Certification Practice Exam Questions

ABYC Marine Electrical Technician Certification Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

Subjects: DC Systems, AC Systems, Batteries, Bonding And Grounding,

Wiring, Circuit Protection, Safety, Instruments, And ABYC Standards.

• What is the nominal voltage of a fully charged 12-volt lead-acid battery

at rest?

• 11.8 volts
• 12.6 volts
• 13.2 volts
• 12.0 volts

Rationale: A fully charged 12V lead-acid battery measures around 12.6V

open-circuit. Lower readings indicate partial discharge. 1 / 4

• Which wire color is typically used for DC negative in a marine system per

ABYC E-11?

• Green
• Yellow or black
• Red
• White

Rationale: ABYC E-11 allows yellow or black for DC negative conductors to

avoid confusion with AC hot wires.

3. The primary function of a galvanic isolator is to:

• Reduce shore power current
• Increase grounding resistance
• Prevent galvanic corrosion through AC grounding path
• Disconnect batteries automatically

Rationale: A galvanic isolator blocks DC galvanic currents on the AC

grounding conductor while allowing fault current to pass.

• What is the minimum rating for overcurrent protection on a 12 AWG

wire rated for 30A continuous load?

A. 15A

B. 20A 2 / 4

C. 30A

D. 40A

Rationale: The overcurrent device must not exceed the wire’s ampacity; 12

AWG marine wire is rated for 30A.

• What does ABYC require for battery terminal protection?
• No requirement
• Plastic caps optional
• Protection against accidental shorting
• Only positive terminals covered

Rationale: Battery terminals must be protected to prevent accidental

contact or short-circuit.

6. The American Wire Gauge (AWG) system defines wire size based on:

• Diameter
• Cross-sectional area
• Weight
• Resistance only

Rationale: AWG correlates inversely with conductor cross-sectional area;

smaller gauge numbers mean larger wires.

• / 4

7. The primary purpose of a bonding system is to:

• Reduce voltage drop
• Equalize electrical potential between metal parts
• Improve radio reception
• Increase hull conductivity

Rationale: Bonding connects metallic components to maintain equal

potential, preventing stray current corrosion.

8. According to ABYC, AC and DC wiring systems should:

• Be run together in same conduit
• Be physically separated
• Use same color code
• Share overcurrent devices

Rationale: ABYC requires separation of AC and DC conductors to avoid

induced currents and confusion.

• When testing a shore power circuit, which fault would a reverse polarity

indicator detect?

• Open neutral
• Hot and neutral reversed
• Neutral and ground bonded
• Low voltage
• / 4