Simplified ON/OFF
Daylighting Control –
Maximize Energy
Savings
L S - 1 0 1 DAY L I G H T I N G C O N T R O L L E R ®
Easy to Specify, High-Performance
Daylighting Controller
For decades, Watt Stopper/Legrand has focused on
That is why we’ve developed the LS-101, a low-cost,
innovative product development and putting a stop
single zone device that automatically turns lights
to energy waste through energy-efficient lighting
ON/OFF when sufficient natural daylight is present,
controls. We understand the desire to use natural
delivering precise, reliable, repeatable control while
daylight to illuminate a space and minimize energy
meeting the needs of the designer and installer.
consumption, but know that the specification,
installation and commissioning of a daylighting
control system can often be a cumbersome
process.
The LS-101 Daylighting Controller:
• Controls a single zone with a sophisticated digital multi-band photosensor that measures light similar to
the way the human eye perceives it
• Eliminates energy waste during peak demand hours
• Utilizes an easy-to-read Liquid Crystal Display (LCD) to facilitate documentable, repeatable control for
faster commissioning
• Simplifies and speeds up installation with its factory presets
• Meets the requirement for daylighting in California Title 24, Section 119, one of the toughest energy
codes in the country
• Provides the most features at the lowest cost
compared to other products available
• Can be used as an input signal to Watt Stopper’s
Lighting Integrator Lighting Control Panel to
control relays
• Blends into any ceiling with its sleek,
low-profile styling
• Requires only a power pack to operate
Benefits of Daylighting with the LS-101
Daylighting controls transform a daylit area into an
energy-saving opportunity. The U.S.
Environmental Protection Agency estimates
that the potential energy savings from
utilizing such devices can exceed 40%.
Furthermore, since peak electrical
load patterns tend to parallel
periods of the most plentiful
daylight, controlling the electric
lights in response to the presence
of daylight can painlessly reduce
peak load. An optimal daylighting
control system saves energy while
being virtually unnoticeable to the
building occupants. Lights switch off when
daylight levels increase so that the light level
change is not noticeable.
Automatic daylighting controls:
• Maximize the abundant, renewable energy
resource of natural daylight
• Decrease energy consumption
• Increase energy savings
• Expand building sustainability
• Reduce building maintenance due to lengthened
lamp life
• Minimize energy usage during peak demand
periods
2
3
Designed with Features that Make
Energy Code Compliance Easy
Architecturally Attractive Daylighting Control
The sleek, low-profile, round design of the LS-101 blends into any ceiling
or wall and offers the aesthetics for which the architectural community
has been looking. Building tenants will be oblivious to the power hidden
under the flush cover.
Commissioning Made Easy
The easy-to-read LCD prompts you through set-up, if required, and
accurately reflects the current control mode and light levels. The digital
settings for ON/OFF setpoints and time delay settings are easy to read,
document and repeat for faster commissioning, installation and operation.
High-Performance Engineering
The styling of the LS-101 works in tandem with the engineering to deliver
precise control with no more misalignments. Our sophisticated digital
multi-band photosensor measures light similar to the way the human eye
perceives it, with a range of 1-1400 footcandles (fc). This photosensor is
positioned behind a 100˚ cone that cuts off unwanted light, preventing false
triggering. The LS-101 also provides easy setpoint and time delay
adjustments.
Exclusive ‘Hold On While Occupied’ Feature
Add an occupancy sensor to utilize this feature, which prevents turning off
the controlled light as long as the space remains occupied. This allows
energy savings from daylighting control while limiting the impact on
occupants who may find it annoying to have the lights switched off when they
are in the space.
Expandable Switch Override
Include a simple low voltage push-button wall switch to enable the LS101’s lighting control performance to be overridden for one hour, providing
building occupants more control.
The LS-101 automatic daylighting controller has
The LS-101 can also be used to meet energy code
been designed to meet the Mandatory
daylighting requirements in Oregon and Seattle,
Requirements for Lighting Control Devices under
WA, as well as providing daylighting control for
Section 119 of California’s Title 24. And in an
those throughout the country who are looking to
effort to make compliance easy,
exceed their current energy codes that do not yet
Watt Stopper/Legrand’s LS-101 provides
require daylighting controls.
photocontrols that automatically adjust
illuminance levels, and have the capability to
program deadband and time delay.
