This diagram illustrates wiring for a circuit breaker with a built-in ground fault circuit interrupter. This 20 amp ground fault interrupter breaker is a form of gfci that can be installed at the circuit source. This kind of circuit is used for dishwashers, whirlpool spas and other locations where water contact is likely.
With this lamp, bulb A can be turned off and on independently and switch B can turn on bulb 1 alone, bulbs 2 and 3 together with bulb 1 off, bulbs 1, 2 and 3 all on at the same time or all three off.
Here 3-wire cable serves a split receptacle. The bottom half of the receptacle is controlled by a switch and the top half is always-hot.
A special isolated-ground receptacle is require for this circuit and can be identified by the orange color and a small triangle imprinted on the face. When connecting the wires, the isolated ground wire (the red wire pictured here) is marked with green tape or paint on each end and connected to the grounding bar in the service panel, and to the grounding terminal on the receptacle.
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.
The battery is the weakest link here and should be the first place to look for trouble. The battery can be replaced with a large flashlight-type dry cell rated at 12 to 16 volts and if the wires are still intact and the contacts clean, the doorbell should come back to life.
Here a 2-way push-button switch is wired to a lamp with 2 bulbs. This diagram can be used to rewire an old push-button lamp with a new switch replacement. The hot wire from the cord is connected directly to the black wire on the switch and the neutral is spliced to the neutral contact on each bulb sockets. The red and blue wires from the switch are each connected to the hot contact on one of the bulb sockets.
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.