There is a lot of confusion about grounding and bonding and the purpose of each. We talk about grounded electrical outlets, ungrounded outlets, ground rods, bonding, etc. Sometimes, the words “grounding” and “bonding” are used interchangeably, but they mean different things and they serve two different purposes. So, what is the difference between grounding and bonding? Let’s start with the definition of each one. Since I am a home inspector, I am going to discuss these terms only in regards to a home’s electrical system, and will not get into a discussion of the industrial uses of grounding and bonding.
What is Grounding?
Grounding is connecting your home’s electrical system to earth in a manner that will limit the voltage caused by lightning, line surges, or unintentional contact with higher-voltage lines, and that will stabilize the voltage to earth during normal operation.
Put another way, the purpose of grounding is to maintain a constant voltage of your home’s electrical system by dissipating voltage spikes caused by outside influences such as a lightning strike or a voltage spike on the transmission lines. The reason you don’t want voltage spikes on your home’s electrical system is because voltage spikes or surges can damage electrical equipment/components in your home.
Grounding is normally accomplished by connecting the electrical service of your home to a ground rod. This ground rod is normally an 8-foot long solid copper rod that is driven into the ground. This provides a path for any voltage spikes to travel to and dissipate into the ground.