UL History and Standards

This document delves into the history and evolution of UL 924, a crucial standard for emergency lighting and power equipment. Established following significant safety concerns, UL 924 ensures that systems provide adequate illumination and safe egress during power failures. The National Electrical Code (NEC) mandates compliance with UL 924 for emergency lighting systems, specifying requirements for illumination levels, switchover times, and equipment certification.

UL 924 vs. UL 924A

The core distinction lies in their application. UL 924 applies to equipment providing a minimum of 90 minutes of battery-powered illumination during a power failure. UL 924A, or auxiliary, is a site-specific rating where the UPS might rely on additional backup, such as a generator, allowing for a reduced battery runtime (e.g., 15-30 minutes) as the generator ensures the full 90-minute requirement.

Selecting and Testing Equipment

When selecting emergency lighting equipment, it is vital to ensure it meets stringent safety and performance requirements, including illumination levels, battery backup duration, and operational capabilities across various temperatures. Regular testing, including monthly functional tests and annual 90-minute tests, is essential for maintaining compliance and system reliability. Proper record-keeping of all tests and maintenance is also critical to avoid potential fines, legal penalties, and safety hazards.

Eaton's Role in Emergency Lighting

Eaton offers UL 924 tested and certified emergency lighting UPS systems designed for high capacity and efficiency. These systems help reduce risk and navigate emergencies effectively. For more information on Eaton's emergency lighting UPS systems, visit Eaton.com/UL924UPS.