or equipment. The equipment grounding conductor based on Table 250-122 for the 50-ampere range circuit is a No. 10 copper or No.

For example, if you have 100 amps from step 1, your grounding conductor size should be eight gauge wire or eight AWG.

According to Table 250-122, the minimum size equipment grounding conductor permitted with a 40-ampere overcurrent device is No. 10 copper, but Section 250-122(a) says that the equipment grounding conductor does not have to be larger than the circuit conductors.

50 AMP Wire Size For a maximum of 50 amps, you’ll need a wire gauge of 6. Fifty amp breakers are most often used to power many different appliances. However, a kitchen oven can alone require 50 amps. Many electric dryers also require a 50 amp breaker.

So the 16 gauge wire is perfect for grounding. 14 gauge is generally used for circuits that have a maximum of 25 amps going through circuits. 20 amp breakers tend to need the 12 gauge copper wire for grounding. For example, GFCI outlets should use 12 gauge.

The negative conductor carries the same current as the positive conductor and so must be of the same size. As long as the wire is a good conductor, electric current will flow when there is a closed circuit.

Unfortunately, size does matter. The most basic explanation on why wire gauge matters is because the thinner a wire is (higher gauge) the more resistance there will be to the flow of current. The amount of copper in wire roughly doubles when comparing wires 3 gauges apart.

Recognize that the black wire is the positive one, the white wire is the negative one, and the green wire is the ground.

A DC cable only has to resist the steady measured DC voltage and therefore has a certain thickness. An AC cable of the same nominal voltage, has to resist peak to peak voltage, which is about 1.414 times the equivalent DC voltage. Therefore, I would assume its insulation would be thicker.

The moving electrons can collide with the ions in the metal. This makes it more difficult for the current to flow, and causes resistance. The resistance of a thin wire is greater than the resistance of a thick wire because a thin wire has fewer electrons to carry the current.

Of course you can use but it is subjected to increased losses. For DC, current distribution is uniform in all over cross section of cable so electrical cross-section = physical cross-section. For AC, current distribution is non uniform due to the time varying nature of magnetic flux produces.

DC resistances are given. And the solid wire has lower resistance than stranded. So solid is better for DC although the difference is neglible.

Don’t use solid wire for 12v systems, electrical current is carried along the surface of the wire not the inside, that’s why heavy amp draw wiring use multi-strand wiring, the more strands the better the current carrying surfaces without heating up.