This rule is demonstrated nicely by wall switches receptacles and standard light fixtures all of.
Wiring ceiling light junction box.
How to wire an electrical junction box.
Lighting circuits using junction boxes.
The round or octagonal box houses lightweight fixtures or safety devices in the ceiling.
These are used for lights or smoke and carbon monoxide alarms.
Metal boxes are suitable for surface mounted installations using metal conduit.
They provide much more room for wiring than shallow round pan boxes and can be used as junction boxes.
Depending on the age of the home there may be one or more cables found in the ceiling junction box.
A junction box is used to add a spur or to extend circuits and direct power to lights and additional sockets.
Be sure to choose a ceiling box that is made to support extra weight.
Electrical codes generally require that all electrical devices and the wiring connections to those devices must be enclosed in an approved electrical box often known as a junction box this metal or plastic box includes a cover to protect the wiring within and protect you from the wiring.
Advice on wiring electrical junction box with easy to follow junction box wiring diagrams including information on 20 and 30 amp junction boxes.
Octagon and standard size round boxes range from 1 1 2 to 3 inches deep and are the standard box for ceiling or wall mounted light fixtures weighing up to 50 pounds.
The junction box effectively replaces the ceiling rose.
An alternative method this uses the same wiring principles as the looped ceiling roses but here the connections are made in junction boxes rather than the ceiling rose.