
Crestron GLS-LCL
Crestron Green Light® Photocell, Closed-Loop
Operations & Installation Guide
Further Inquiries
If you cannot locate specific information or have questions after reviewing this guide, please take advantage of
Crestron's award winning customer service team by calling Crestron at 1-888-CRESTRON [1-888-273-7876]. For
assistance in your region, please refer to the Crestron Web site (www.crestron.com) for a listing of Crestron
worldwide offices.
You can also log onto the online help section of the Crestron Web site (www.crestron.com/onlinehelp) to ask
questions about Crestron products. First-time users will need to establish a user account to fully benefit from all
available features.
Future Updates
As Crestron improves functions, adds new features and extends the capabilities of the GLS-LOL units, additional
information may be made available as manual updates. These updates are solely electronic and serve as
intermediary supplements prior to the release of a complete technical documentation revision.
Check the Crestron Web site periodically for manual update availability and its relevance. Updates are identified as
an “Addendum” in the Download column.
WARNING: To avoid fire, shock, or death; turn off power at circuit breaker or fuse and test that power is off before
wiring!
CAUTION: Insufficient power can lead to unpredictable results or damage to the equipment. Please use the
Crestron Power Calculator to help calculate how much power is needed for the system
(www.crestron.com/calculators).
NOTES: Observe the following:
• To be installed and/or used in accordance with appropriate electrical codes and regulations.
• If you are unsure about any part of these instructions, consult a qualified electrician.
Crestron Electronics, Inc. Operations & Installation Guide - DOC. 6773D
15 Volvo Drive Rockleigh, NJ 07647 (2023020)
Tel: 888.CRESTRON 10.11
Fax: 201.767.7576 Specifications subject to
www.crestron.com change without notice.
This product is Listed to applicable
UL Standards and requirements by
Underwriters Laboratories Inc.
FCC Compliance Statement
This device complies with Part 15 of the FCC Rules. Operation is subject to the following conditions:
1. This device may not cause harmful interference, and
2. This device must accept any interference received, including interference that may cause undesired operation.
SETUP
Network Wiring
When wiring the Cresnet® network, consider the following:
• Use Crestron Certified Wire.
• Use Crestron power supplies for Crestron equipment.
• Provide sufficient power to the system.
Preparing and Connecting Wires
Strip the ends of the wires approximately 1/2 inch (13 mm). Use care to avoid nicking the
conductors. Twist together the ends of the wires that share a connection and tin the
twisted connection. Apply solder only to the ends of the twisted wires. Avoid tinning too
far up the wires or the end becomes brittle. The label on the rear of the dimmer contains
a gauge for wire stripping.
Light Level Testing
Before installing the photocell, verify the daylight levels on a sunny day at the proposed
location of the photocell. With the lights switched off, use a light meter to read the daylight
level. Orient the light meter in the same direction the photocell will view. The light levels
under sunny conditions must be at least 35 fc. If the light levels are less, you should select
another location or reorient the photocell
.
DESCRIPTION
The GLS-LCL Closed-Loop Photocell responds to ambient light
levels within an occupied space and provides an analog voltage
proportionate to the ambient light level.
The ambient light measured is the light from any light source in the
visible spectrum. The photocell does not distinguish between
natural sunlight and artificial light. It contains a sensor which is
color and spatially corrected to provide a true representation of
changes in lighting levels that the human eye perceives.
The sensor measures the ambient light that actually falls upon it
within a 60º cone extending downward from the sensor (refer to
“Field of View” illustration below). This is the light that gets reflected
to the ceiling from the walls, floor and furniture.
Field of View
60°
GLS-LCL Specifications
SPECIFICATION
Power Consumption
Output
Recommended Mounting Location Directly above work space
Field of View Coverage
1W (42mA @ 24VDC)
0 - 10VDC (0 - 70 footcandles)
60° Cone
DETAILS
MOUNTING
NOTE: Care must be taken when choosing the mounting location.
It is recommended that the sensor be mounted directly above the
work space, such as a desk, conference table or computer terminal.
Mounting location is important because the ambient light level will
be different at different points in the room, depending on the
location of the windows, lighting fixtures, wall colors, etc. The
ambient light at the doorway can be much less than that at the
windows, corners of the room, or especially on the ceiling. Therefore, it is important to measure the ambient light level over the
workplace.
INSTALLATION
The GLS-LCL can either be fastened onto the ceiling surface, flush
mounted into the ceiling, or installed in a 4" (102 mm) round or
octagonal box, depending on ceiling material and local codes.
1. To fasten the photocell to the ceiling surface, attach the
outer shell provided to the ceiling at the desired location
using two #4 screws and appropriate anchor hardware,
where necessary. For concealed wiring, access to the
space above the ceiling is required, as well as a hole in the
ceiling above the photocell to connect the wires from the
optional GLS-SIM or other Crestron interface device.

Make all connections as described in steps 3 through 7.
Carefully feed the wires into the hole and press the Photocell
body into the outer shell until the rim is flush with the shell.
