Setting An Earth Ground & Benefits

 Setting An Earth Ground & Benefits

An electrical point known as ground or earth is the point of reflow for current or reference measurement for the voltage (0 volts), also known as potential difference. The ground in any electrical setup serves many purposes, e.g. static charges are built up, and they need to be removed. Else could lead to severe damage to electrostatic-sensitive devices. The ground is placed inside the earth via a metal rod, which prevents shock hazards if there are any areas not properly insulated. In the case of remote appliances or handheld devices, the ground is more appropriately known as ‘common’, in which all paths are returned to a common point that acts as a ground.

We can here classify ground as the in-circuit ground also termed as Analog-Digital ground and the earthing ground. Its name suggests that it is placed inside the earth via a metal, usually copper. The in-circuit ground is connected to the device's chassis and is then connected to the earth's ground (external).

Figure 1 Earth Ground Setup

Setting Up An Earth-Ground:

Usually, two wires complete the circuit, one is the alive or hot wire which carries the current, and the other one is a neutral wire which completes the circuit. These two wires run from a socket plug to the main and then to the transformer. However, there is another wire which is the earth wire. The appliances have earth wire attached to the chassis via running through the neutral wire and complete the internal circuit. When these appliances are plugged into the socket, the connection is established, and in case if there is any short, the earth-ground wire makes the path to the earth and prevents the shock. The earth wire is connected to the ground rod, which is a metal and is buried into the ground. Since the ground has such a large volume, the spikes or charges developed during the short are submerged into the soil without making much of a difference, keeping the devices safe.

Figure 2 Earthing Resistance Nominal Values

Soil resistance is of the utmost importance when setting up earthing for domestic or industrial usage. A lower resistance value is preferred since it projects minimum resistance to the current flow. Hence the selection of low resistance electrode which matches the earthing or soil ohmic resistance is needed. Here one thigs also needs to be kept in mind while designing that the upper layer of earth changes in terms of moisture and temperature due to seasonal effects, so the rod must be buried deep into the soil where the temperature and moisture levels are much stable. The nominal values shown in figure 2 are calculated depending on how many rods are installed and the distance between the rods however the basic calculation is done using ohmic resistance law, which is R (Ohms) = VI.

Pros Of Having Earth-Ground:

·         Provides A Reference Voltage Level Against The Other Voltage Levels In The System.

·         Prevents The Electrostatic Build-Up Effect.

·         Helps Prevent The Lightning Effects.