Ask PYS - Should I Fuse the Alternator?
October 30, 2020 · 3 min · 15K views · Vancouver
What this video covers
Fusing an alternator circuit at the battery protects the boat from fire caused by a short circuit in the wiring.0:50 While a blown fuse while the engine is running can damage an alternator, the fuse serves as a critical safety barrier against catastrophic electrical failure.1:04 If the alternator positive post breaks and the cable contacts the grounded alternator case, a dead short occurs.1:39 Without a fuse, this short can ignite the wiring and lead to a boat fire.1:48 Jeff Cote of Pacific Yacht Systems recommends sizing the fuse at 1.25 times the maximum amperage output of the alternator.2:10 Because an alternator is not a starter circuit, it requires protection like any other appliance on board.2:41 If a properly sized fuse blows, the event indicates a serious underlying fault that requires immediate investigation, regardless of potential damage to the alternator itself.2:16 Prioritizing vessel safety over the preservation of the alternator remains the standard practice for marine electrical installations.2:23
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