NOTE: If wiring is to be run exposed along the ceiling, carefully
trim the plastic from the indentation in the side of the outer shell
and lay the photocell wires through it before tightening the shell
onto the ceiling.
2. To flush mount into the ceiling (only allows concealed wiring,
the outer shell is not used), cut a 2" (51 mm) diameter hole
through the ceiling. Make all connections as described in
steps 3 through 7. Carefully feed the wires back through the
hole and press the GLS-LCL into the hole until the rim is
flush with the ceiling.
3. Prepare the photocell lead wires by removing 3/4" (19 mm)
of insulation from each lead to expose bare copper wire.
Make sure the ends of wires are straight.
4. Determine the length of low voltage wires needed to connect
power to photocell. Use wires suitable for low-voltage wiring
according to local electrical codes.
5. Route low-voltage wires from GLS-LCL location(s) to
interface device location(s). (Refer to the wiring diagrams in
the next column.)
6. Prepare low-voltage wires by removing 3/4" (19 mm) of
insulation from each lead to expose bare copper wire. Make
sure the ends of the wires are straight.
7. Connect low voltage wires as shown in wiring diagrams in
the next column (black to ground, red to power, and orange
to the interface device). Twist strands of each separate wire
connection tightly, and push firmly into appropriate wire
connector. Screw connector on clockwise ensuring no bare
conductor shows below the wire connectors. Secure each
connector with electrical tape.
8. Mount the GLS-LCL to the ceiling. INSTALLATION IS
COMPLETE.
TYPICAL APPLICATION DIAGRAMS
Integrating the GLS-LCL into a Cresnet System Via the GLS-SIM
Crestron
2-Series Control
Processor
Cresnet
®
GLS-SIM
GLS-LCL
Integrating the GLS-LCL into a Cresnet System Via the DIN-IO8
or Equivalent*
Crestron
2-Series Control
Processor
Cresnet
®
DIN-IO8
GLS-LCL
*Refer to Wiring Diagrams for details on equivalent devices.
WIRING DIAGRAMS
Connecting S ensors to the GLS-SIM
All wires from sensor to GLS-SIM must
be 24 AWG minimum. (If GLS-SIM is
not located adjacent to the sensor, use
CRESNET-P or CRESNET-NP wire.)
ON
1234
To Control
System
Black
Orange
Red
ON
1234
GLS-S IM
––– NET–––
24 Y Z G
–SENSOR–
24 1 2 G
Use CRESNET-P or
CRESNET-NP wire only
DIP Switch Settings
ON
1
If using
2
input 1
OFF
3
ON
If using
OFF
4
input 2
SPECIAL PROGRAMMING
To ensure correct processing of the sensor’s output from all interface
devices (other than the GLS-SIM), the SIMPL program for the control
processor must disable the pull-up resistor built in to the Versiport
input connector. This is accomplished by setting the “pu-disable”
digital input signal to a “1.”
TROUBLESHOOTING
PROBLEM POSSIBLE
Lights do not respond to
change in ambient light
level.
Incorrect wiring
between sensor and
GLS-SIM (or other
compatible interface).
Improper sensor
location.
Improper control
system programming.
GLS-SIM DIP switch
settings not correct.
CAUSE
CORRECTIVE
ACTION
Refer to the wiring
diagrams in the right
column.
Verify that sensor is
located such that it can
detect the desired
workspace light levels.
Check logic in control
processor, or contact
Crestron for assistance.
Refer to the wiring
diagrams in the right
column for appropriate
settings.
G 1 2 3 4
–––
I/O
–––
24 Y Z G
*
©2011 Crestron Electronics, Inc.
Connecting Sensors to the DIN-IO8 or Equivalent
Blue or
Orange
Black
Red
*
The following Crestron devices may be used
to integrate the sensors into a Cresnet
system by following the schematic shown
here:
DIN-IO8 DIN-AP2 PAC2 PRO2
AV2 CP2E MP2E CNXIO16
Any Crestron product with Versiports
Crestron, the Crestron Logo, Crestron Green Light and Cresnet are trademarks or registered trademarks of
Crestron Electronics, Inc. in the United States and other countries. EMerge Alliance and the EMerge Alliance
logo are either trademarks or registered trademarks of EMerge Alliance Corporation in the United States and/or
other countries. UL and the UL logo, are either trademarks or registered trademarks of Underwriters Laboratories,
Inc. in the United States and/or other countries. Other trademarks, registered trademarks and trade names may
be used in this document to refer to either the entities claiming the marks and names or their products. Crestron
White
CRESNET-P or
CRESNET-NP wire
recommended,
250 feet (76 m) max.
Red
Black
G 1 2 3 4
–––
DIN-IO8
–––
NET
24 Y Z G
Use CRESNET-P or
CRESNET-NP wire only
NOTE: The same Crestron p ower supply
MUST be used to power both the sensors
and the interface d evice (e.g., DIN-IO8).
Otherwise, there is a risk of damage to the
interface device.
disclaims any proprietary interest in the marks and names of others
To Control
System