Common Energy Saving Control Methods for Public Facilities

A enclosed public room is sometimes occupied and sometimes vacant. They are unlike large open public spaces and instead require the use of sensors and switches for the purpose of local control. Below are some of the more common methods applicable to such spaces, and which also the specialty of DAE. Set up simply requires a tablet computer with the appropriate interface converter.

  1. Manual on, sensor auto off – for places such as reception rooms, reading rooms, small offices, study rooms, labs, etc.
    1. Wall switches are installed that can be used by the occupant to turn the lights on or off as needed.
    2. If the occupant leaves but forgets to turn off the lights, the sensor will automatically turn the lights off after 10 minutes (adjustable) of not detecting the presence of the occupant.
  2. Manual on, delay auto off – for hallways, stairwells and other passageways.
    1. Multiple push button wall switches are installed along the length of the passage, the user can turn the lights on or off from any of these switches.
    2. If the lights are not turned off manually after 5 minutes (adjustable) the lights will automatically be turned off by the smart switch.
  3. Multiple access – large storage rooms, warehouses, and large data centers
    1. Multiple push button wall switches are installed in convenient areas that allows the user to turn the lights on and off.
  4. Centralized control during peak hours, local switch control during off-peak hours
    1. Peak hours – the lights are forcibly controlled from the control center and the local wall switches are disabled.
    2. Off-peak hours – The control center relinquishes control to the local wall switches, allowing the user to turn the lights on and off as needed.
  5. Centralized control during peak hours, local sensor control during off-peak hours
    1. Peak hours – Depending on whether the local area is daylit or not, the control center will then either forcibly turn the lights on or off, and the local sensors are disabled.
    2. Off-peak hours – The control center relinquishes control to the local sensors; people come, lights turn on; people leave, lights turn off.

Lighting and Air Conditioning For Factories

There many different areas in a factory, different areas have different functions and thus the method of control for each are also different.

  1. Large office areas
    Many employees who work at the factory office are often not at their desks and instead roaming the factory; thus, the office lighting should be divided into department sections, this way, each section can be controlled separately and only as needed. There should be a single switch to turn off all the lights so that the last person to leave the office can simply press one switch to turn off all the lights.
  2. Small offices or work rooms
    Press once to turn on, press again to turn off; for both the lights and air conditioning.
  3. Small meeting rooms
    Press once to turn on, press again to turn off; for the lights with the option to control the air conditioning as well.
  4. Warehouse, equipment rooms
    These have large areas, and should divided into sections for control, each area would be controlled by a sensor with delayed auto off. If the lights are required to remain on for prolonged periods, then there should be a switch in the vicinity to control the lights in that section, a long press would then force the lights the remain on and disregard the sensor. Another press would restore the auto off mode. Or digital switches can also be installed in several places which would then allow for access from multiple locations.
  5. Corridors
    Different methods can be used depending on the space. For hallways adjacent to windows or with natural lighting, lux sensors can be used to turn on the lights when daylight is not enough and automatically turn the lights off. Or multiple switches (with auto off capability) can be placed strategically along the length of the hallway that allow multiple access and also can be integrated into the control center.
  6. Outdoor lighting
    There should be scheduled control with different preset times for each month that change with the seasons. They can also be integrated into the control center.
  7. Centralized control over all lighting and air conditioning, and area scheduled control
  8. Large conference rooms
    Digital switches should be used with pre-assigned patterns for instant recall depending on the event. Digital switches would also control the air conditioning.
  9. Workshop and machinery rooms
    Digital switches would be installed in the workshop, these switches carry signal only and not the actual power to the machines, the switches are linked to the control panels though a digital bus cable. These switches allow the operator to operate the machines from the workshop instead of having to go back and forth to the machinery room.
  10. Workshop lighting
    The lighting would be placed into circuit groups according to their task, the lights would be divided into sections with sectional control, and would also be centrally controlled. There is no need for an all-on and all-off switch.
  11. Air conditioning blower fans
    There would be local switches for control with central control as well.
  12. Emergency power control
    When the power is out, to maximize the utility of the generators, there would be a priority in what equipment to power. Once normal utility power is restored, each load would be switched over in the right sequence.
  13. Emergency help button
    When something unexpected occurs, the emergency button can be pressed which would then flash and sound the alarm simultaneously in different places and also display the location of the emergency to allow for immediate action.

Difference between D-Bus and DALI

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.