A good ground connection is essential to the safe and reliable operation of any piece of electrical equipment.
Electrical grounding ensures that if there is ever a short circuit on a piece of electrical equipment, current will flow through the ground system and trip a breaker or blow a fuse.
A grounded outlet has three holes for each plug. In a properly wired outlet, the rounded slot is the ground connection.
A grounded outlet must be used correctly to provide good protection:
Never cut off the third grounding prong on an appliance plug.
Don't try to install a grounded outlet in an ungrounded receptacle.
Use "cheater" adapter plugs only on a temporary basis. When using these devices, make sure the small metal circle on the bottom contacts the screw in the middle of the outlet.