---
kind: "section"
citation: "46 C.F.R. § 111.51-2"
title: "46"
number: "111.51-2"
heading: "Short-circuit calculations."
url: "https://uscodex.org/cfr/46/111.51-2"
---

# §111.51-2. Short-circuit calculations.

- (a) The available short-circuit current must be computed—
  - (1) From the aggregate contribution of all generators that can simultaneously operate in parallel;
  - (2) From the largest probable motor load; and
  - (3) **With a three-phase fault on the load terminals of the protective device.**
- (b) The calculated currents must be used to select suitably rated equipment and to allow the selection and setting of protective devices.

## 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.