---
kind: "section"
citation: "46 C.F.R. § 111.51-5"
title: "46"
number: "111.51-5"
heading: "Protection of vital equipment."
url: "https://uscodex.org/cfr/46/111.51-5"
---

# §111.51-5. Protection of vital equipment.

- (a) The coordination of overcurrent protective devices must be demonstrated for all potential plant configurations.
- (b) Protective relays and overcurrent protective devices must be installed so that:
  - (1) A short-circuit on a circuit that is not vital to the propulsion, control, or safety of the vessel does not trip equipment that is vital; and
  - (2) A short-circuit on a circuit that is vital to the propulsion, control, or safety of the vessel is cleared only by the protective device that is closest to the point of the short-circuit.

## Notes

### Source

Source: USCG-2020-0075, 88 FR 16362, Mar. 16, 2023, unless otherwise noted.

### Authority

Authority: 46 U.S.C. 3306, 3703; DHS Delegation No. 00170.1, Revision No. 01.2. Section 111.05-20 and Subpart 111.106 also issued under sec. 617, Pub. L. 111-281, 124 Stat. 2905.

### Source

Source: CGD 74-125A, 47 FR 15236, Apr. 8, 1982, unless otherwise noted.