You might have wondered about the third prong on an electrical plug. If you didn’t know, the third prong on plug is the ground connector. It is round and just under the two blade-style plug protrusions. It is a critical piece included with outdoor extension cords and also on any device that is not fully shielded. You can think of it as an emergency path for electricity to travel through if a short circuit or other fault develops inside the electrical device.

How the Third Prong on a Plug Works


Inside all appliances that have plugs are wires and other electrical components that can potentially break off or dislodge. Household current has the capability of killing a human being. A tiny wire or other component that is carrying household current can come loose and charge the outer case or metal connectors of an electrical appliance. If the device is not grounded, it is highly likely that the next person who touches the device will receive a potentially lethal electric shock. If a grounding circuit is present and intact, the electricity flows along the ground and trips the breaker or blows a fuse, which halts the power supply.

Is It Safe to Cut the Ground Prong or Use an Adapter?


All three-prong plugs must be connected to electrical receptacles that can receive a three-pronged plug. Also, the electrical receptacle itself must have a ground circuit connected internally that goes back to the main service panel. When you plug in a three-pronged plug, that third prong is providing an alternate pathway for electricity in the event of a fault. If you cut the third prong off of a plug, you defeat the safety feature. Also, adapters were designed to use the cover screw to complete a ground circuit on some older plug designs. However, some older plugs do not have an internally connected ground, and many people never actually connect the screw properly to a three-to-two prong adapter.

Why Do Some Plugs Have Three Prongs and Some Do Not?


Electronic devices that connect using a voltage adapter that lowers the household current before it gets to the device do not have lethal voltage. Think laptop computers and game consoles that connect to a transformer brick or power adapter. Other devices may be shielded using plastic cases and other insulators to prevent short circuits from electrically charging their outer cases or shells. However, water intrusion and other things can cause a potential for a lethal shock in a shielded device. All electrical appliances designed for outdoor and wet area use should have a third prong ground on the plug and be connected to a ground fault circuit interrupter (GFCI) receptacle.

Contact Mister Sparky® of Clearwater for Expert Electrical Advice


If you have any questions about whether or not your electrical receptacles have proper grounding capability or if you need help in converting older two-prong receptacles to modern three-prong ones with grounds, please give Mr. Sparky a call today to schedule a service appointment.