Special Purpose Electrical Switches

1. Special Purpose Electrical Switches W. C.”Buster Hounshell Spring 2002

2. Double Switches • A double switch has two switch levers in a single housing • It is used to control two light fixtures or appliances from the same switch box.

3. Double Switches • Single-circuit wiring: Three black wires are attached to the switch • The black feed wire bringing power into the box is connected to the side of the switch that has a connecting tab

4. Single-circuit wiring • The wires carrying power out to the light fixtures or appliances are connected to the side of the switch that does not have a connecting tab • The white neutral wires are connected together with a wire connector

5. Double SwitchSeparate-circuit wiring • Four black wires are attached to the switch • Feed wires from the power source are attached to the side of switch that has a connecting tab, and the connecting tab is removed

6. Double SwitchSeparate-circuit wiring • Wires carrying power from the switch to light fixtures or appliances are connected to the side of the switch that does not have a connecting tab • White neutral wires are connected together with a wire connector

7. Removing the connecting tab • Remove the connecting tab on a double switch when wired in a separate-circuit installation • The tab can be removed with needle- nose pliers or a screwdriver

8. Pilot-light Switches • A pilot-light switch has a built-in bulb that glows when power flows through the switch to a light fixture or appliance • Pilot- light switches often are installed for convenience if a light fixture or appliance cannot be seen from the switch location

9. Pilot-light Switches • A pilot-light switch requires a neutral wire connection • A switch box that contains a single two- wire cable • Has only hot wires and cannot be fitted with a pilot- light switch

10. Switch/receptacles • A switch/receptacle combines a grounded receptacle with a single-pole wall switch • In a room that does not have enough wall receptacles, electrical service can be improved by replacing a single-pole switch with a switch/receptacle

11. Timer Switches • Timer switches have an electrically powered control dial that can be set to turn lights on and off automatically once each day • They are commonly used to control outdoor light fixtures

12. Time-delay Switches • A time-delay switch has a spring-driven dial that is wound by hand • The dial can be set to turn off a light fixture after a delay ranging from I to 60 minutes • Time-delay switches often are used for exhaust fans, electric space heaters, vent fans, and heat lamps

13. Automatic Switches • An automatic switch uses a narrow infrared • beam to detect movement • When a hand passes within a few inches of the beam, an electronic signal turns the switch on or off • Some automatic switches have a manual dimming feature

14. Automatic switches can be installed wherever a standard single-pole switch is used Automatic switches are especially convenient for children and persons with disabilities. Automatic switches require no neutral wire connections For this reason, an automatic switch can be installed in a switch box containing either one or two cables The wire leads on the switch are connected to hot circuit wires with wire connectors Automatic Switches

15. Motion-sensor Security Switches • A motion-sensor switch uses a wide-angle infra- red beam to detect movement over a large area • Turns on a light fixture automatically • A time-delay feature turns off lights after movement stops

16. Most motion-sensor switches have an override feature that allows the switch to be operated manually Better switches include adjustable sensitivity control and a Variable time-delay shutoff control. Motion-sensor switches require no neutral wire connections They can be installed in switch boxes containing either one or two cables The wire leads on the switch are connected to hot circuit wires with wire connectors Motion-sensor Security Switches

17. Programmable Switches • Programmable switches represent the latest in switch design • They have digital controls and • Can provide four on-off cycles each day

18. Programmable switches frequently are used to provide security when a homeowner is absent Programmed lighting is a proven crime deter- rent For best protection, programmable switches should be set to a random on-off pattern. Programmable switches require no neutral wire connections They can be installed in switch boxes containing either one or two cables The wire leads on the switch are connected to hot circuit wires with wire connectors Programmable Switches

19. Dimmer Switches • Any standard single-pole switch can be replaced with a dimmer, as long as the switch is of adequate size. Dimmer switches have larger bodies that standard switches. They also generate a small amount of heat that must dissipate. For these reasons, dimmers should not be installed in undersized electrical boxes or in boxes that are crowded with circuit wires. Always follow the manufacturer’s specifications for installation.

20. Dimmer Switches • Dial-type dimmer is the most common style. Rotating the dial changes the light intensity.

21. Dimmer Switches • Slide-action dimmer has an illuminated face that makes the switch easy to locate in the dark.

22. Dimmer Switches • Automatic dimmer has an electronic sensor that adjusts the light fixture to compensate for the changing levels of natural light. An automatic dimmer also can be operated manually.