What's happens when I flick the light switch?
When you think of the electrical wiring system of a house, you might know it consists of wires and circuits. These wires and circuits provide a 360-degree delivery of electricity from the main electrical panel to an outlet, or series of outlets that service appliances, and then flows back to the panel. The electric circuits in a standard house electrical wiring system in the United States is generally comprised of 120-volts or 240-volts.
House electrical wiring in the United States is governed by the National Electrical Code (NEC), which is published by the National Fire Protection Association (NFPA 70). As an example, the current code dictates that three-pronged, polarized receptacles are to be used in all new home construction, in addition to, outlining the use of ground fault interrupters (GFI) in locations where an electrical appliance may be subjected to moisture.
The standard household electrical outlet consists of two three-pronged, polarized receptacles. Each receptacle has a 120-volt ‘hot’ wire, a neutral wire and a ground. This dual design allows the use of either hot wire to supply the standard 120-volt household circuits. For higher power applications like clothes dryers, electric ranges and air conditioners, a single receptacle is used where two of the prongs are a hot wire and the third a neutral, which can be used to produce a 240-volt circuit.
The two receptacles in a common outlet receive power from the same circuit leading from the main electrical supply panel. They are wired together so that two appliances which are plugged into the receptacle receive the same voltage, but can draw different amounts of electric current. This parallel wiring is the standard for 120-volt circuits in the entire house, making possible the independent use of all appliances, supplied by the same voltage.
The wider prong on the polarized plug will permit it to be plugged in only with the correct polarity. The narrower prong is the ‘hot’ lead and the switch to the appliance is placed in that lead, guaranteeing that no voltage will reach the appliance when it is switched off.
Interruptions in circuit wiring are not only an inconvenience, but also present fire hazards. The Consumer Product Safety Commission estimates that 50 people die every year from accidental electrocutions involving residential wiring, panel boards, circuit breakers, and outlets. Another 40 electrocutions each year involve household appliances that are connected to the wiring of homes.
By making sure you have a thorough electrical inspection completed by a qualified Mister Sparky ® electrician before buying, selling or remodeling a home, you can help ensure your home's electrical system operates at the highest level of safety possible. Our trained technicians can provide whole house re-wiring and evaluation of your circuits to ensure the safe delivery of electrical current within your home.