Technical information

C-BUS
TM
LIGHTING CONTROL
+
DESIGN GUIDE
Planning & Design
The most important phase of any Schneider Electric C-Bus
TM
lighting control project is the planning and design phase. A complete plan starts with a
good understanding of the lighting control requirements. To determine what is required, start by asking the right questions.
1. Where is lighting control required?
For example, a school may have both exterior and interior lighting that requires control. Dene the exterior and interior lighting that requires control, and
segregate lighting by space.
2. How is each space used?
Private ofces within a building may share the same lighting control needs. Meeting and training rooms may have the same lighting control needs,
regardless of where these spaces fall within in a building. Functionally, a classroom differs from a restroom, so the entire site, including interior and
exterior spaces, should be segregated based on the way the space is used. Similarly used spaces may share basic lighting control needs.
3. How will occupants want to control lighting to best utilize the space?
Consider the needs of the occupant. For example, multi-scene control may be used in classrooms, conference rooms and training rooms. Restrooms,
employee break rooms, copier/mail rooms and utility closets may only require occupancy-based control. Exterior parking lot and pathway lighting that is
only needed at night may turn on and off based on time of day or sunrise and sunset. Private ofces may require multi-scene of dimming controls, while
open ofce areas may turn on and off with time of day schedule. While lighting control should save money, it should also enhance the functionality of
the space.
4. What type of lighting is to be controlled?
If dimming is required, the type of lighting must be considered when selecting a dimmer.
5. When is lighting used?
This is important. During working hours, lighting may be used differently than during cleaning hours, for example. Consider the lighting use on week-
ends and after hours. Lighting may not be used during holidays, so it is important to dene when lighting control will be needed giving consideration to
holidays, inventory, shutdown and other events that may occur only once per year.
6. Is occupancy predictable?
If an area has predictable days and hours of occupancy, it may be best to use a time of day schedule to control lighting in this area. For areas with less
predictable occupancy patterns, occupancy-based control may be required, or a combination of control schemes may best meet the functional needs
of occupants and the energy efciency needs of building owner. Having a clear understanding of the occupancy patterns of the building will help the
designer develop a lighting control system that is convenient for occupants and achieves energy efciency.
7. What are the energy code requirements?
Depending on the energy codes governing a particular building, based on its use, its location, and size, there may be specic requirements for lighting
control. Understanding the functional requirements as dened by the governing energy code is essential in the planning and design phase. Oversights
at this point could result in costly changes later to bring lighting and lighting control systems into compliance with building codes. In most energy codes,
lighting and lighting control requirements are intermingled, with some codes providing prescriptive lighting control requirements to bring otherwise non-
complying lighting systems into compliance.
8. What are the functional lighting control requirements for each space?
At this point in the planning process, start dening the functional lighting control needs for each space. This will aid the designer in the product selection
process. Keep in mind that spaces that are used in similar ways may have similar or identical lighting control needs. Grouping spaces based on use
may simplify this process. Lighting functions to consider are:
• Dimming or switching
• Manual or automatic
• Schedule-based shutoff or occupancy-based shutoff
• Mutli-scene or manual dimming control
• Manual or automatic daylighting control
• Zones or groups
9. Finally, what control functions are needed that include more than one space, zone, area or lighting group?
Will the occupant want a single switch to turn on and off all lighting in the building? Will the cleaning crew require special lighting controls to turn on
multiple groups or zones? What type of automatic shutoff shall be used to turn off lighting in the building when the building is unoccupied?
The planning phase usually involves mapping the system requirements, and determining the hardware needs of the system. Thought should be given
to placement and packaging of hardware, programming and cabling requirements. As planning transitions into designing, documentation of the system
layout and functionality becomes more critical.
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