Category Archives: Lighting Control System

Lighting Control System, Smart Home

Difference between D-Bus and DALI

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The differences between the D-Bus and DALI lighting control systems.

A. The DALI lighting control system

DALI is a lighting control system with a single luminaire as the basic unit of control, in a single distinct zone there can be up to 64 luminaires. An address is assigned to each ballast or LED power of the luminaire, which is matched with a preset digital switch to form a lighting control system. The unique features and limitations of such a system are as follows:

  1. Within the system, there is only a maximum of 64 possible addresses, each luminaire will occupy one address, and thus it is suitable only for small to medium sized venues and is not suited to large scale venues or buildings that has more than 64 luminaires.
  2. When the address needs to be set or when the groups or patterns needs to be configured, a computer installed with special configuration software needs to be used, and the process is very technical and complicated, and it cannot designate what luminaire will use what address.
  3. In a DALI system, each component takes up one of the 64 possible address, and this includes the digital switch as well; thus, the more digital switches there are in a system, the less luminaires can be included.
  4. The power supply used for control in a DALI system is not just any ordinary power supply, it is the system power supply and thus there is a great restriction on the possible wiring distances (which is just enough for a small system with a maximum of just 64 components)
  5. Every system requires a DALI main control unit. If for any reason the main control unit fails, then the entire system dependent on it will also fail. There is absolutely no backup; the safety is dismal.
  6. Every one of the lighting fixture in a DALI system must be DALI branded, and thus any lighting fixture that is not DALI cannot be part of the DALI system. The possible selection of lighting fixtures is thus limited in many ways.
  7. There is no way to make use of different types of sensors, as for example infrared or lux sensors.
  8. If any power supply or ballast fails, replacement is not a simple direct replacement, but rather a DALI specialist or technician needs to redo the address matching process. Both the time and cost to perform the maintenance is detrimental to the proprietor.
  9. DALI is based on each fixture, as such its cost is much greater as compared with systems with circuits as the basic unit of control.
  10. During either the installation or maintenance process, there needs to be matching process and use of the specialized software, so when the electrician finishes with the installation, they are unable to perform any form of testing to verify that the installation is correct, but rather both the electrical and system personnel needs to be on site to perform the verification and commissioning. So not only is the equipment cost high, but the installation and maintenance labor costs are very high as well.

B.  D-Bus Lighting Control System

  1. The basic control unit of the D-Bus lighting control system is a circuit which can consist of any number of lighting fixtures, and not based on a single lighting fixture, thus it can service a lot more lighting.
  2. A single controller can have from 4 to 6 channels with each controlling its own circuit. Up to 64 controllers means that the number of circuits can be from 256 to 512 (note that this is not just the number of individual luminaires); furthermore, D-Bus digital switches does not require having its own address.The D-Bus system can support a whole more luminaires than the DALI system.
  3. The controllers are installed within the flat control panels and is not in the ceilings together with the luminaires; thus, it is much easier to perform diagnostics and maintenance, making the process so much more convenient.
  4. The D-Bus system can be used with any lighting fixture, or LED power supply on the market, and thus there are no limits on the types of luminaire that can be used.
  5. The address on the controllers can be manually set directly from the DIP switches on the front of each unit itself; even groups and patterns can be set manually. Thus installation and maintenance is considerably simplified and convenient.
  6. The D-Bus system can make use of most sensors available on the market or any wall switch plate. Choices are nearly unlimited and replacement is easy.
Energy Management, Energy Saving Switches, Lighting Control System

9 Energy Saving Principles

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  1. Event venues open to the public
    Large public multi-purpose venues such as conference halls and gymnasiums have staff use control switches that are restricted to the public. The staff often needs to roam large areas just to control them which is inconvenient and time wasting. Thus these places are ideal candidates for being remotely monitored and controlled.
  2. Schedule remote control
    The schedule should be easily changed without the need for a specialist. The schedule should have different control methods for peak and off peak periods. During peak periods, local controls are disabled and central control takes over completely. While during off-peak periods, central relinquishes control to the local, and the local control could be achieved using either sensors or wall switches.
  3. Daylight Harvesting
    The purpose of which is to reduce the amount of artificial lighting needed by maximizing the use of natural daylight. This can be achieved by using either a preset time schedule or by using lux sensors during daytime.
  4. Restrict the Use of the A/C
    There should be conditions before the air conditioning can be turned on to avoid having turning them on arbitrarily. These conditions can be in the form of having a temperature limit, time restriction or card insertion before allowing the a/c could be operated.
  5. More Granular Circuit Wiring
    The lights and the air conditioning should be on separate circuits, while each area should divided into smaller areas, this way the lights need not all be turned on and off all at the same time, and only specific areas need to be lit.
    Taking into consideration whether or not the area is exposed to daylight or adjacent to a window is also very important in how the circuit wiring is to be divided.
  6. Single Rooms
    The most power consuming portion of any building are the many individual rooms when added together. Thus they are the focal point of any energy saving measure.
    For rooms that can charge the user for its use, then a prepaid card system or a remote tariff system should be used as much as possible, as these would be the most effective and fair methods to implement energy saving.
    For rooms that are suited to charging the user, then one can make use of a remotely controlled system in conjunction with interactive energy saving smart switches. The purpose of the remote system is to control the room either through a preset time schedule or by the facility manager. The facility manager can decide whether or not to turn on the lights and a/c depending on whether or not there are people present.
  7. Local Conditions
    Rooms with different functions would also make use of different types of energy saving smart switches.
    For discrete rooms or small rooms, one could make use of sensor based energy saving smart switches such as the K24 or the K15. These can be operated in either occupancy or vacancy modes of energy saving control.
    Occupancy mode is used for rooms wherein people go in and out frequently and stay only for a short time such as the restroom or the kitchen.
    Vacancy mode is used for rooms wherein people stay for a long periods of time such as the reception area, lounges and offices.
  8. Air Conditioner Energy Saving Smart Switches (K62)
    In order to avoid having the a/c used unnecessarily, one can utilize the K62. The a/c can only be turned on manually when the temperature conditions are met; when the occupant leaves, the a/c is turned off automatically after a certain delay.
  9. Power Socket Control
    It is not only the lights and the a/c that can be placed under managed control to save energy, but the power sockets can be as well. As a matter of fact, power sockets can be as much a source of saved energy as well and cannot be ignored.