Electricity can be extremely dangerous; therefore, electrical contractors rely on a number of measures to make it safe. One of these measures is the use of electrical grounding. Electrical grounding involves connecting electrical wiring or devices literally to the ground so that excess electricity (for example, from a lightning strike) can flow into the earth instead of causing harm.
A grounding defect, however, can render the safety measure useless. Below are some of the defects that might affect the electrical grounding in your house.
In the past, grounding connections were connected to plumbing pipes so stray electrical current would flow through the pipes for safe disposal into the ground. This works since plumbing pipes used to be mostly metal, and metals conduct electricity.
The practice is changing due to the use of nonmetal plumbing pipes (such as PVC). However, you can still end up grounding wire connected to plastic pipes due to nonprofessional repairs and installations of plumbing and electrical systems. Such a connection is useless since electricity doesn't flow through plastic materials.
Grounding only works if there is a continuous channel that electricity can follow from the house into the ground. Thus, any discontinuity in the channel renders the whole grounding system useless. An example is a grounding wire connected to a plumbing pipe that is disconnected and is no longer in use. Such a system is dysfunctional since the electricity won't jump the gap into the ground when it reaches the disconnection point.
Short Ground Rod
In a good grounding system, the ground wire is connected to a ground rod — a piece of metal driven deep into the ground. The ground rod provides a convenient way for stray electricity to dissipate into the soil. This won't be the case if the ground wire is merely brushing the ground; it needs to go into the soil.
The grounding wire is one of those things that are most useful in the background; you don't actively use the grounding connections in day-to-day life. That is why it is easy to forget about the grounding system for years. During this time, the connections can corrode, and corrosion increases the resistivity of metals. The corroded grounding connections won't be able to protect you correctly if the need arises since they might fail to handle all the current.
Lastly, the size of the grounding wire also determines its effectiveness. This is because sizes (diameter) of electrical conductors determine their conductivity. If a ground connection is made with an extremely thin wire, the wire might not be able to handle large electrical currents (such as those from lightning strikes).
If you have a grounding defect or other electrical issue, contact a local electrical repair service.