Essential Tools

You don’t need to purchase an arsenal of specialized tools to do the electrical projects in this book. For most repairs, a minor outlay will be enough to equip you adequately. Needle-nose and lineman’s pliers are musts. You need the first to bend wires into the loops required for many electrical connections. Lineman’s pliers make it possible to neatly twist wires together. Both also are used to cut wires. Side-cutting pliers make it easy to snip wires in tight places and are ideal for cutting sheathing off cable.

To strip wires use an adjustable wire stripper or a combination tool (which also crimps and cuts wire). If you’re working with nonmetallic cable, use a cable ripper to remove the sheathing easily without nicking the wires. A simple neon tester will tell you if an outlet or fixture is live. A beaded chain simplifies fishing thin, low-voltage wires or phone wires through walls. General carpentry tools that come in handy when doing electrical work include an electric drill with a spade bit to make holes for cable to pass through; a utility knife, screwdrivers, a keyhole saw for cutting drywall, a level, a hacksaw for cutting conduit and metal-sheathed cable, and a tape measure.

Specialized Tools

As you take on more complicated electrical projects, you will find that other tools are invaluable. Some of these tools are essential to such projects; others simply help you do a better, faster job. If you need to drill holes deeper than the length of your spade bit, get a bit extension. A soldering gun with a spool of lead-free, rosin-core solder will be necessary if local codes require soldering.

Always use a fuse puller to remove a cartridge-type fuse; don’t pull it by hand. A BX cutter (this tool can be rented) makes easy and safe work of cutting metal-sheathed cable. A tubing cutter quickly makes clean cuts in conduit. When working with conduit, use a conduit bender to shape the material without crimping it and tongue-and-groove pliers for tightening connectors. For running cable through finished walls and ceilings or wire through conduit, a fish tape makes the job easier.

A continuity tester has a small bulb and battery for testing fuses, switches, and sockets with the power off. A voltmeter works with the power on or off and indicates the amount of voltage at an outlet. A receptacle analyzer runs a number of tests, telling you if your receptacle has a good connection and if it is properly grounded and polarized.

Choosing Switches

Manufacturers offer a sometimes bewildering array of switches. To begin with you have a choice of colors—brown, ivory, and white are the most readily available. But the differences extend far beyond appearance. For most of your needs you’ll probably choose a single-pole toggle, which is available for a low price. “Toggle” simply refers to a switch that flips up and down.

Three-way and four-way switches are needed if you want to control a light from two or more separate switches. If you want to add a switch without putting in a larger box, a double switch may be the solution. It takes up the same amount of space as a single switch. A rocker switch functions the same way as a standard toggle switch but is slightly easier to use. A dimmer switch allows you to adjust lighting levels to suit your needs. A sliding dimmer brightens the light as you slide it upward. The rotary type comes in two versions. One version turns lights on or off with a push; the light level is altered by turning the knob. The other type dims the light as the knob is rotated counterclockwise until it turns off.

Look for the UL Symbol - The UL symbol means that electrical materials have been checked for any defects by Underwriters Laboratories, an independent testing organization. Local codes may prohibit using items not UL-listed.

Selecting Specialty Switches

Of the many available switches built to suit special needs. Take a trip to a home center or a lighting store and you may find the switch that does exactly what you want. If you have power tools or other devices that you don’t want children to play with, consider installing a tamperproof switch. It can be operated only with a key and wired to control the receptacle to which such items are connected.

For security in your backyard, or to have a light automatically greet you as you approach your house, choose a motion-sensor security switch. Its wide-angle infrared beam detects motion and turns a light on automatically. With most units, you can choose how long the light will stay on. A pilot-light switch has a little bulb that glows when power is flowing through the switch. Use it when a fixture or appliance is out of sight. Closet lights, attic exhaust fans, basement lights, and garage lights often are controlled by pilot-light switches.

If you need to squeeze both a switch and an outlet into a single box, use a switch/receptacle. Also use this switch to easily add a receptacle to a room. This switch can be wired so the receptacle is live all the time or wired so the switch controls the receptacle. A programmable switch comes with digital controls and can be programmed to turn lights on and off up to four times a day. This type of switch is useful for security and deterring burglars when you are away from home. A time-delay switch has a dial that can be set to leave a fixture running for up to 60 minutes. Use one for a vent fan, space heater, heat lamp, or garage light.

