Application Note #489
4
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Explanation of Sensing Switch Features (continued)
Advanced Auto-ON Mode:
Auto-ON modes can be customized to respond to different daylight and occupancy
situations. These options will determine the way in which all circuits set to "Auto-ON / Auto-OFF" will respond, upon initial
occupancy. The three available Advanced Auto-ON modes are: Ambient Light Detect (ALD), Off-While-Occupied Enabled
(OWO), and Off-While-Occupied Disabled.
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Ambient Light Detect (ALD):
The lights of all "Auto-ON" (Occupancy) circuits will turn on when occupancy is detected
and ambient light is too low. If the lights turn on when there is already enough natural light, press the Tap button
corresponding to that circuit within 5 seconds of entering the room to turn those lights off. If the lights do NOT turn on
when there is NOT enough natural light in the room, press the Tap button of your Auto-ON circuit(s) within 5 seconds
of entering the room to turn the lights on. The Sensing Switch will learn from these interactions and will eventually only
turn the lights on when there is not enough natural light in the room, based on your preference.
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Off-While-Occupied (OWO) Enabled:
The lights of all "Auto-ON" (Occupancy) circuits will turn on when occupancy is
detected. If the lights are manually turned off, the sensor will keep those lights off as long as the room is occupied. This
is the default setting of the Advanced Auto-ON Modes.
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Off-While-Occupied (OWO) Disabled:
The lights of all "Auto-ON" (Occupancy) circuits will turn on when occupancy
is detected. If the lights are manually turned off, the sensor will wait for 25 seconds before trying to detect occupancy
again. The 25 second period is designed to allow occupants to exit a room without re-triggering the lights, but still
provide the necessary Auto-ON functionality for high-traffic areas.
What do I want?
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If you want the lights to automatically turn on when someone enters the room, and your application is a high-traffic
area (bathroom, hallway, etc), Off-While-Occupied Disabled is recommended, to keep the sensor as responsive to brief
occupancy as possible.
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If you want the lights to automatically turn on when someone enters the room, but you also would like to be able to
turn the lights off and have them stay off while the room is occupied (i.e. conference room presentations, movies, etc),
then Off-While-Occupied Enabled (OWO), should be kept as your Advanced Auto-ON Mode. It is also likely that your
Timeout for this application should be greater than 5 minutes, to increase the chances of maintaining an occupied
status in situations where movement is minimal.
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If you want the lights to remain off when there is already enough natural light in the room, Ambient Light Detect mode
should be enabled to maximize energy savings. This mode should not be used if the sensor switch has a circuit
controlling a fan load in "Auto-ON" (Occupancy) mode, as the fan will then respond based on natural light, as well.
The user(s) must be prepared to correct the sensor with the Tap button if the lights do not respond as expected, upon
entering the room.
Sensitivity:
The sensitivity of the sensor can be adjusted based on the expected level of activity in the room. The
sensitivity setting is "High-Sensitivity," by default, and will perform best for most applications. Rarely, if the sensor is
placed near external sources such as heating and cooling vents, it may turn the lights on without occupancy. If this
occurs, changing the setting to "Low-Sensitivity" should resolve the problem. The default setting is "High-Sensitivity."
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High-Sensitivity:
This is the most sensitive setting and will detect very slight motions. This is the recommended setting,
as it will work well for nearly all applications.
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Low-Sensitivity:
This is the least sensitive setting and is best used in areas of major or large motions.
What do I want?
The type of activity and amount of foot traffic will help dictate at which setting the sensor should be set. High-Sensitivity is
recommended for spaces where the occupants will often be seated for long periods of time and performing fine motions
such as turning a page. Low-Sensitivity is recommended for spaces that generally only experience large motions such as
foot traffic.
Additionally, if the sensor sees a specific area that is not desired (ex: a hallway outside of the room in which the sensor is
installed), Lutron offers a lens mask kit (Lutron P/N 50013614) that can be ordered through Tech Support (1.800.523.9466).
Alternatively, selectively placing opaque tape (painters tape, electrical tape, masking tape, etc.) over certain parts of the
lens can limit its field of vision to block undesired detection areas.