Installing Wall Switches

There are various types of wall switches for electrical power.

For example: dimmer switches, combination switch/ receptacles, programmable switches, toggle-type easy to use universal designs for persons of all ages and physical ability. And motion or sound activated switches for on-demand power without lifting a finger.

The three types most often found in homes are single-pole, three-way, and four-way standard design switches. Each can be identified by the number of screw terminals it has; a single pole has two, a three-way has three, and a four-way has four. Newer switches may also have push fittings in addition to screw terminals.

Before installing any type wall switch, turn off the power at your service panel, or the fuse or breaker box. If you are absolutely positive as to which fuse or breaker controls belong to the circuit you will be working on, remove that fuse or trip that breaker. Otherwise, remove the main fuse or trip the main breaker.

Aside from the switch kits, tools required will include:

• Screwdriver
• Knife or stripping wire
• Insulating tape
• Hand cleaner
• Side-cutting pliers
• Cable connectors

Below are directions for installing each of these three types of switches.

Single-pole

The most common type of switch of all, a single-pole switch usually has ON and OFF marks on the switch lever. It is used to break or feed electrical current to a set of lights, or an appliance or receptacle from one location. In addition to two brass terminal screws, most single-pole switches also have a grounding screw.

Important installation points:

• A hot circuit wire will be attached to each screw terminal when correctly wired.
• If two cables enter the box, both hot wires attached to the switch will be black; the switch will lie in the middle of the circuit. Neutral wires and grounding wires should be capped.
• If one cable enters the box, one hot wire will be black; the other will usually be white. A white hot wire will not be plain; it will be coded with black tape or paint. This type insulation is sometimes referred to a “switch loop;” the switch will lie at the end of the circuit.
• When connecting a wire to the terminal screw, always turn the loop on the end of the wire in the same direction as the screw threads. Otherwise, tightening the screw will loosen the loop.

Notes: white wires are generally attached to light-colored terminal screws, such as silver. Black wires are generally attached to dark colored screws, such as brass. If terminal screws are the same color, either wire can generally be attached to either terminal. Green terminal screws are used for grounding wires.

Three-way Switches

These type switches do not have On / OFF markings. They are always installed in pairs; used to control a set of lights from two different locations.

Important installation points:

• One screw terminal will be darker than the others (a dark copper or brown); this is the “common” screw terminal; location will vary according to the manufacturer.
• Two screw terminals will be lighter in color (usually brass); these are called “traveler” terminals and are interchangeable.
• If installation is for a three-way switch in the middle of a circuit, the box should have two cables; one will be a 2-wire cable, the other a 3-wire cable. Connect the black (hot) wire from the 2-wire cable to the darker screw terminal; connect the red and black wires from the 3-wire cable to the two lighter screw terminals.
• When the installation is for a three-way switch at the end of a circuit, connect the wires from the 3-wire cable; the white wire will be hot and should be coded with black tape or ink.

Four-way Switches

These type switches have no On / OFF markings; they are always installed between a pair of three-way switches. This makes it possible to control the flow of electricity to a source from three or more locations. Four-way switches are commonly found in homes with large rooms and multiple living areas; for instance, where a kitchen opens into a dining room.

Important installation point:

• The box should typically contain two 3-wire cables. With most switches, hot wires from one cable should be attached to the bottom or top pair of screw terminals. Hot wires from the second cable should be attached to the remaining pair of screw terminals.

Not all switches are designed the same way, and some box configurations may also vary. For instance, some four-way stitches may have screw terminals that are marked “Line l” and “Line 2.” A pair of color-matched circuit wires will be connected to screw terminals for one line; another pair of color-matched circuit wires will be attached to the other.

Regardless what type wall switch you install, study the wiring diagram and directions that come with the switch carefully. Follow manufacturer’s guidelines to the “T.” Some switches even have a wiring guide stamped right on the back of the device.

Note: working with electricity is tricky business and can represent a danger if not handled properly. Always use extreme caution when working with electricity. Your wisest choice may be to hire an experienced electrician for all electrical aspects of your remodeling and renovation projects.

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