Vessel Electrical Systems Flashcards
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Read the first 7 Vessel Electrical Systems flashcards as text
According to ABYC E-11, what is the maximum allowable voltage drop for a vessel's DC lighting circuit?
Answer: 3%
ABYC E-11 specifies a maximum 3% voltage drop for lighting circuits on recreational vessels.
A marine surveyor finds bare copper conductors used throughout a vessel's bilge wiring. This is a concern primarily because:
Answer: Bare copper corrodes rapidly in the marine environment and may cause high-resistance connections
Bare copper in the bilge environment oxidizes and corrodes, creating high-resistance connections that can cause overheating and fire.
Which type of battery is most commonly recommended for dual-battery systems on recreational vessels due to its tolerance for deep discharge?
Answer: Deep-cycle battery
Deep-cycle batteries are designed to be repeatedly discharged to a significant portion of their capacity without damage, making them ideal for house banks.
When inspecting shore power connections on a vessel, a surveyor should verify that the shore power cord receptacle is rated for:
Answer: At least 125% of the maximum load current
Shore power receptacles must be rated for at least 125% of maximum load current to prevent overheating under continuous use.
On a vessel with a 12V DC system, a surveyor measures 0.5V drop across a battery switch under load. This indicates:
Answer: Excessive resistance likely due to a corroded or loose switch contact
A 0.5V drop across a battery switch represents significant resistance that indicates corroded or deteriorated contacts requiring replacement.
A vessel's engine compartment contains fuel tanks and an AC inverter. The inverter installation must:
Answer: Be ignition-protected to prevent sparks that could ignite fuel vapors
Any electrical equipment in an enclosed engine compartment with gasoline fuel systems must be ignition-protected per ABYC and USCG requirements.
Which NFPA/ABYC standard governs the installation of electrical systems on recreational boats in the United States?
Answer: ABYC E-11
ABYC E-11 is the primary standard governing DC and AC electrical systems on recreational vessels in the United States.