Dexus in full control with state-of-the-art C-Bus Lighting Centralisation

Case Study: C-Bus Lighting Centralisation


Client: Dexus
Location: 360 Collins St, Melbourne VIC
Project Summary: Provide a centralised C-Bus lighting system for all common areas from Level 1 to Level 35 to be controlled and programmed remotely.


360 Collins Street is one of Melbourne’s most prestigious buildings, offering 35 levels of prime office space. Prolux are the electrical maintenance contractors for the A-grade building and have identified the opportunity to greatly improve the lighting control and efficiency within the complex.


Prolux identified the following issues within the building:

  • Each floor above Level 13 was completely independent – no location where all common areas could be controlled from.
  • Each floor above Level 13 identified multiple instances where common area C-Bus supply was fed from tenancy distribution boards and vice versa – problematic when tenant’s left site (turning their power off took out common area C-Bus).
  • No way to monitor energy consumption of common areas – unable to viably source this information or modify programming to provide energy savings.
  • Issues in common areas when works were done in tenancies and vice versa – several floors through the entire building that shared C-Bus cabling for common area and tenancies.
  • Not one database for the entire building – other contractors whom attended site made damaging alterations to programming on different levels, which lead to problematic re-configuring.


The project was to provide a centralised system for all common areas from Level 1 to Level 35 that could be controlled and programmed remotely to facilitate:

  1. Ease of programming for the incumbent.
  2. Full control and monitoring of the system for other programmers – Head End computer linked to the client’s FM office management system.


A distributed intelligent lighting control system was provided to the base building at 360 Collins St. The base building lighting control system was set-up as independent and separate to the tenancy lighting control system, with the ability to be integrated at a later date. The following works were carried out:

  • A local Head End PC already located within the Level 13 electrical riser was utilised to control the entire lighting control system from a central location.
  • C-Bus Controllers were provided for the base building and installed within the lighting distribution boards on each floor.
  • The C-Bus Head End PC and software were configured with control pages for the house lighting and provided time schedules, logic, monitoring and manual override of the house lighting.
  • Lighting control was implemented by programmable DIN rail mounted DALI gateways and relays, with motion sensors controlling the lighting within the area.
  • A special setting was included that allowed for shutting down of the lighting for events such as Earth Hour.

C-Bus Lighting Controls

The lighting control at 360 Collins St falls under three control categories:

  • Automatic – no input required by the end user
  • Semi-automatic – the end user to control, but after an amount of time where no motion has been detected the sensor will automatically switch the lighting off
  • Manual – the end user to control

Automatic C-Bus Lighting Control

Areas falling under automatic control are areas whose main sources of control are only through PIR sensors (passive infrared – an electronic sensor that measures infrared (IR) light radiating from objects in its field of view) and time clock scheduling (turns lights on and off, sets lighting levels for different times of the day and changes the lighting profile for after-hours mode).

Groups that are automatically controlled are likely to be dependent on:

  • the time of day (e.g. business hours)
  • the condition at the time (e.g. sunset)
  • whether there has been presence detected or absence confirmed, or combination of these

Semi-Automatic C-Bus Lighting Control

Areas falling under semi-automatic are areas whose main sources of control are through PIR sensors or a lighting control panel. Areas with this control type are usually within enclosed spaces and have two methods of altering the lighting: through detection of movement via sensor or through a manual user input via the lighting control panel (or combination of both). These areas are not affected by time clock.

Manual C-Bus Lighting Control

Manual control, where the end user makes a deliberate action to control a group. Lighting control panels indicate the state of a group, either ‘on’ or ‘off’ with an illuminated LED. Manual control is also possible for direct control to all areas through the use of a Head End PC.

Functionality – House Areas

These areas operate under an automatic control. Detection of movement via PIR sensors is the main source of input that provides switching of lighting within the space. Behaviour of the sensors depends on the time of the day. During business hours, sensors will operate to turn lights ‘on,’ but will not switch lights ‘off’ until after hours is triggered. During after hours, sensors will operate with a timeout of 30 minutes and set lighting ‘on’ to 100% upon motion. After 30 minutes of no motion detection, lighting will switch to 0%. If at any time motion is detected, lighting will return to 100% and the 30 minute timeout will re-trigger.

Lighting Control Server

The House Lighting Control System has been provided with a C-Bus Head End PC and software located within the Level 13 electrical riser. The C-Bus software will allow for control and monitoring of the house lighting from a central location, as well as the ability to adjust time schedules for the tenancy as needed. General buttons to control each floor is shown in the example template below.

Floor House Lighting Layout

Each floor contains three sections to control and monitor. These buttons will change the state of the whole floor as described:

  1. Status – This shows if the area is in business hours or after hours
  2. Lighting status – This shows the status of the lights in the area. The lights will be able to be controlled also
  3. Manual overrides – Where all lighting will be switched ‘on’ and ‘off’. The sensors can be disabled and enabled from here too
  4. Earth Hour – A schedule has been set up to turn the building ‘off’ for events like Earth Hour

This layout is presented when a level is chosen from the Head End PC on Level 13. From here they will be able to:

  1. Observe the building status – This will inform whether the building in is business hours or after hours
  2. Observe the lighting status of the lights on the floor – There will also be a manual control to turn the lights ‘on’ and ‘off’
  3. Manual overrides for the floor – There will be an override for a master ‘off’, ‘on’ and a button to enable and disable the sensors too


The significant benefits for Dexus have been greater energy efficiency, extra security and a reduction in energy costs.

The ability to fully control any space within the building, achieve the right look and feel as desired is the ultimate in convenience for any client.

Having such enhanced lighting control with C-Bus Automation eliminates any unnecessary running hours. The energy saving measures will also extend the life of light fittings, which will be a significant cost saving over the life of the building.


Prolux supplied and installed:

  • The new back bone communications cable from Level 13 to the new rack on Level 24
  • New cabling was installed from Level 13 to Level 35 to revert back to the Level 24 cabinet from the newly installed area controllers on each level
  • New C-Bus power supplies, cabinets and relays (when required) were also installed to facilitate the full separation of the base building from tenancy’s C-Bus on each level.


To find out how C-Bus Centralisation can improve the efficiency of your commercial building call Prolux Electrical Contractors today on 1800 800 880.