Nonmetallic sheathed cable run through notched framing members
The National Electrical Code (NEC) and most local codes permit the homeowner to do anything a licensed electrician can do as long as the homeowner is the only one residing in the residence. A licensed electrician must perform all work on income properties. Like the professional electrician, the homeowner must apply for and get a wiring permit from the city's building department before undertaking any electrical wiring project. Like the professional electrician, the homeowner must have all the required inspections performed by the Authority Having Jurisdiction (AHJ), the local electrical inspector.
The rules and regulations pertaining to installing electrical wiring vary from one wiring system to another. This article will focus on just one of them, wiring with nonmetallic cable because it's the most frequently used in home wiring. Does this Spark an idea?
Instructions
1. Battery powered drill-driver
Lay out your proposed wiring project on graph paper drawn to scale. Take this drawing along with a detailed list of the materials you intend to use to the building department and apply for your wiring permit. Some cities allow you to apply for and pay for the permit online while others requires you to apply in person. Don't start any wiring project until you have received the permit and posted it on the premises as required.
2. Spade bit
Route nonmetallic cable along the sides of framing members (floor joists, wall studs, and rafters) or through holes drilled through framing members. When running cable along the side of framing members, position the cable so that it's at least 1 and ¼ inches from the nearest edge of the framing member. Cables run alongside of framing members must be supported by cable staples at intervals not exceeding 48 inches. When running cable through holes drilled in framing members, drill the holes so that the nearest edge of the holes is at least 1 and ¼ inches from the member's nearest edge. These are all NEC requirements. Cables run perpendicular through holes in the framing members need no additional support because framing members are installed 18 inches on center (O.C.) in the United States.
3. Hammer
Route nonmetallic cable behind baseboards by cutting channels in the wall finish and notching the wall studs. Make the notches ¾ to 1 inch deep. Figure 5/8-inch width for each cable to be laid in them. Lay the cables in the notches and cover them with steel nailing plates. Steel nailing plates are required by code to protect them from being damaged by nails and screws. Running cables behind baseboards is often the easiest way to route new cable while doing as little damage as possible to finished walls.
4. Reciprocating saw
Mark the locations for all device boxes that will house general-purpose duplex receptacles. Locate the boxes so that no point along the unbroken floor line is more than 6 feet from a receptacle -- this is a code requirement. Each duplex receptacle is considered two receptacles and covers a 6-foot span to each side of the box it's mounted in. When these intervals fall between two studs, use the stud that keeps the interval 6 feet or under for the first box and 12 feet or under for the boxes following the first one.
5. Wood chisels
Mount the device boxes for the receptacles so that the top of the boxes is 12 inches from the finished floor line. Position the boxes on the studs so that the lip of the box will be even with the finished wall surface. This is a code requirement. Mount device boxes for light switches in a similar manner except mount them 46 inches above the finished floor line.
6. Razor knife
Insert the cable ends into the boxes so that they extend 6 to 8 inches from the box. This is a code requirement and applies to all types of boxes.
7. Adjustable wire strippers
Remove the outer jacket from the cable ends using the razor knife. Be careful to not nick or cut the insulation on the individual insulated wires. Electrical inspectors will check for this kind of damage and make you redo any cable run where this is found.
8. Needle nose pliers, diagonal cutting pliers, and Lineman's pliers
Remove ¾ inches of insulation from the ends of the insulated wires with the wire strippers. Be careful to not cut into the copper wire itself during the stripping process. This will weaken it and the inspector will make you redo these wires before "Green Tagging" your job.
9. Two-gang device box
Call for the "rough in" inspection.
Tags: framing members, inches from, boxes that, code requirement, device boxes
