---
kind: "section"
citation: "46 C.F.R. § 111.51-4"
title: "46"
number: "111.51-4"
heading: "Short-circuit calculations for systems 1500 kilowatts or above."
url: "https://uscodex.org/cfr/46/111.51-4"
---

# §111.51-4. Short-circuit calculations for systems 1500 kilowatts or above.


Short-circuit calculations must be submitted for systems with an aggregate generating capacity of 1500 kilowatts or more by utilizing one of the following methods:

- (a) **Exact calculations using actual impedance and reactance values of system components.**
- (b) **Estimated calculations using IEC 61363-1—** 1998 for AC systems and IEC 61660-1:1997 for DC systems (both incorporated by reference; see [§ 110.10-1](/cfr/46/110.10-1.md) of this subchapter).
- (c) The estimated calculations using a commercially established analysis procedure for utility or industrial applications.

## 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.