CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER J—ELECTRICAL ENGINEERING (parts 110 to 113) > PART 112—EMERGENCY LIGHTING AND POWER SYSTEMS > SUBPART 112.20—Emergency Systems Having a Temporary and a Final Emergency Power Source (§112.20-1 to §112.20-15) > 112.20-5—Failure of power from the normal source or final emergency power source.

112.20-5—Failure of power from the normal source or final emergency power source.

(a) If there is a reduction of potential of the normal source by 15 to 40 percent, the loads under § 112.15-1 must be automatically supplied from the temporary emergency power source.
(b) For systems in which a reduction of frequency of the normal source or final emergency power source adversely affects the emergency system and emergency loads, there must be means to transfer the loads under § 112.15-1 to the temporary emergency power source upon a reduction in the frequency of the normal source or final emergency power source.