Additionally all junction boxes in attic should be under a face plate. Concealing a junction box entirely within the wall is prohibited.
Accessibility for Hazardous Locations: NEC 370-29
You must clearly mark your junction boxes with the appropriate hazardous location classification and any other necessary information, like the maximum temperature rating. You can't conceal junction boxes in ceilings, walls or non-accessible attics and under-floor areas.
NEC 370-29: Junction Box for Hazardous Locations
Junction boxes must be built using materials that are approved for certain environments such as hazardous locations. It must be sealed or designed to prevent the release of vapors or flammable gases. Additionally, grounding junction boxes are necessary.
The box itself is certainly permitted to be behind drywall but the box cover must be exposed to permit access to the wiring in the box.
These have criss-cross yellow lines painted on the road. You MUST NOT enter the box until your exit road or lane is clear. However, you may enter the box and wait when you want to turn right, and are only stopped from doing so by oncoming traffic, or by other vehicles waiting to turn right.
Choose a location for your junction box that is easily accessible and complies with local electrical codes. The box should be mounted securely to a stud or joist, with its face flush to the wall surface. For exterior installations, select a location that provides protection from direct exposure to the elements.
In a word, Safety. These enclose electrical wire connections to protect them from the environment and protect people and animals from the electrical connection. A junction box should always surround the spot where wires join together, and it should always be covered.
No. Not allowed. It needs to be able to access.
The front edge of the box must be flush with the finished wall surface, usually 1/2-inch-thick drywall. Some boxes have depth gauges. You can use a scrap of drywall to position the box.
You cannot conceal junction boxes, ever. They must always be left accessible. When doing new construction electrical work, wiring should be planned so that no junction boxes are necessary. When remodeling, tricks you could use include making splices in receptacle, switch, and lighting boxes.
A junction box is not always necessary if the electrical wires are tucked away. That means the wires are in a conduit and behind the drywall or not exposed.
Junction boxes form an integral part of a circuit protection system where circuit integrity has to be provided, as for emergency lighting or emergency power lines, or the wiring between a nuclear reactor and a control room.
As standard junction boxes have no cable clamps this means the box must be screwed down and the cables fixed to prevent strain on the connections. Care must be taken with the connectors particularly with stranded cables to ensure all the strands are clamped in the connector.
As electrical codes require, every wire connection and cable splice must be housed in an approved plastic or metal box. It is not permitted to bury a box within a wall. A junction box, such as drywall or paneling, cannot be hidden beneath a finished surface.
Wherever you have an electrical connection, that connection needs to be enclosed and protected. Anywhere you have wires spliced together, you need a junction box. Building codes require this protection because contact between wires can cause a spark. That's dangerous.
Junction Boxes with Missing Covers
If easily combustible materials, such as paper or cardboard, are stored near unprotected energized wiring, a spark or electrical arc could easily start a fire. Figures 1 and 2 are examples of junction boxes with exposed wiring.
Plastic electrical boxes can be placed behind drywall. Use only with nonmetallic cable.
Though PVC can melt when overheated, it does not conduct electricity like metal does. Use plastic boxes when: There are non-metallic (NM) cables leading in or out of the box. Metal-sheathed wiring relies on bonding with the metal electric box for grounding and should not be used in plastic boxes.
By code, you must leave access to any splice anywhere. (The only exception is an irreversible crimp on a service entrance cable — a special case requiring an expensive crimping tool.) Splices in attics and crawlspaces are considered accessible as long as there is a hatchway into the space.
When you install an electrical box, make sure it is flush with the surface of this drywall strip; this will ensure the boxes are at the proper depth when the walls are finished.
You can simply use tape over the live wire to fit into the cap. However, it is important to terminate the wire in a junction box and avoid burying the wire in the wall. The tape may come off when temperatures change and in such situations, live electrical wires potentially become dangerous.
Installing the junction box firmly on the wall or ceiling will ensure that it is both accessible and compliant with electrical codes. Enough slack should be left for connections as you run the electrical wires from the main power source to the junction box position.
For example, if you have a light fixture that doesn't need a box for mounting, but the wiring connections are not protected by some kind of cover, then you cannot use the fixture without a junction box. If a fixture meets all of the criteria of a box but lacks a cable clamp, don't use it without a box.