What’s an electrical J box?

A junction box is an electrical enclosure that houses one or more wiring connections. The box protects the connections, which usually contain vulnerable points such as wire splices, from environmental conditions and accidental contact.

Do J boxes need to be accessible?

Junction box covers must remain accessible; they cannot be covered with drywall or other surface material. A junction box is most often used where an electrical circuit branches off in two or more directions from a location where an outlet or fixture is not practical.

What is a standard J box?

Junction Box



The standard box used for junctions is a 4-inch square box (either metal or strong plastic), which offers plenty of space for making wire connections with multiple wires or cables, but other types of boxes can be also used for this application. Costs vary based on the type of junction box chosen.

What installations are covered by the NEC?

Now the scope of the NEC mentions that the NEC covers the installation and removal of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and optical fiber cables and raceways.

What is code for electrical junction box?

Securing Cables



Article 334.30 states that cables coming out of the junction boxes should be secured within 12 inches of the box in all boxes equipped with cable clamps. These cable clamps are not to be removed. 314.17(C) states that cables must be secured to the receptacle box.

What NEC article discusses requirements for device boxes?

Article 314 contains installation requirements for outlet boxes, pull and junction boxes, conduit bodies, and handhole enclosures. The specific conditions of use will often determine the type of box and installation methods required.

Which of the following is not covered by the NEC?

The NEC does not cover electrical installations in ships, watercraft,o railway rolling stock, aircraft, or automotive vehicles.

Where are boxes required NEC?

A box shall be installed at each outlet and switch point for concealed knob-and-tube wiring. Fittings and connectors shall be used only with the specific wiring methods for which they are designed and listed.

Which of the following installations would not be covered by the scope of the NEC?

Installations supplying shore power to watercraft in marinas are no longer covered by the NEC. Electrical installations supplying shore power to ships in marinas are covered by the NEC.

Where are junction boxes required?

You’ll need a junction box if you can’t make the connections inside an existing electrical box. You should install the box with the opening facing out from the wall so all the wires inside are accessible. Like any electrical box, it should be installed so that the edge of the opening is flush with the wall.

What are the NEC regulations governing pull and junction boxes?

The minimum length for this box is 32 inches. No extra space is required for additional raceways when calculating the minimum length of a box containing straight pulls. Again, the width and depth of the box must be large enough to provide proper installation of the raceway (or cable), including locknuts and bushings.

How do I choose a junction box?

Quote from the video:
Quote from Youtube video: And if we were going above head into the ceiling different choices there different choices there in that case i actually prefer to use metal even with the non-metallic.

What are the types of J box?

Types of Junction Boxes

  • One-gang Plastic Nail Box. The typical junction box is a one-gang plastic nail box used for ROMEX® wiring, otherwise known as nonmetallic-sheathed cable. …
  • One-gang Metal Cut-in Box. …
  • One-gang Handy Box. …
  • Two-gang Plastic Face Nail Box. …
  • Four-square Metal Box.


What are the 4 types of electrical boxes?

Types of Electrical Boxes

  • Handy Box: Mounts on the surface of a wall. …
  • Junction Box: Wires connect only to each other, never to a switch, receptacle or fixture. …
  • New Work Box: Installed as part of a new construction project. …
  • Old Work Box: Also called a “remodeling box.” Installed on drywall after it has been hung.

Can you put a junction box behind drywall?

As far as the US electrical code is concerned, it directly says no – as in it should NEVER be attempted. If you really must bury something behind the drywall, it should be a continuous run of wire. The code requires that any sort of connection, be it repair work or a splice, should be easily accessible.

Does a junction box have to be attached to a stud?

They don’t need to be fastened to a stud, so you can install them anywhere.

Can you splice Romex in wall?

You can’t splice it in the wall or use a j-box that would be buried (code). You will need to back pull it and replace the run to the fixture. Concealed splicing is not permitted. The only correct way to splice is replace the section and/or do the splice in accessible junction boxes.