Article by Capt. Steve Katz
Rainbow of wires
Our last few articles covered the omnipresent green wire visible in many of the boat’s electrical circuits. But what about all those other colors of wire and the wire itself? Why so many colors and do I need to worry about this when working on my boat?
The American Boat and Yacht Council (ABYC) developed standards that are used by most boatbuilders and incorporated into many government regulations. The ABYC electrical standards are very comprehensive and go into detail about all things electrical on a boat. What we most commonly see are the many colors of wires used on-board. ABYC standards indicate that “each electrical conductor that is part of the boat's electrical system shall have a means to identify its function in the system”. The simplest and easiest way for most boat builders to do this is to use different color wires for different circuits. The ABYC has a predefined color code system that meets the standards and is very often used by boat builders. While most wire is the same color for its entire length, the standard does not require this. The color coding may be accomplished by “colored sleeving or color application to wiring at termination points” and if tape is used to mark a wire, “the tape shall be at least 3/16 inch in width and shall have a sufficient length to make at least two complete turns around the conductor to be marked and the tape shall be applied to be visible near each terminal”.
What’s the difference between the black and yellow DC negative conductors? Black color wire has been in use for many years on all types of DC power systems, not just boats, although boats present a special situation since there is often a mix of DC and AC power systems near each other. Black color wiring is also used on AC power systems as the line voltage conductor, often referred to as the “hot” wire.
As you can understand with both the DC negative and the AC “hot” wire using the same black color, it wouldn’t take much to make a mistake and accidentally touch the wrong wire or make an improper connection that will cause an electrical problem or physical harm. Because of this, the ABYC standards allow the use of yellow wire for the DC negative and some of the wire manufactures call the combination of red and yellow DC wiring “safety wiring”. If you are adding or upgrading the DC electrical system on your boat, using yellow wiring for the DC negative is a good practice.
Another popular way to identify the wiring that meets ABYC requirements, without using predefined colors, is to label the wire as to its function, at a minimum, on each end of the circuit. This can be simply accomplished with a wiring label maker. Some manufacturers, like Viking, print the circuit number and description along the entire length of the wire itself, making circuit identification an easy task. The standards also allow other means of wire identification, providing a wiring diagram of the system indicating the method of identification that is provided with each boat.
A boats electrical wire is also required to be labeled with information about the wire itself, at a minimum, type/style, voltage capacity, wire size, and dry temperature rating. The wire is also often marked with specific industry standards that it is designed to meet.
One popular mis-conception about marine wiring is that it is required to be tinned, that is where each individual copper strand is coated with a thin layer of tin (silver in color) to increase the corrosion resistance. While tinned wire is NOT required, it is often found on quality brands of marine wire and helps to reduce corrosion as compared to bare copper wire.
While the 70+ pages of the ABYC E-11 electrical standard may not be on everyones summer reading list, here are a few good tips from the standards that are useful while working your boat’s electrical systems:
•Wires should be supported every 18-inches along their path.
•No more than four terminals shall be secured to any one terminal stud.
•When installing more than one ring terminal onto a stud, the largest, highest ampacity terminal should be installed first, with successively smaller and lower ampacity terminals installed afterward
•All wire must be at least 16 awg with some minor exceptions.
Your boats wiring is an important part of keeping it in seaworthy condition. Regular inspection and repairs as needed should be made to all electrical systems, making sure you are following ABYC standards.
Captain Steve Katz is the owner of Steve’s Marine Service and holds NMEA, AMEI and NMEA2000 certificates along with ABYC Master Technician certification and factory training from many manufacturers. To reach Steve, call 410-231-3191.