Choosing Receptacles

A standard duplex receptacle jn\ has two outlets for receiving plugs. Each outlet has a long (neutral) slot, a shorter (hot) slot, and a half-round grounding hole. This ensures that the plug will be polarized and grounded. Receptacles are rated for maximum amps. A 20-amp grounded receptacle has a T-shaped neutral slot; use it only on 20-amp circuits. For most purposes, a 15-amp grounded receptacle is sufficient. When replacing a receptacle in an ungrounded outlet box, use a 15-amp ungrounded receptacle, intended only for use in older homes without ground wires in the circuits. Use a three-pronged plug adapter on an ungrounded receptacle only if the wall-plate screw is grounded. The switch in a combination switch/receptacle can be hooked up to control the receptacle it’s paired with.

A 20-amp single grounded receptacle makes it nearly impossible to overload a critical circuit. For outdoors, in basements, or within 6 feet of a water fixture, install ground-fault circuit-interrupter (GFCI) receptacles. Select a 240-volt receptacle based on the appliance amperage rating. Plugs required for appliances of 15, 20, 30, and 50 amps will have different prong configurations.

Caution! Replace, don't change - Replace a receptacle with one that is just like the old one. Change types only if you are certain that the wiring is suitable. Do not replace an ungrounded outlet with a grounded one unless you know the box is grounded.

Choosing Wire and Cable

Wire, cord, and cable V If (generically referred to as “conductors”) are the pathways along which electricity travels. Wire is a solid strand of metal encased in insulation. Cord is a group of small strands encased in insulation. Cable is made of two or more wires wrapped in protective sheathing of metal or plastic.

Most local codes allow you to use nonmetallic sheathed cable (NM cable) inside walls, floors, and other places where it can’t be damaged and won’t get wet. Information printed on the sheathing tells you what is inside. The top example at right has two 14-gauge wires plus a bare ground wire, and is thus referred to as “14-2 G” cable (“G” for ground). Cable marked “14-3 G” has three wires plus a ground wire. Flexible armored cable (BX) contains wires wrapped in a flexible metal sheathing. It can be used for short runs in exposed areas such as attics or basements. BX needs no separate ground wire because the metal sheathing itself conducts the ground. Underground feed (UF) cable is watertight with the sheathing molded around the wire. Many municipalities permit this for underground lines.

Different gauge wires carry different amounts of electricity— 14-gauge carries a maximum of 15 amps, 12-gauge carries up to 20 amps, and 10-gauge wire up to 30 amps. Doorbells and other low-voltage circuits typically use 18-gauge wire. Unsheathed wires are pulled through flexible or rigid conduit. Flexible metal conduit, or Greenfield, looks like armored cable but doesn’t contain wires. It is cut to length, wires are pulled through it, and the completed pieces installed. With conduit, you pull wires through it after it’s installed.

What the Colors Mean




neutral, carrying power back to the service panel


hot, carrying power from the service panel

red and

also hot, color-coded to help identify which circuit

other colors

they are on

white with black tape

a white wire that is being used as a hot wire

bare or green

a ground wire

Choosing Boxes

An electrical box has one r\ primary function—to house electrical connections. Those connections might be to a switch, a receptacle, the leads of a light fixture, or other sets of wires. Electrical codes require that all wire connections or cable splices be inside an approved metal or plastic box. You cannot bury a box inside a wall; they all must be accessible. This protects your home from the danger of fire and makes it easier to inspect and upgrade your wiring in the future.

Codes govern how many connections you’re allowed to make within a box, depending on its size. If you must make more connections, you have to use a larger box. There are boxes to suit most any depth of wall or ceiling, boxes to support heavy fixtures such as ceiling fans, and boxes for remodeling work and new construction. If, for instance, you’ll be pulling cables through a finished wall, you can choose from a number of retrofit boxes that can be mounted with a minimum of damage to the wall.

Boxes for switches and receptacles serve as the workhorses in any electrical installation. Some of the metal ones can be “ganged” into double, triple, or larger multiples by removing one side and linking them together. Switch/receptacle boxes made of plastic are accepted by most codes, but they can’t be ganged. If you are using conduit, Greenfield, or BX, you must use metal boxes to ground the system. Utility boxes are surface-mounted in basements and garages to hold switches or receptacles. Boxes for fixtures or junctions may support lighting fixtures or split circuits into separate branches.

Box Capacity - Overcrowd a box and you risk damaging wire connectors, piercing insulation, and cracking a switch or receptacle, any of which could cause a short. That is why codes spell out how many wires you can install in a box. The chart above gives standard requirements. Other items may add to the total number of wires a box can hold. As you count wires, keep in mind these rules:

  • Don’t count fixture leads (the wires that are connected to the fixture).
  • Count a wire that enters and leaves without a splice as one.
  • Count each cable clamp, stud, or hickey inside the box as one wire.
  • Count each receptacle or switch as one.
  • Count grounding wires entering a box as one, but do not count grounding wires that begin and end in the box.
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