To limit the probability that electrical circuits for the illumination of exit signs will not operate properly [e.g. due to normal power failure, or will fail or be disconnected due to deficiencies with other non-emergency electrical equipment], which could lead to the exit signs not being illuminated in an emergency situation, which could lead to exit locations not being readily identified, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.