Grounding of circuits is a vital process in circuits. As an electrical engineer, you should understand what grounding means and how to ground a circuit.
Most times, PCB designers and engineers talk about different types of grounds and how to connect them together. However, it is important to understand the principle of grounding and how to ground a circuit.
What is Grounding?
Grounding is when conductive wires which are part of the circuit has a direct path to the earth. Engineers achieve grounding by linking one of the wires to the ground or soil. They run a wire to a ground rod that is directly inserted in the soil. Grounding is very safe and reliable. Without it, the two wires will be hot. Therefore, if someone has physical contact with the conductive part of any of the wire, the person will get exposed to a circuit voltage.
When you ground a circuit, one wire is grounded and the other wire is hot. Circuit grounding offers a lot of benefits. It is crucial in protecting electrical equipment from high voltage. It is a safety measure adopted in all electrical installations and systems. Circuits are grounded to prevent internal wiring failures from increasing the voltage potential of exposed parts.
Grounding offers a circuit return path. Electrical power suppliers ensure one of the wires on their distribution system is grounded. They achieve this by connecting this wire to the ground. In a proper grounding, circuits must have a return path which is from the electrical equipment to the source of power.
The types of grounding are earth ground, safety ground, digital ground, analog ground, and chassis ground. For a grounding to be properly done, there should be electrical connections between metallic components in order to avoid a voltage connection from these components. Also, there has to be a zero voltage and low resistance to short circuit a breaker when there is an electrical fault.
What is Earth Ground?
Earth ground is a ground that connects to earth through conductive materials like aluminum or copper. It comprises a conductive rod or pipe drive in the earth within 8 feet minimum depth.
The earth is protected from electrical wavering due to its state of neutrality. However, this is a generalization as the electrical capability of the earth experiences some isolation due to events like hits and lighting.
How Does Grounding Work in a Circuit?
Electrical circuits have three different wires. These are hot wire, grounding wire and neutral wire. The hot wire contains an active voltage which is responsible for powering electrical fixtures. One thing about an active voltage is that it has a negative charge. Electricity that is negatively charged looks for ways to get its negative energy discharged in order to get back to its neutral ground.
Therefore, the negatively-charged electricity goes through the neutral wire and goes back to the positive charge of the main service panel. In this case, there is flow of negative charges through the hot wire when circuits remain complete. These negative charges go back to ground via the neutral wire. The grounding wire isn’t needed when everything works perfectly.
Sometimes, circuits can malfunction or experience failure. In this case, electricity could flow out of the system and interact with other materials when wires are damaged. The current could shock you or cause a fire. However, this depends on the flow of the current. Therefore, it is of utmost importance to ground wires. Grounding wires can prevent a lot of damage from occurring.
Voltage always seeks neutrality and as such, it goes through the path of small resistance when it is no longer in the closed-circuit system. When voltage strays from the electrical system, the grounded wires capture it and send it to the ground where it is harmless.
Why is Grounding Important?
Grounding a circuit is a safety procedure that needs to be implemented. It offers protection to humans and their environments. This could be a prevention from dangers associated with electrical overloads and damaged circuits. When there is a high surge in power, the excess electricity in this system could flow out. This stray voltage can cause damage or fire. Also, it could shock you.
Grounding also makes it easy to distribute the appropriate amount of power. It prevents circuits from experiencing overloading. The earth is a reference point for the sources of voltage in the system. Grounding provides a stabilized level of voltage all through the electric system.
In scenarios where there is a power surge, circuit grounding protects the electrical system in your home. Lighting strikes are bound to occur. When they occur, they could cause damage to electrical appliances. Grounding can prevent that from happening. Also, it prevents arcing of voltage to conductive materials.
Improper grounding or not grounding at all could put you at risk. Sometimes, high electricity goes through a device, this device can get damaged if there is no proper grounding. Too much electricity flow can cause a device to catch fire. Earth is a good conductor of electricity. With least resistance, the earth is capable of conducting all excess electricity.
However, grounding a circuit indicates that the excess electricity can move to somewhere else instead of passing through your appliances.
How Do you know if Circuits are Grounded?
Most times, you can only detect proper grounding by inspection or using a circuit tester. There are certain things you can check if you need to be sure if your circuits are grounded. You need to be sure if an outlet has two or three prongs. The third prong in an outlet ensures connection to the ground wire. When you notice two prongs in your outlets, this means the circuits are not grounded.
Sometimes, your electrical outlets may have three prongs and lack proper grounding. Some homes have improper grounding due to wiring errors or damage. In this case, you need to hire a professional inspector or purchase a home circuit tester. These two ways can help you detect proper grounding in your outlets.
Note that electrical circuit grounding is completely different from electrical equipment grounding. In electrical equipment grounding, a third wire is run to a device and then connected to the third prong of an outlet. The best way to check for grounding in electrical equipment is to be sure if the equipment has a three-pronged plug and a three-wire cord. The third prong and third wire will offer the ground connection between the grounding of the wire and the frame of the electrical equipment.
How to Carry out Electrical Grounding Test
You can always carry out an electrical grounding test to be sure of proper grounding and the safety of your electrical circuits.
- Check your outlet for three prongs with a U-shaped slot.
- Put the circuit tester’s red probe in the smaller part of the outlet. The outlet functions as a power supply to your electrical appliance.
- There is black probe you can insert in the larger slot of the outlet. This will help you complete the circuit.
- An indicator light will show up if the outlet is properly grounded. If otherwise, reverse the two probes. If the indicator light doesn’t still come up in this test, this means the outlet has no grounding.
Importance of Built-in Protection in Appliances
The wiring system in homes often contains some safety devices that could prevent the occurrence of disaster. For instance, devices like fuses or circuit breakers can regulate and protect each circuit. Fuses or breakers serve two major purposes. They prevent overheating from occurring in wires in cases where there is an overload due to too much current drawn via them.
Furthermore, circuit breakers or fuses detect short circuits and immediately prevent current flow when this happens. When there is a short circuit, there is an instant decrease in resistance which leads to current flow. Therefore, the circuit breaker prevents this by tripping.
Homes have metal plumbing pipes which are usually linked to the grounding pathway. With this, there is extra protection when metal pipes have contact with electricity. This type of grounding can be performed when a grounding wire clamps to a metal water pipe.
There are several plug-in devices that feature a grounding system. Vacuums and power tools offer more safety when there is a third prong. The third prong reveals there is a grounding system in the electrical appliance. Sometimes, a grounded outlet isn’t available. In such cases, you can install some protection like a GFCI known as ground-fault circuit interrupter.
GFCI can detect ground faults and stop power before more problems arise from straying current. Using a GFCI only makes it safer to use an ungrounded outlet. Therefore, a GFCI won’t offer a grounding pathway.
Conclusion
Grounding is a common process usually carried out in engineering. Having read this article, readers should understand how to ground a circuit, how it works, and its importance in electrical appliances. Grounding uses wires to direct excess flow of electricity to the ground. The wire used in this process is a grounding wire. This wire gets rid of excess electricity by transferring it safely to the ground.