100
Retaining Nut
Plastic Washer
Daylight
90
Ceiling
Electric Light
80
70
Footcandle
OFF Setpoint
60
ON Setpoint
50
40
Deadband
30
20
Energy Savings Opportunity
10
0
8am 9am 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm
Time
4
5
Designed for Faster
Installation and Set-up
Menu Button
Prompts an installer
through installation and
testing process.
4
Select Button
Allows an installer to easily set
up and test the device without
having to access the plenum.
User-Adjustable
Parameters
Ease Set-Up
1. ON Setpoint
Ranges from 1-850 fc. When the daylight level drops below the setpoint for 20 seconds, the LS-101 turns on
the electric lights. For maximum energy savings, this setting should be at the lowest acceptable light level
when the space is occupied. The factory preset for the ON setpoint is 7.5 fc.
2. OFF Setpoint
Choose one of four possible OFF setpoints that are automatically calculated based on adding 25%, 50%, 75%
or 100% to the ON setpoint. The factory preset for the ON setpoint is 11.25 with a 50% deadband.
3. OFF Setpoint Time Delay
Can be set at 3, 10, 20 or 30 minutes above the OFF setpoint. When the daylight level exceeds the OFF setpoint
for the pre-determined time delay, the LS-101 turns the electric lights OFF. The factory preset for this
parameter is 10 minutes.
4. HOLD ON WHILE OCCUPIED Override
When an occupancy sensor is included in the installation, you can utilize Watt Stopper/Legrand’s exclusive
‘Hold On While Occupied’ feature to ensure lights will not switch off when someone is in the space.
The LS-101 single zone, ON/OFF daylighting
• Two mounting options offer the greatest
controller is one of the easiest devices to install.
flexibility for optimal performance in either top-
And because one device has an extended range of
lit or side-lit applications.
1-1400 fc and straightforward controls, it is the
• No more mis-alignments due to its shape and
simplest to specify and commission.
design.
Wiring an LS-101 is as easy as wiring a Watt
Stopper occupancy sensor. The low voltage leads
• Low-voltage, color-coded wiring facilitates faster
installation.
are color-coded to match the wire colors on the
power pack. Installers can quickly test their wiring
without having to access the ceiling to disconnect
• Programming can be accomplished in most
daylight conditions.
the device.
• LED status indicator identifies if the LS-101 is in
Set-up of the LS-101 requires minimal user-
Override or Test Mode, or if the device has
defined adjustments due to the factory preset
switched the lights on or off.
parameters. Settings for ON setpoint, OFF setpoint
and time delay are adjustable, should changes be
required. For more complex applications, the easyto-read LCD display and two push-buttons will
quickly guide installers through the set-up
process.
Suspended from Ceiling
Side Wall, Hardcap Ceiling or with Electrical Box
Squeeze
Mounting
Screw Hole
Retaining Nut
Plastic Washer
Ceiling
Pull Away
Mounting
Screw Hole
For normal ceiling mounting,
the LS-101 has a threaded
nipple that quickly mounts
on a ceiling tile.
For more challenging applications, such as a side wall,
hardcap ceiling or where an electrical box is required,
remove the nipple and the LS-101 can be attached with two
#6 x 1” self-tapping, pan-head phillips screws.
6
7
Installation Flexibility
of the LS-101
Placement of the LS-101
For optimal performance, position the LS-101 where the illumination from available daylight is
representative of the daylight throughout the controlled space.
Sidelighting
When the primary source of daylight is a
window, mount the LS-101 on the ceiling within
the daylight zone (can extend 12’ or less from
the window) between the window and the first
row of lights.
LS-101
Light Fixture
100°
Peak
Sensitivity
Typical Daylit Zone, about 12' (3.6m)
Toplighting
When the primary source of daylight is a
skylight, mount the LS-101 on the side wall
facing north of the lighted wall, or ceilingmounted next to the skylight with the
photosensor facing down to the floor.
