Pre-Purchase Inspections
September 2010 - Incorrect Wire

Wires are wires, as long as they carry the electricity that’s all that counts, right? Of course that’s wrong and even folks who have no experience in the world of boat building and repair are likely to be suspicious of such a statement. In the inspections I carry out I routinely encounter all manner of wiring types, many of which are woefully inadequate for marine applications.

The standards established by the American Boat and Yacht Council are very clear about the requirements for the type of wiring that should be used for various applications, from shore power to battery connections. However, even in the absence of those standards some faults are exceedingly clear to see.

The wiring shown in this image, connected to the battery bank aboard a vessel undergoing an SDMC Pre-Purchase Inspection, is made up of a few large strands; it’s designed to be used in household and industrial applications for supplying power to circuit breaker distribution boxes and large equipment like lathes or ventilation systems, not marine battery banks.

Because there are so few strands per cable it is all but inflexible, making it poorly suited to a vibration-prone small craft environment and, perhaps more importantly, cable of this sort is not designed to be utilized with crimp-on connectors such as the one shown in this image. When wire of this sort is crimped it makes contact with the connector in just a few locations, which leads to high resistance and the generation of heat. Additionally, the interface between the cable and the connector is exposed, and therefore prone to ingress of moisture, which leads to corrosion.

By contrast, the correct cable for this application is extremely flexible by virtue of the number of fine strands of which it’s made. The cable shown here consist of approximately seven or eight large “strands”, while the proper cable, known in the industry as Type 2 or Type 3, is made up of 125 or over 800 strands respectively for this given gauge. Tinning, the coating or plating of the individual strands to reduce corrosion, while highly desirable, is not necessary for ABYC compliance.

This installation fails to meet ABYC standards as well as common sense protocols, making its reliability questionable at best.

If you're interested in finding out more about Pre-Purchase Inspections like the one described above, system inspections, vessel selection assist, the Captains’ Club (simply click on these words to be taken to the relevant sections of this website) or other services offered by Steve D'Antonio Marine Consulting, email or call 804-776-0219.