---
kind: "section"
citation: "46 C.F.R. § 111.54-1"
title: "46"
number: "111.54-1"
heading: "Circuit breakers."
url: "https://uscodex.org/cfr/46/111.54-1"
---

# §111.54-1. Circuit breakers.

- (a) **Each circuit breaker must—**
  - (1) **Meet the general provision of Article 240 of NFPA 70 or IEC 60092-202—** 2016 (both incorporated by reference; see [§ 110.10-1](/cfr/46/110.10-1.md) of this subchapter) as appropriate;
  - (2) Meet [subpart 111.55](/cfr/46/subpart111.55.md); and
  - (3) Have an interrupting rating sufficient to interrupt the maximum asymmetrical short-circuit current available at the point of application.
- (b) No molded-case circuit breaker may be used in any circuit having a nominal voltage of more than 600 volts (1,000 volts for a circuit containing a circuit breaker manufactured to the standards of the IEC). Each molded-case circuit breaker must meet [section 9](/cfr/46/9.md) and marine supplement SA of ANSI/UL 489 or IEC 60947-2:2019 (both incorporated by reference; see [§ 110.10-1](/cfr/46/110.10-1.md) of this subchapter), except as noted in [paragraph (e)](#e) of this section.
- (c) Each circuit breaker, other than a molded-case one, that is for use in any of the following systems must meet the following requirements:
  - (1) An alternating-current system having a nominal voltage of 600 volts or less (1,000 volts for such a system with circuit breakers manufactured to the standards of the IEC) must meet (all incorporated by reference; see [§ 110.10-1](/cfr/46/110.10-1.md) of this subchapter):
    - (i) IEEE C37.13;
    - (ii) IEEE C37.27; or
    - (iii) **IEC 60947-2—** 2019.
  - (2) A direct-current system of 3,000 volts or less (1,500 volts or less for such a system with circuit breakers manufactured to the standards of the IEC) must meet IEEE C37.14 or IEC 60947-2:2019 (both incorporated by reference; see [§ 110.10-1](/cfr/46/110.10-1.md) of this subchapter).
  - (3) An alternating-current system having a nominal voltage greater than 600 volts (or greater than 1,000 volts for IEC standard circuit breakers) must meet (all incorporated by reference; see [§ 110.10-1](/cfr/46/110.10-1.md) of this subchapter):
    - (i) IEEE C37.04, IEEE C37.010, and IEEE C37.12; or
    - (ii) **IEC 62271-100—** 2017.
- (d) A circuit breaker must not:
  - (1) Be dependent upon mechanical cooling to operate within its rating; or
  - (2) Have a long-time-delay trip element set above the continuous current rating of the trip element or of the circuit breaker frame.
- (e) Each circuit breaker located in an engineroom, boilerroom, or machinery space must be calibrated for a 50 degree C ambient temperature. If the circuit breaker is in an environmentally controlled machinery control room where provisions are made for ensuring an ambient temperature of 40 degree C or less, a circuit breaker must have at least the standard 40 degrees C ambient temperature calibration.

## Notes

### Amendments

[USCG-2020-0075, 88 FR 16363, Mar. 16, 2023]

### 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.

### Amendments

[USCG-2020-0075, 88 FR 16363, Mar. 16, 2023]