Electrical appliances are manufactured using internal components that become electrified when in use and need to be isolated from the user. Since the casing or external metal parts are connected to a ground wire, it creates a safe path for any fault current to be transferred away from the user.
This type of grounding is also found in most manufacturing facilities and also prevents static charges from accumulating and affecting their process.
The wiring in your home should have its grounded circuits connected to the main building ground. This can be either the water main or piping system, or a dedicated ground rod or plate. Clean and solid connections are required to assure a solid path to earth and should be checked after any building or electrical modifications to assure your home’s safety.
Although supply side surges or strikes during thunderstorms will also be reduced to some extent whole house surge protection is by far the best way to protect your electronics from these abnormal power situations. Surge protectors will only work if connected to a grounded connection. In order to offer your expensive electronics and appliances the best protection, make sure that you are plugging them into a properly grounded electrical system.
The ground-fault circuit interrupter (GFCI) is another layer of protection that is extremely delicate and is capable of detecting leaks as small as 5 milliamperes. After detecting leakages, the interrupter immediately disconnects any circuit from the source.
Although circuit breakers and fuses provide overload or overcurrent protection for the device, tool or appliance connected to the circuit, they do not provide the personal protection needed to safely direct stray power to ground.
There are far too many risks to having an electrical wiring system that is either improperly grounded, or not grounded at all. If you live in an older home, your system may not be grounded at all. Even in newer homes, your system should be checked to be sure the electrical system is properly grounded. All it takes is a few bad connections to render a grounded system completely ineffective.