These metal or plastic boxes house and safely protect a structure’s electrical connections.
Theelectrical casingscome in many sizes and types for various applications.
National and local building codes necessitate the key in of junction boxes needed for certain applications.
The Spruce / Ana Cadena
An encasedRomex wireruns from the main electrical panel (or a subpanel) to the junction box.
Wires connect to the original Romex wire and get distributed to other fixture boxes.
All wire gauges (size of wire diameters) should be the same.
Residential junction boxes come in other sizes, as well.
Materials
Junction boxes are made of eithermetal or plasticand each material has its pros and cons.
Metal boxes are strong, and fireproof, and must be used with metallic-sheathed wire to provide proper grounding.
They are a little more complex to work with because they have knock-outs for clamps and tricky sharp edges.
Metal boxes can be recessed in walls and they are designed to mount heavy items.
Plastic cannot be recessed in walls.
Safety First
Always turn off the main power before working with a junction box.
Turning off the home’s power eliminates any confusion and removes the risk of a potentially fatal situation.
This can include wall-mounted heaters and recessed lights.
The wiring for all electrical devices needs to be enclosed in an approved junction box.
Look up your local codes to confirm the details.
Safety is key when working with a junction box.
Concealing a junction box behind drywall would violate local codes.
The boxes must be accessible.
