There are four different lighting control technologies in the school:
- The Powerlink system by Square D,
- The Clipsal Lighting system by Square D,
- Motion sensor control and end of day shut off with the building automation system, and
- Stand alone occupancy sensors.
Powerlink circuit breaker panels are used in Panels 1B (panel with plexiglass cover) and 2C. The Powerlink system combines a traditional relay-based lighting control panel and circuit breaker wiring panel into one cabinet. Powerlink solenoid operated circuit breakers combine the protective features of a conventional circuit breaker with the switching function of a contactor and therefore eliminate the need for relays and relay cabinets. The intelligence comes from a microprocessor based controller within the panel which receives signals from the internal time scheduler. Control bus strips provide interconnection between the Powerlink circuit breakers and the power interface module. They conduct 24V DC switching power and control signals from the power interface to switch individual circuit breakers and report circuit breaker status to the control module. Corridor lighting and display lighting branch circuits controlled by Powerlink are on a time of day schedule only and not controlled through motion sensors. Exterior lighting connected to the Powerlink system is controlled via a daylight sensor and time of day schedule.
Clipsal Programmable Lighting Control
The gymnasium, resource area, lobbies and mechanical rooms are controlled through the Clipsal programmable lighting system. The lighting control system is a distributed intelligence type network consisting of microprocessor-based lighting control devices connected by a topology-free network using CAT-5 UTP (data cables) to facilitate communications between network devices. Relays and dimmers are placed conveniently in various locations such as ceiling spaces and mechanical rooms. Keypads, occupancy sensors and light level sensors are placed within the controlled room.
Using the Gymnasium as an example, the six lighting branch circuits are controlled through a two channel dimmer; channel one is connected to one half of gym and channel two to the other half. Network wiring connects light level sensor, occupancy sensors and 6 button keypad. The lights are activated with the motion sensors and dim up/down according to the setting of the light level sensor. The 6 button keypad allows occupants to turn each half gym on, turn the whole gym on and dim to three different preset levels. Occupancy sensors shut the lights during the day when the gymnasium is not in use and the Clipsal system turn the area off at a predetermined time at end of day.
Occupancy Sensors and BAS
Typical classrooms and washrooms are controlled through local occupancy sensors, power packs and light level sensors which are all connected to a controller within the building automation system (BAS). The row of lighting parallel to the outside wall has dimming ballasts which are controlled through a light level sensor. Classrooms are designed for 45 to 50 footcandles. When natural sunlight increases the lighting will gradually decrease as the light level sensor measures natural lighting levels. During occupied times, the occupancy sensor and light level sensor controls the room lighting. Manual switching for each row of fluorescents is provided at each classroom entrance in the event the occupants wish all lights to be off. The system turns on/off through the building automation system at end and beginning of day.
Stand Alone Occupancy Sensors
Miscellaneous rooms are controlled through stand alone occupancy sensors and powerpacks or motion sensor switches. The lights are solely controlled through occupant detection and not tied into any central control systems.
Download the Lighting Control System Detail.