---
kind: "section"
citation: "46 C.F.R. § 129.340"
title: "46"
number: "129.340"
heading: "Cable and wiring."
url: "https://uscodex.org/cfr/46/129.340"
---

# §129.340. Cable and wiring.

- (a) If individual wires, rather than cables, are used in systems operating at a potential of greater than 50 volts, the wire and associated conduit must be run in a protected enclosure. The protected enclosure must have drain holes to prevent the buildup of condensation.
- (b) **Each cable and wire must—**
  - (1) Have stranded copper conductors with sufficient current-carrying capacity for the circuit in which it is used;
  - (2) Be installed so as to avoid or reduce interference with radio reception and compass indication;
  - (3) Be protected from the weather;
  - (4) Be supported so as to avoid chafing or other damage;
  - (5) Be installed without sharp bends;
  - (6) Be protected by metal coverings or other suitable means, if in areas subject to mechanical abuse;
  - (7) Be suitable for low temperature and high humidity, if installed in refrigerated compartments;
  - (8) Be located outside a tank, unless it supplies power to equipment in the tank; and
  - (9) Have sheathing or wire insulation compatible with the fluid in a tank, when installed to comply with [paragraph (b)(8)](#b-8) of this section.
- (c) Cable and wire in power and lighting circuits must be #14 AWG or larger. Cable and wire in control and indicator circuits must be #22 AWG or larger, or be ribbon cable or similar, smaller, conductor-size cable recommended by the equipment manufacturer for use in circuits for low-power instrumentation, monitoring, or control.
- (d) **Cable and wire for power and lighting circuits must—**
  - (1) Comply with [Section 310-13](/cfr/46/310-13.md) of the NEC (NFPA 70), except that no asbestos-insulated cable or dry-location cable may be used;
  - (2) **Be listed by Underwriters Laboratories, Inc.** as UL Boat or UL Marine Shipboard cable; or
  - (3) Comply with [§ 111.60-1](/cfr/46/111.60-1.md) of this chapter for cable, and [§ 111.60-11](/cfr/46/111.60-11.md) of this chapter for wire.
- (e) Cable and wire serving vital systems listed in [§ 128.130(a)](/cfr/46/128.130.md?p=a) of this subchapter or serving emergency loads must be routed as far as practicable from areas at high risk for fire, such as galleys, laundries, and machinery spaces.
- (f) Cable or wire serving duplicated equipment must be separated so that a casualty that affects one cable does not affect the other.
- (g) Each connection to a conductor or a terminal part of a conductor must be made within an enclosure and—
  - (1) Have a pressure-type connector on each conductor;
  - (2) Have a solder lug on each conductor;
  - (3) Have a splice made with a pressure-type connector to a flexible lead or conductor; or
  - (4) **Be splice-soldered, brazed, or welded to a flexible lead or conductor.**
- (h) A connector or lug of the set-screw type must not be used with a stranded conductor smaller than No. 14 AWG, unless there is a nonrotating follower that travels with the set screw and makes pressure contact with the conductor.
- (i) Each pressure-type wire connector and lug must comply with UL 486A. No wire nuts may be used.
- (j) Each terminal block must have terminal screws 6-32 or larger.
- (k) Each wire connector used in conjunction with screw-type terminal blocks must be of the captive type such as the ring or the flanged-spade type.
- (l) No cable may be spliced in—
  - (1) A hazardous location; or
  - (2) **Another location, except—**
    - (i) A cable installed in a subassembly may be spliced to a cable installed in another subassembly;
    - (ii) For a vessel receiving alterations, a cable may be spliced to extend a circuit;
    - (iii) A cable of large diameter or exceptional length may be spliced to facilitate its installation.
    - (iv) A cable may be spliced to replace a damaged section of itself if, before replacement of the damaged section, the insulation resistance of the remainder of the cable is measured, and the condition of the insulation is unimpaired.
- (m) All material in a cable splice must be chemically compatible with other material in the splice and with the materials in the cable.
- (n) Ampacities for conductors must comply with [Section 310-15](/cfr/46/310-15.md) of the NEC (NFPA 70), or with IEEE Standard 45, as appropriate.
- (o) Each conductor must be sized so that the voltage drop at the load terminals does not exceed 10 percent.
- (p) **Each metallic covering of armored cable must—**
  - (1) Be electrically continuous; and
  - (2) **Be grounded at each end of the run to the—**
    - (i) Hull (on a metallic vessel); or
    - (ii) Common ground plate (on a nonmetallic vessel); and
  - (3) **Have final sub-circuits grounded at the supply end only.**
- (q) Each portable or temporary electric cord or cable must be constructed and used in compliance with the requirements of [§ 111.60-13](/cfr/46/111.60-13.md) of this chapter for flexible electric cord or cable.

## Notes

### Authority

Authority: 46 U.S.C. 3306; sec. 617, Pub. L. 111-281, 124 Stat. 2905; Department of Homeland Security Delegation No. 0170.1.

### Source

Source: CGD 82-004 and CGD 86-074, 62 FR 49332, Sept. 19, 1997, unless otherwise noted.