General-use dimmer switches shall be used only to control what unless listed for other loads and installed accordingly?

• A. Permanently installed incandescent luminaires
• B. Fluorescent fixtures
• C. Motors
• D. Receptacles

Answer: (A)

General-use dimmer switches are designed to vary the brightness of incandescent luminaires because incandescent bulbs present a simple resistive load that responds predictably to reduced voltage. They allow smooth dimming of that type of lighting as intended, when installed correctly and within the device’s ratings.

Using a standard dimmer with other loads isn’t appropriate unless the device is specifically listed for those loads and installed according to the listing. Fluorescent fixtures rely on ballasts that require compatible dimming methods, and a regular dimmer can cause flicker, poor performance, or ballast damage. Motors are inductive and need motor controllers or soft starters designed for speed control, not a lighting dimmer. Receptacles are outlets, not lighting loads, and dimming them isn’t a proper or safe way to control plugged-in devices.

So, the typical and safest use is to control permanently installed incandescent luminaires, unless the dimmer is explicitly listed for other loads and installed accordingly.