This drawing shows the wiring for adding a new light fixture using an always-hot receptacle outlet as the source. New cable is run from the receptacle to the new fixture location and a switch loop cable is run from there to the new switch location.
This arrangement is used for computers and sensitive A/V equipment such as a home theater, to eliminate noise interference in the audio and video output that can be caused by the grounding wires throughout a dwelling’s electrical system.
This is an updated diagram for the same circuit. Here the source neutral, known as a grounded neutral, is run through to the switch box where it can be used to power switches that require a neutral connection. A neutral connection like this is now required in most new switch boxes as of the code changes in 2011.
An isolated-ground receptacle makes use of an extra wire for a separate ground in the circuit. This is the red wire in the 14/3 cable used here which is marked and connected to the grounding terminal on the receptacle. The other cable wires are connected as with any other circuit except for the ground wire. The bare copper ground wire is NOT connected to the receptacle, instead it is connected to the grounding terminal inside the electrical box where the receptacle is housed.
If you’re installing a new doorbell, a remote controlled device makes for the simplest installation and doesn’t require any of the circuitry illustrated on this page. All that’s required is to mount the button near an exterior door and the chimes in a convenient, central location inside the house. No need to run wires or splice into household circuits, fresh batteries are all that’s required.
This type of switch will be referred to as a 2 circuit lamp switch when shopping at home stores. Don’t mistake this for a three way switch (pictured below), the two do not function in the same way.
This diagram illustrates the arrangement for a 20 amp double receptacle circuit with a shared neutral wire. This arrangement is typically used in a kitchen where two appliance circuits are needed in close proximity to each other.
These sockets have two terminals, one for the hot wire and one for the neutral. A third contact may be present but is not used for this circuit. This diagram illustrates wiring for a standard, one setting lamp. This socket has two terminals, the brass for hot and the silver for the neutral wire.