Practice Test Geeks(SAMS) Society of Accredited Marine Surveyors Certified Practice Test
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Vessel Electrical Systems Flashcards

7 cards from real SAMS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. A vessel has a 30-amp, 120V shore power system. What is the maximum continuous load that should be placed on this system according to NEC/ABYC principles?

    Answer: 24 amps

    The standard continuous load derating factor limits loads to 80% of circuit capacity, making 24 amps the maximum for a 30-amp system.

  2. When a marine surveyor observes that a vessel's alternator output wire lacks an overcurrent device near the alternator, the primary risk is:

    Answer: Fire from a short circuit in the unprotected alternator output lead

    An unprotected alternator output lead can carry full alternator current to a fault point with no way to interrupt it, creating a significant fire risk.

  3. Sacrificial zinc anodes on a vessel are part of the:

    Answer: Cathodic protection system

    Zinc anodes are sacrificial metals used in cathodic protection systems to prevent galvanic corrosion of more noble underwater metals.

  4. A surveyor finds that a vessel's bilge blower does not run before engine start. Per USCG regulations, gasoline-powered vessels with enclosed engine spaces must run the blower for a minimum of:

    Answer: 4 minutes

    USCG regulations require a minimum of 4 minutes of blower operation before starting to purge accumulated fuel vapors from enclosed engine spaces.

  5. During inspection of a vessel's electrical panel, a surveyor notes that circuit breakers are used in both the ungrounded (positive) and grounded (negative) conductors. For DC systems, ABYC E-11 requires overcurrent protection in:

    Answer: Only the ungrounded (positive) conductor

    ABYC E-11 requires overcurrent protection only in the ungrounded (positive) conductor of DC circuits; protecting the grounded conductor is not required and can create unsafe conditions.

  6. A vessel's electrical diagram shows a 'common ground buss' connecting all DC negative returns. The best practice for this installation is that the common ground buss should:

    Answer: Connect to the battery negative terminal through a single large conductor, not to the bonding system

    The DC negative buss should connect to the battery negative via a single, appropriately sized conductor and should remain isolated from the bonding system to prevent stray current corrosion.

  7. When surveying a vessel equipped with a diesel engine, the surveyor notes the fuel system lacks a bonding connection to the vessel's bonding system. For diesel vessels, bonding of fuel tanks:

    Answer: Is not required by ABYC because diesel fuel's flash point eliminates ignition risk from static

    Diesel fuel has a high flash point and does not generate ignitable vapors under normal conditions, so bonding for static discharge prevention is not required by ABYC for diesel systems.