WAC 296-307-37406. Emergency power systems

This section applies to circuits, systems, and equipment intended to supply power for illumination and special loads, in the event of failure of the normal supply. (1) Emergency circuit wiring must be kept entirely independent of all other wiring and equipment and must not enter the same raceway, cable, box, or cabinet as other wiring. Exception: This does not apply where common circuit elements suitable for the purpose are required, or for transferring power from the normal to the emergency source. (2) Where emergency lighting is necessary, the system must be arranged so that the failure of any individual lighting element, such as a burned out light bulb, cannot leave any space in total darkness.