BoatHowTo · video

What this video covers

Nigel Calder explains how to detect AC and DC ground leaks on a boat in a short Q&A with host Jan Attenstedt. For AC systems connected to shore power, clamping the shore power cord with a sensitive AC clamp meter reveals any leak current finding a path back to the dock through the water — a reading in milliamps or higher indicates a fault.0:39 DC ground leaks are harder to isolate systematically; the diagnostic principle is identifying disparities between the positive and negative sides of a circuit, which signal that fault current is returning to the battery through an unintended path rather than through the boat's wiring.1:17 Calder points to the negative side of the DC system as the critical factor: a continuous, low-resistance path back to battery negative leaves no alternative route for stray current.2:33 Grounded metal objects aboard create those alternative paths, and they become a problem only when the negative wiring has weaknesses.2:20 Correct wiring from the outset is the primary prevention.Watch

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