Emergency Lighting - What is an EM driver?
Emergency Lighting is a code requirement for every commercial building. We will talk more about what it is and why it is needed, but first, what is a driver? In a LED light fixture, a driver uses line voltage alternating current (AC) input and changes it to direct current (DC) to power the LEDs and prevent damage to the boards. LED light fixtures use printed circuit boards, or boards for short, to conduct power to electronic components and remove heat from LEDs and other components to increase the performance and life expectancy of LED lighting.
Emergency drivers work as a battery backup to the regular driver in a LED fixture, allowing the light fixture to function as an emergency light fixture and a part of the emergency lighting system. There are two types of emergency lighting drivers: integral and remote. Remote emergency lighting drivers are designed to power multiple emergency lighting fixtures and are typically located in a central location, such as a basement or electrical room. Integral emergency lighting drivers are located within the individual light fixture, eliminating the need for a central driver.
When power is lost, emergency (EM) lighting fixtures turn on and provide illumination for occupants to exit safely. Electrical codes dictate the length of time an emergency fixture needs to maintain illumination; typically, this is a minimum of 90 minutes.
Regular drivers and emergency lighting drivers must meet safety standards. UL and ETL are nationally recognized independent laboratories that test products and certify them. Although UL and ETL are independent laboratories, the main difference between the two is that UL creates its standards and ensures products meet them, while ETL does NOT develop its own standards.
Choosing the correct emergency driver for the right application is an important consideration. The EM driver should meet the power needs of the fixture and be compatible with the battery system. The driver should also be rated for the conditions in which it is installed. For example, if an EM fixture is needed in a shower or wet room, the driver should be damp or wet-listed to ensure it can resist moisture and corrosion.
Code requires emergency systems and lighting fixtures to be tested at intervals. A quick 30-second test should occur monthly, and a 90-minute test should be done annually. Testing can be done manually, or self-testing systems are available.
In summary, drivers are needed to power LED light fixtures. Emergency drivers are used as battery backup for the fixture when power is lost; this provides illumination for occupants in the space to exit quickly and safely. EM lighting fixtures and their components must meet strict standards, and the EM system must meet minimum requirements for illumination and duration in an emergency.
For more information, check out our EM Drivers vs Small Inverters Chalk Talk