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Solid-State Fan Speed Controls
UL 1917
1 Scope
1.1 These requirements cover solid state speed controls rated 300 volts or less, single phase, intended to be connected to 15 - 20 ampere branch circuits and intended to be installed in accordance with the National Electrical Code, ANSI/NFPA 70 and used with:

• Fans and blowers that circulate air, such as desk, bracket, ceiling, hassock, pedestal, and utility fans;
• Fans and blowers that ventilate air, such as attic, wall-insert, ceiling-insert, household hood- and canopy-types, and window fans;
• Evaporative coolers;
• Air-filtering appliances;
• Fan-type deodorizers; and
• Fan-type air fresheners.

1.2 Inductive-type and capacitive-type fan speed controls are also covered by these requirements.

1.3 These requirements also cover the solid state fan speed control portion of controls which include dimmers for use with lighting fixtures.

1.4 Solid state fan speed controls provided with a power supply cord, those intended for permanent connection, and direct plug-in devices are also covered by this Standard.

1.5 These requirements do not cover solid state speed controls used with air heaters incorporating fans, heating-ventilating units, or blowers comprising components of such equipment as furnaces, mechanical-refrigeration equipment, air conditioners, or direct current output applications.

1.6 These requirements do not cover solid state speed controls used with fans intended to be:

• Used in hazardous locations as defined in the National Electrical Code, ANSI/NFPA 70;
• Installed over solvents or chemically flammable liquids or vapors; or
• Located in chemically corrosive environments.