Contents
Where are junction boxes used?
A small metal or plastic junction box may form part of an electrical conduit or thermoplastic-sheathed cable (TPS) wiring system in a building. If designed for surface mounting, it is used mostly in ceilings, under floors or concealed behind an access panel—particularly in domestic or commercial buildings.
Do Ground wires need to be in a junction box?
So while you may not have to connect the equipment grounding conductor to the box, the boxes do have to be grounded and bonded. Since you’re using EMT, the boxes can be grounded and bonded via the conduit. If you were using nonmetallic conduit, you’d have to ground the boxes some how.
When can junction boxes be used?
In short they are used for joining wires or running a spur from an electrical circuit safely. Whenever you need to join two or more electrical wires, then you should use a junction box. As a result they are commonly used and very useful for anyone involved in wiring and electrics.
How many wires can go in a junction box?
For example, the smallest 2 x 4 x 1 1/2-inch deep box can comfortably splice only two cables (four or five conducting wires), while the largest 4 x 4 x 2 1/8-inch-deep boxes can handle as many as four to six cables (up to 18 individual conducting wires).
Why do you need a junction box for wiring?
Junction boxes make wire access easy, since all one must do is remove the covering to make alterations, repairs, or additions to a conduit. Junction boxes also protect wiring from the elements or environment, which can sometimes be corrosive or otherwise harmful to wiring material.
What kind of material is a junction box made of?
Junction boxes are usually between 2 ½ to 3 ½ inches long and made of metal or hard plastic. The functional difference between plastic and metal depends whether or not the junction box is supposed to support any weight.
Why is the Flex not enclosed in the junction box?
• It can be seen that the sheath of the flex is not enclosed. This is due to the junction box connection method not facilitating an easy means of enclosing the outer sheath, a non-compliance with regulation 526.8.