SAMS Vessel Electrical Systems 5

Question 1

A vessel's lightning protection system should include a ground plate with a minimum underwater surface area of:

Accepted Answer

1 square foot

Answer

0.25 square feet

Answer

2 square feet

Answer

4 square feet

Question 2

During a survey, the inspector finds that a vessel's AC panel has Ground Fault Circuit Interrupter (GFCI) protection on all AC outlets in the head compartment. This installation is:

Accepted Answer

Correct and required by ABYC A-31 for protection in wet locations

Answer

Unnecessary since vessels are not required to follow NEC requirements

Answer

Deficient because GFCI devices are not approved for marine use

Answer

Over-specified since only 240V circuits require GFCI protection

Question 3

Electric Shock Drowning (ESD) risk near docked vessels is primarily associated with:

Accepted Answer

AC current leaking into the water from a vessel's shore power system creating a voltage gradient

Answer

DC leakage from deteriorated battery cables

Answer

Stray current from corroding bronze through-hulls

Answer

Lightning discharge conducted through bonding wires

Question 4

A surveyor observes that a vessel uses wire nuts to splice conductors in the bilge area. This is deficient because:

Accepted Answer

Wire nuts are not approved for marine use and can loosen or corrode; marine-grade terminals or solder with heat shrink are required

Answer

Wire nuts are rated for only 12V DC systems

Answer

Wire nuts exceed the maximum permitted splice resistance per ABYC

Answer

Wire nuts are only approved for temporary connections under USCG rules

Question 5

A vessel equipped with a diesel generator must have the generator's neutral conductor:

Accepted Answer

Isolated from the vessel's bonding/grounding system to prevent shock hazard

Answer

Connected to the vessel's bonding system for safety

Answer

Bonded to the engine block at the generator

Answer

Connected to shore power neutral when docked

Question 6

When evaluating wire sizing for a DC circuit on a vessel, the surveyor must consider:

Accepted Answer

Both the ampacity for conductor protection and voltage drop for acceptable circuit performance

Answer

Only the ampacity based on insulation temperature rating

Answer

Only the voltage drop to ensure lights are bright enough

Answer

Only the wire gauge specified by the equipment manufacturer

Question 7

A surveyor finds that a vessel's battery cables are routed through the bilge without any chafe protection where they pass through a bulkhead. The primary risk this presents is:

Accepted Answer

Insulation chafe creating a short circuit capable of starting a fire

Answer

Increased resistance due to the longer cable route through the bilge

Answer

Violation of USCG color coding requirements for DC cables

Answer

Excessive voltage drop due to cable contact with bilge water