Skylight
LS-101
1
2
100°
100°
Window
Light Fixture
Daylighting
Controls Matrix
LS-101
ON/OFF switching
X
Dimming Control
Single Zone
LS-301
X
Open Loop
X
Closed Loop
X
Adjustable
Setpoint(s)
Adjustable Time Delay
X
LCD Status Display
X
Manual Control Option
X
X
X
X
X
X
10-80% per channel
20-60fc
3, 10, 20, and 30 minutes
LED Status Indicator
X
X
25, 50, 75, 100%
ON Setpoint 1-850 fc
OFF Setpoint
1.25 - 1275 fc
LCD-203
X
X
Up to Three Zones
Adjustable Deadband
LCO-203
5-60fc for each
channel
5-60fc for each
channel
ON, 5-60 seconds
per channel
programmable dimming,
5-60 sec. per channel,
fade rates
OFF, 3-60 minutes
per channel
optional cutoff delay
from 0-20 minutes
displays photocell
readings
displays photocell
readings
wall switch
wall switch
X
X
BT-203
BT-203
LS-290C
LS-290C
LS-4C
LS-4C
LS-8E and LS-12E
LS-8E and LS-12E
open office space
open office space
on remotes
remote adjusts
target levels
Programming
Menu Driven Programming
X
X
Remote Programming
Use with these products
Power Pack
Photocell
Watt Stopper power pack Watt Stopper power pack
included in controller
included in controller
LSR-301-S
and LSR-301-P
Handheld Remotes
System options
Wall Switch
low voltage wall switch low voltage wall switch
Enclosures
Sample Applications
private office
private/open office
cafeteria
classroom
lobby, atrium
classroom
warehouse
corridor
warehouse, retail
restaurant, retail
gymnasium
library
lobby
hallway
8
9
LS-101 Daylighting Controller
D AY L I G H T I N G
C O N T R O L S
100˚ Cone
Digital Multi-Band
Photosensor
LCD Display
Menu Button
Select Button
LED Status
Indicator
Removable Cover
PROJECT
LOCATION/TYPE
Product
Overview
Description
On, Off & Deadband Settings
The LS-101 Daylighting Controller is a single zone,
ON/OFF device which can be installed in an open
or closed loop application to turns lights off
automatically when sufficient natural daylight is
present. It consists of an advanced digital multiband photosensor that measures light similar to
the way the human eye perceives it, an on-board
microcontroller, and an LCD display. This
photosensor is positioned behind a 100˚ cone that
cuts off unwanted light, preventing false triggering.
The LS-101 features adjustable settings for ON
setpoint, OFF setpoint and time delay, should
adjustment be required. Adjusting the ON setpoint
will automatically calculate your OFF setpoint to a
predetermined deadband setting. The deadband
can be adjusted to a value of 25%, 50%, 75% or
100% above the ON setpoint. When the sensed
light level drops below the ON setpoint for 20
seconds, the output signal will switch on. And
when the sensed light level exceeds the OFF
setpoint for the length of the time delay, the output
signal will switch OFF. The time delay can be
adjusted to 3, 10, 20 or 30 minutes.
Operation
The LS-101 is a self-contained 24 VDC device with
an extended range of 1-1400 fc that only requires a
low voltage power pack to operate. By adjusting
the setpoints, it will turn lighting systems off when
the ambient light levels exceed the OFF setpoint,
and will turn lighting systems back on when
natural light levels have fallen far enough to
warrant it. Because of its factory presets, many
set-up applications require little or no adjustment
of the settings. The LS-101 is expandable with a
low voltage wall switch to enable manual override
or with a occupancy sensor to enable its ‘Hold On
While Occupied’ feature.
Features
• Easy-to-read LCD Display prompts installer
through set-up and accurately reflects the current
control mode and light level.
• Four user-adjustable parameters: ON Setpoint,
OFF Setpoint, OFF Setpoint Time Delay, and ‘Hold
On While Occupied’ Mode (if wired with an
occupancy sensor)
www.wattstopper.com
800.879.8585
Applications
The LS-101 Daylighting Controller can be used to
control any type of lighting: incandescent,
fluorescent, compact fluorescent (CFL) and HID .
