46 CFR § 112.20-5 - Failure of power from the normal source or final emergency power source.

---
identifier: "/us/cfr/t46/s112.20-5"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 112.20-5 - Failure of power from the normal source or final emergency power source."
title_number: 46
title_name: "Shipping"
section_number: "112.20-5"
section_name: "Failure of power from the normal source or final emergency power source."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "J"
subchapter_name: "ELECTRICAL ENGINEERING"
part_number: "112"
part_name: "EMERGENCY LIGHTING AND POWER SYSTEMS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "46 U.S.C. 3306, 3703; DHS Delegation No. 00170.1, Revision No. 01.2."
regulatory_source: "CGD 74-125A, 47 FR 15267, Apr. 8, 1982, unless otherwise noted."
cfr_part: "112"
---


# 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.