Electrical Systems - General

FIGURE 1 - Applicability

NOTE:
Boats powered with outboard engine(s) are not subject to these regulations unless there is also a gasoline powered engine installed on the boat such as a gasoline powered auxiliary generator. The outboard motor and its associated control wiring are excepted. Associated control wiring includes power cables, ignition wires, gauge wires, etc. A battery used only for the trolling motor becomes part of its associated control wiring and is therefore not subject to the regulation’s requirements, including the battery securing and restraint requirements of 183.420.

The gauge of a wire is its size. The American Wire Gauge is a nationally accepted convention for designating wire sizes. The higher the number, the smaller the diameter of the wire. For example, 16 gauge wire has a smaller diameter than 12 gauge wire. For large sizes of wire, 0, 00, 000 and 0000 are used. The more zeros, the larger the wire.

FIGURE 2 - Conductor Gauge (insulation not included)

Conductors may be labeled with their size. If not, and the size is to be determined, then measure the diameter of an individual strand using a micrometer. Square the diameter of the strand (in mils) and multiply by the number of strands in the conductor. This will provide the total circular-mil area of the conductor. Refer to Table 1 to find the gauge.

TABLE 1 - Conductors

Formula:

CM=d2 x N

Where:

d = diameter of one strand in mils (one mil = .001 inch)

N = number of strands in the conductor

NOTE:

1. If the conductor contains strands of various sizes, measure the diameter of each strand, square the diameter, and add the individual circular mil area for the conductor.

2. Below 50 volts, SAE wire size may be used.

3. 50 Volts and above, AWG wire size MUST be used.
    

In general, any item related to the electrical system is an electrical component. A panel box is NOT itself an electrical component, but it contains a number of electrical components. Support clamps and straps and their fastenings are NOT electrical components.

It must be noted that the regulation’s requirements apply to the installation of electrical components, and their external connection into the electrical circuit. The regulation does not apply to internal wiring or terminations within a component. For example, the windings of a motor, generator or alternator are not regulated; however, the external wiring used to connect them to a boat’s electrical system is required to comply with the regulation. The construction details of electrical components are only regulated insofar as whether the electrical component is or is not ignition protected.
 

Pigtails are the wires that are provided by a device manufacturer to connect the device into the electrical circuit. Pigtails are usually electrically connected internally and led through a protective covering to be connected to electrical service connectors. Examples of electrical devices that are commonly equipped with pigtails are cabin lighting fixtures, navigation light fixtures, blowers, bilge pumps, horns, searchlights, indicator lights, in-line fuses, switches and solenoids.

The regulation exempts pigtails that are less than 7 inches in length, only from:

183.425 - Conductors: General
183.430 - Conductors in Circuits of Less Than 50 Volts
183.435 - Conductors in Circuits of 50 Volts or More
183.455 - Overcurrent Protection: General

To determine the length of pigtails, measure the length of conductors that are visible outside the device, i.e. from the point on an electrical component where the conductors pass through a shell or housing to their end. This length must be less than 7 inches if the pigtails are to be excepted from these requirements. The portions of the conductors inside the component are not part of this pigtail length. In bilge installations, the pigtail connections must not be below the level of normal bilge water accumulation.
 

A "sheath" is a flexible continuous covering, as distinguished from a "conduit" or "duct" which are rigid continuous coverings. As the regulation states, a "sheath" may be a continuous wrapping of electrical tape, molded or extruded rubber or plastic, or flexible tubing (sometimes referred to as "spaghetti").

A "sheath" may be used around one or a number of conductors, which may or may not be different gauges. Each of the conductors must be insulated, that is, the sheath is NOT to take the place of a conductor’s insulation.

A "sheath" does not have to hold the conductors tightly bonded together. Individual conductors are allowed to move in relation to each other within a sheath. A "sheath" is generally used as a means of grouping conductors to maintain a neat appearance as the conductors are run through the boat.

The equipment standards of this regulation appear to impose requirements, and consequently certification responsibilities on component manufacturers. This is not the case. The boat manufacturer is the responsible party under these regulations and he must certify compliance.

What does certification mean? Certification means to test and verify that the boat complies with the law.

The boat manufacturer is required to certify that the boat complies with this standard, not the equipment manufacturers of each component. Component parts of outboard engines and portable equipment, such as a self-contained engine-generator unit, are not covered by these regulations.

Purchase orders can stipulate that component manufacturers assure compliance, which a boat manufacturer may choose to recognize as supporting evidence in certifying the entire electrical system. Recognized, acceptable marine listings or labels may be used as supporting evidence of compliance. This does not, however, relieve the boat manufacturer of certification responsibility.