DALI as the driving force behind safety lighting

Safety lighting is the next generation in lighting control. It gives building operators the ability to ensure that occupied areas provide the occupants with safe and adequate lighting at all times.

The basic idealism behind safety lighting could be defined in the following statement:

Emergency lighting + Lighting control + OH&S = Safety lighting

For safety lighting to work adequately it needs to encompass a number of special requirements:

• Individual feedback from all lighting devices including normal and emergency devices. (Feedback needs to include lamp and device status)
• The ability to set minimum lighting levels in all areas
• The ability to set emergency lighting levels in all areas
• Maintenance program
• Flexible control system

The essence of safety lighting

In essence a safety lighting system will provide the minimum lighting required to ensure workers can:

• Evacuate the building during an emergency (covered by the emergency evacuation standards)
• Carry out normal day to day activities without risk.

Many systems today only offer the ability for building occupiers to evacuate the building in an emergency situation where the power may be disconnected. This does not cover situations where the lighting has failed due to lacking maintenance, power surges or other unforeseen circumstances. Below are some examples of safety lighting.

Stairwells

Stairwells are important areas where emergency lighting is used. Under the current emergency standards, emergency lighting is activated when power is lost to the lighting in the stairwell area. A situation exists when power is available, but the lamp/ballast lighting by the stairwell has failed. In this case emergency lights would not be activated in the stairwell, placing occupants at risk.

Safety lighting eliminates this risk by continually monitoring the lighting in the stairwell. If the ballast/lamp that provides the normal lighting fails, the system can initiate a number of safety procedures such as:

• Inform the maintenance personal of failure including lamp or ballast type and location
• Initiate a warning for occupants (could be indication lights or even an email to occupants or managers)
• Turn on emergency lighting to ensure the area is lit
• Turn on emergency lighting only when there are occupants using the stairwell (sensor required)

Office areas

In current times, building designers have been worried about over lighting areas due to energy concerns, however safety lighting takes into account minimum lighting concerns. Employees can suffer from eye-strain or even injury if their office areas are not adequately lit.

Obviously governments have put regulations in place to deal with the minimum lighting levels. However conditions occur where users can be exposed to risk, some of these areas include:

• If the lamp or ballasts in the area have failed
• If the user has control over the lighting level for comfort (dimming control via computer systems or wall switches)

Safety lighting can be used in these areas to ensure that employees are not exposed by:

• Limiting the lighting device’s minimum lighting level
• Compensating the users light by increasing the brightness of surrounding or overlapping lighting.
• Informing the maintenance personal of failure including lamp or ballast type and location
• Initiating a warning for occupants (could be indication lights or even an email to occupants or managers)