Romex cable installation

Romex wire is a type of electrical wiring used in residential and commercial construction. Romex wire is made from either copper or aluminum with a PVC coating that makes it resistant to corrosion. The insulation on the wire is rated for damp and wet conditions, but the wire itself should never be exposed to water.

Romex wire is usually used for indoor wiring in residential or commercial construction. Romex wire is not designed for outdoor use. Another type of knockout has no slot and must be punched out with a hammer and screwdriver. Hit it hard and it will bend down away from the hole don't worry; you won't hurt the box. Grab the knockout disc with pliers and twist it until it comes free. Now you're ready to use one of the following types of clamps to secure an NM cable to the box.

Some metal boxes come with saddle-shaped clamps already mounted inside the box. Usually, there are two clamps that can hold two cables each. If a clamp is not next to the knockout you are using, simply unscrew the clamp and move it to the desired location. There should be a pre-drilled hole for the clamp screw near each pair of knockouts. Insert the cable into the knockout and slide it under the clamp.

Tighten the clamp's screw to secure the cable. A locknut-type clamp is the classic metal cable clamp with a short, threaded cylinder and locknut on one end and a saddle-type clamp with two screws on the other end. To install this type of clamp, insert the threaded end into a knockout hole in the box, then thread on the locknut onto the threaded end from inside the box.

Tighten the nut with pliers. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products.

List of Partners vendors. Tip If THHN is being used, the conduit must run from termination point to termination point because THHN cannot be used outside the protection of conduit or another approved enclosure. Featured Video. Read More. Your Privacy Rights. To change or withdraw your consent choices for TheSpruce. At any time, you can update your settings through the "EU Privacy" link at the bottom of any page. These choices will be signaled globally to our partners and will not affect browsing data.

We and our partners process data to: Actively scan device characteristics for identification. Understanding electrical junction boxes and what they are used for. Home electrical wiring is the process of installing electrical wire to a location that will serve electrical devices or an appliance.

One very important component is the box where the wire will be installed. The type and size of the home wiring electrical boxes will depend upon the circuit size, application and its location.

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