{"id":16382,"date":"2026-10-27T14:10:32","date_gmt":"2026-10-27T13:10:32","guid":{"rendered":"https:\/\/sutars.com\/en\/?page_id=16382"},"modified":"2026-11-02T13:16:10","modified_gmt":"2026-11-02T12:16:10","slug":"which-cables-to-choose","status":"publish","type":"page","link":"https:\/\/sutars.com\/en\/wired-inspired\/cables-connectors\/which-cables-to-choose\/","title":{"rendered":"Which cables to choose"},"content":{"rendered":"\t\t
\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t

Which cables to choose<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
\n\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t
\n\t\t\t
Hem<\/a> \/<\/span> Page<\/span><\/div>\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t

A boat\u2019s electrical system places greater demands on cables and conductors than many land-based installations.<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

Vibration, moisture, salt, oil and temperature fluctuations make conductor construction, insulation, cross-sectional area and color identification important.<\/span><\/p>

This guide explains what to choose and what to avoid when installing 12 V, 24 V and single-phase AC systems on boats, based on the requirements of the applicable standard for recreational craft. This is a European standard.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

\n\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t

Which colors apply to AC (230 V alternating current) and DC (12 V, 24 V direct current, etc.)?\n<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t
Function<\/b><\/td>Permitted\/specified colour<\/b><\/td>Important<\/b><\/td><\/tr>
DC positive (+)<\/b><\/td>Identified by colour or other clear marking<\/span><\/td>Black or yellow must NOT<\/strong> be used.<\/span><\/td><\/tr>
DC negative (\u2212)<\/b><\/td>Black or yellow<\/span><\/td>If black is used as an AC live conductor, DC negative (-) shall be yellow.<\/strong><\/span><\/td><\/tr>
DC equipotential bonding<\/b><\/td>Green or green\/yellow; uninsulated strip or braid is also permitted<\/span><\/td>Shall not<\/strong> be used as a current-carrying conductor.<\/span><\/td><\/tr>
AC line, single-phase<\/b><\/td>Black or brown<\/span><\/td>Yellow, green or green\/yellow shall not<\/strong> be used.<\/span><\/td><\/tr>
AC neutral, single-phase<\/b><\/td>White or light blue<\/span><\/td>Yellow, green or green\/yellow shall not<\/strong> be used.<\/span><\/td><\/tr>
AC protective conductor<\/b><\/td>Green or green\/yellow<\/span><\/td>Reserved for the protective conductor function.<\/span><\/td><\/tr><\/tbody><\/table>

DC positive +<\/span><\/h2>

Identification methods other than insulation colour are permitted for DC positive, provided that the conductors are correctly identified in the boat\u2019s wiring diagram. Black and yellow insulation shall not be used for DC positive.<\/span><\/p>

DC negative \u2212<\/span><\/h2>

DC negative conductors shall be identified by black or yellow insulation. If the boat also has an AC system in which black is used as a live conductor, yellow must be used for DC negative.<\/span><\/p>

In a boat with both AC and DC systems, yellow DC negative provides a clearer distinction when black is used as an AC conductor.<\/span><\/i><\/p>

Avoid AC colors in DC systems<\/span><\/h2>

In boats with both AC and DC systems, brown, white and light blue insulation should be avoided in the DC system unless the conductors are clearly separated from AC conductors and identified as DC.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\"\"\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
\n\t\t\t\t\t
\n\t\t
\n\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\"\"\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t

Sheathing and insulation<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t
Environment\/system<\/b><\/td>Requirements according to the source material<\/b><\/td><\/tr>
DC distribution<\/b><\/td>Conductor insulation must be flame-retardant.<\/span><\/td><\/tr>
Engine compartment<\/b><\/td>Minimum temperature rating of 70 \u00b0C. Insulation must be oil-resistant or protected by insulating conduit or sleeving.<\/span><\/td><\/tr>
AC outside engine compartments<\/b><\/td>Minimum temperature rating of 60 \u00b0C.<\/span><\/td><\/tr>
AC conductors and flexible cords<\/b><\/td>Voltage rating of at least 300 V to 500 V, with stranded copper conductors.<\/span><\/td><\/tr><\/tbody><\/table>

Distinguish between conductor insulation and any common outer sheath. The requirements must be met wherever the respective part is exposed to heat, oil, moisture or mechanical stress.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

\n\t\t\t\t
\n\t\t\t\t\t

Minimum conductor cross-sectional area<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

Arrangement<\/b><\/p><\/td>

Minimum cross-sectional area<\/b><\/p><\/td>

Restriction\/note<\/b><\/p><\/td><\/tr>

Separately installed conductor<\/b><\/p><\/td>

1 mm\u00b2<\/span><\/p><\/td>

Applies when the conductor is longer than 175 mm.<\/span><\/p><\/td><\/tr>

Conductor in a multicore cable with a common sheath<\/b><\/p><\/td>

0.75 mm\u00b2<\/span><\/p><\/td>

May extend no more than 800 mm beyond the outer sheath.<\/span><\/p><\/td><\/tr>

Internal wiring in a distribution panel<\/b><\/p><\/td>

0.75 mm\u00b2<\/span><\/p><\/td>

An exception.<\/span><\/p><\/td><\/tr><\/tbody><\/table>

Please note: The minimum cross-sectional area is not automatically the correct cable size. The final cross-sectional area shall be selected based on the load, current-carrying capacity, and allowable voltage drop.<\/p>

Feel free to use our cable calculator<\/a> <\/strong>to find the correct cable size.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

\n\t\t\t\t\t
\n\t\t
\n\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t

Keep AC and DC separate\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

DC conductors shall not be installed in the same wiring system as AC conductors without an approved method of separation. Examples include:<\/span><\/p>