WattStopper launches first dual loop photosensor for reliable, energy-efficient control of spaces with skylights
SANTA CLARA, CA. May 13, 2013 – WattStopper announced the new LMLS-600 dual loop photosensor
that provides superior automatic daylighting control for applications with skylights. Developed in
cooperation with the California Lighting Technology Center (CLTC), Wal-Mart and three California utilities,
the device includes two photosensors – an open loop sensor to detect daylight contribution, and a closed
loop sensor to read the ambient light level – and sophisticated algorithms to simplify setup and ensure
The LMLS-600 is the first commercial product to combine open and closed loop daylighting control
strategies to prevent unwanted lighting changes, and increase energy savings. During normal operation,
the closed loop sensor provides control based on the ambient light level. However, if the device detects
occupant interference, the open loop sensor takes control for the remainder of the day. Previously,
daylighting control for skylit areas typically relied on open loop solutions, which can cause distracting
changes to electric light levels when the sun is low in the sky. Closed loop solutions overcome this
problem, but on their own tend to over dim or under dim the lights.
The new photosensor features automatic commissioning, including self-calibration and establishment of
setpoints, saving time for installers and improving performance. Additionally, it recalibrates itself every
night to adapt to reflectance changes in the space, such as a new furniture layout, a new retail display or
lamp lumen depreciation.
The LMLS-600 can be set up for switching or dimming control, and is part of WattStopper’s Digital Lighting
Management (DLM) suite of intelligent controls. Combined with DLM room controllers, it can control most lighting
loads, including LEDs. Set up is ladder free, from a wireless handheld configuration tool that is also used to
customize a wide variety of DLM control parameters.
Proof-of-concept demonstrations showed the dual-loop solution achieves 36% energy savings compared to the
24% achieved by the open-loop solution. This 50% increase in performance will help lighting, design and building
professionals comply with new code requirements for daylighting controls and energy efficiency in commercial,
retail, warehouse, and industrial applications.
Editorial Contact and Photos:
Rita Renner, Marketing Communications Manager
WattStopper | 2800 De La Cruz Blvd. Santa Clara, CA 95050
Direct Tel: 408-486-7526, Fax: 408-988-5373
WattStopper (www.wattstopper.com), a Legrand group brand, is a leading manufacturer of energy efficient lighting controls for commercial and residential use. We help customers find convenient ways to save energy, meet green initiatives, and comply with energy codes with our comprehensive range of products, programs, and services. Legrand (www.legrand.com), located in Limoges, France, is the world specialist in products and systems for electrical installations and information networks, offering solutions for use in residential, commercial and industrial buildings.