The maximum allowable voltage drop to remote heads in an emergency lighting system is 10%. This is the amount of power lost between the source and the light, which is regulated by national codes and standards. To ensure that systems remain reliable, a higher standard than normal should be maintained for emergency lighting systems. Additionally, all sources of power loss such as long runs of cable or extra fixtures should be minimized wherever possible. By doing this you can reduce the potential for greater voltage losses and guarantee that your emergency lighting system will work as needed when it's most important.