The sensors work in peripheral offices, skylit
areas, cafeterias, warehouses and any other indoor
areas with natural light access.
• Meets Section 119’s requirement for daylighting in
California’s Title 24 Lighting Code.
• LED status indicator identifies if the LS-101 is in
Override or Test Mode, or if the device has
switched the lights on or off.
• Two mounting options for either top-lit or side-lit
applications
• Test Mode overrides the programmed Time Delay
to allow installer to check if settings are correct.
• Low voltage leads are color coded to match wire
colors on the power pack.
• Control load status verification allows testing and
confirmation that the wiring is correct by pressing
the select button
• Shape and design developed to prevent misalignments.
• Manual Override for one hour (if wired with a low
voltage, push-button wall switch)
• Can be programmed in most daylight conditions
• Location: Suitable for dry interior locations
• Environment: 32 to 120ºF, less than 90% rh
• Dimensions: 2.4” diameter x 0.7” deep (61mm
x 17mm)
• Five-year warranty
Wiring Diagram
Mounting Installation
Power Pack
White
Neut.
Red
Black
Retaining Nut
Plastic Washer
Red
Red
Blue
Hot
Lighting
Load
Blue
+24VDC in
Red
Common
Black
Occupancy Input
White
Common
Control Out
C O N T R O L S
Control Out
LS-101
Ceiling
Any 24VDC
Occupancy Sensor
+24VDC in
Optional
Yellow
LVS-1
Switch
+24VDC in
Optional
Four other wiring diagrams are available at the CAD Resource Center,
www.wattstopper.com
Side Lighting Application
Top Lighting Application
Skylight
1
Light Fixture
100°
2
Peak
Sensitivity
100°
100°
LS-101
LS-101
Window
Light Fixture
Typical Daylit Zone, about 12' (3.6m)
100
Daylight
90
Electric Light
80
70
OFF Setpoint
Footcandle
Deadband
Level Chart
60
ON Setpoint
50
Deadband
40
30
20
Energy Savings Opportunity
10
0
8am 9am 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm
If the LS-101’s photosensor lighting level drops
below the ON setpoint, the lights will remain
on. If the sensor’s lighting level rises above the
OFF setpoint, the LS-101 will automatically
turn the lights off. If the sensor’s lighting level
remains in the predetermined deadband range
(25%, 50%, 75% or 100%) the lighting will be
passive until the sensor’s level reaches the
high or low setpoints.
Time
Catalog No.
Ordering
Information
Pub. No. 24701
LS-101
D AY L I G H T I N G
Wiring &
Installation
Location
• Digital Multi-Band Photosensor Range: 1-1400
foot candles
• ON Setpoint Range: 1-850 foot candles
• Status Indicator: Multi-function green LED
• Power Requirements: 12/24 VDC; 7 mA typical
• Output Signal: 24VDC; maximum 120 mA
Black
Specifications
Voltage
Current
Photosensor Range
Deadband Adjustment Range
12-24 VDC
7 mA Typical
1-1400 foot candles
25%, 50%, 75% & 100%
above the ON setpoint
www.wattstopper.com
800.879.8585
Watt Stopper/Legrand Resources & Tools
CAD Resource Center
Over 300 CAD drawings from which to choose
Wiring diagrams you can place in your own CAD drawings
Available at www.wattstopper.com
Support & Services
Commission and start-up services
District managers, trained representatives and experts
available to answer all technical questions
Continuing Education
Courses throughout North America qualify for AIA/CES
Health, Safety and Welfare (HSW) credit and NCQLP
Lighting Education Units (LEUs)
In-person and on-line events
Course selection available at www.wattstopper.com
Product Selection Guide
Compilation of product ordering information, cut sheets,
design and application assistance
Corporate Headquarters
2800 De La Cruz Blvd.
Santa Clara, CA 95050
WS-05-20076
Tech Support: 800.879.8585
www.wattstopper.com