46 CFR § 112.05-3 - Main-emergency bus-tie.

---
identifier: "/us/cfr/t46/s112.05-3"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 112.05-3 - Main-emergency bus-tie."
title_number: 46
title_name: "Shipping"
section_number: "112.05-3"
section_name: "Main-emergency bus-tie."
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"
---


# 112.05-3 Main-emergency bus-tie.

Each bus-tie between a main switchboard and an emergency switchboard must:

(a) Disconnect automatically upon loss of potential at the emergency switchboard;

(b) Be arranged to prevent parallel operation of an emergency power source with any other source of electric power, except for interlock systems for momentary transfer of loads; and

(c) If arranged for feedback operation, open automatically upon overload of the emergency power source before the emergency power source is tripped off the line from the overload.