Exception: Where a manual control provides light reduction in accordance with Section C405.2.2.2, automatic controls shall not be required for the following:
- Sleeping units.
- Spaces where patient care is directly provided.
- Spaces where an automatic shutoff would endanger occupant safety or security.
- Lighting intended for continuous operation.
- Shop and laboratory classrooms.
Each space provided with time-switch controls shall also be provided with a manual control for light reduction in accordance with Section C405.2.2.2. Time-switch controls shall include an override switching device that complies with the following:
- Have a minimum 7-day clock.
- Be capable of being set for seven different day types per week.
- Incorporate an automatic holiday "shutoff" feature, which turns off all controlled lighting loads for at least 24 hours and then resumes normally scheduled operations.
- Have program backup capabilities, which prevent the loss of program and time settings for at least 10 hours, if power is interrupted.
- 5.1. The override switch shall be a manual control.
- 5.2. The override switch, when initiated, shall permit the controlled lighting to remain on for not more than 2 hours.
- 5.3. Any individual override switch shall control the lighting for an area not larger than 5,000 square feet (465 m2).
- 1.1. The time limit shall be permitted to be greater than 2 hours, provided that the override switch is a captive key device.
- 1.2. The area controlled by the override switch is permitted to be greater than 5,000 square feet (465 m2), but shall not be greater than 20,000 square feet (1860 m2).
- 2.1. Spaces that have only one luminaire with a rated power of less than 100 watts.
- 2.2. Spaces that use less than 0.6 watts per square foot (6.5 W/m2).
- 2.3. Corridors, equipment rooms, public lobbies, electrical or mechanical rooms.
Spaces required to have light-reduction controls shall have a manual control that allows the occupant to reduce the connected lighting load in a reasonably uniform illumination pattern by at least 50 percent. Lighting reduction shall be achieved by one of the following or another approved method:
- Controlling all lamps or luminaires.
- Dual switching of alternate rows of luminaires, alternate luminaires or alternate lamps.
- Switching the middle lamp luminaires independently of the outer lamps.
- Switching each luminaire or each lamp.
Exception: Light reduction controls are not required in daylight zones with daylight responsive controls complying with Section C405.2.3.
Manual controls for lights shall comply with the following:
- Shall be readily accessible to occupants.
- Shall be located where the controlled lights are visible, or shall identify the area served by the lights and indicate their status.