ABYC ELECTRICAL EXAM STUDY GUIDE 2026
– COMPLETE CONCEPT REVIEW & PRACTICE
MATERIALS (LATEST EDITION)
1. What is the minimum allowable ampacity for a conductor used in a branch circuit protected
by a 20-amp circuit breaker?
A) 15 amps
B) 20 amps
C) 25 amps
D) 30 amps
Answer: C) 25 amps ✓
2. According to ABYC, which color is reserved exclusively for the safety ground (bonding)
conductor?
A) Green or Green with a Yellow Stripe
B) Yellow
C) White or Gray
D) Red
Answer: A) Green or Green with a Yellow Stripe ✓
3. What is the primary purpose of the vessel's DC grounding (bonding) system?
A) To carry fault current back to the source
B) To provide a low-impedance path to mitigate galvanic corrosion
C) To provide a common return path for DC loads
D) To equalize potential and minimize shock hazard from AC faults ✓
4. A conductor passing through a bulkhead must be protected by:
A) A fuse within 7 inches of the bulkhead.
B) A grommet or equivalent protection. ✓
C) Double insulation.
D) A junction box on both sides.
5. The maximum voltage drop for a navigation light branch circuit from the power source to
the load is:
A) 3%
B) 10% ✓
,C) 5%
D) 7%
6. Which of the following is NOT an acceptable method for supporting a wiring run?
A) Plastic cable ties with UV inhibitor
B) PVC conduit straps
C) Solid copper wire used as a lacing cord ✓
D) Adel clamps or cushioned cable clamps
7. A conductor's ampacity is reduced (derated) when it is in a bundle of more than how many
current-carrying conductors?
A) 2
B) 3 ✓
C) 5
D) 7
8. The correct termination for a stranded conductor under a screw-type terminal requires:
A) Soldering the strands together before installation. ✓
B) A crimped-on ring terminal or similar pressure connector.
C) Twisting the strands tightly and applying dielectric grease.
D) A plain fork terminal.
9. The main source of DC negative return current on a boat is the:
A) Bonding system
B) Engine negative terminal ✓
C) Zinc anode
D) Ground plate
10. A marine-rated circuit breaker is designed to:
A) Trip at 100% of its rated current in a 40°C ambient temperature.
B) Trip at 100% of its rated current in a 25°C ambient temperature.
C) Carry 100% of its rated current indefinitely without tripping in a 40°C ambient temperature.
✓
D) Trip at 80% of its rated current to provide a safety margin.
11. Which battery cable should be disconnected FIRST when servicing a DC system?
A) The negative cable at the battery ✓
B) The positive cable at the battery
C) The negative cable at the engine block
D) The positive cable at the starter solenoid
,12. Ignition protection is required for electrical equipment installed in which of the following
spaces?
A) The cabin
B) A permanently installed fuel tank compartment
C) An engine compartment or any space containing fuel-fired equipment ✓
D) A lazarette containing only bilge pumps
13. What is the primary function of an ACR (Automatic Charging Relay)?
A) To prevent battery overcharging
B) To automatically combine battery banks for charging and isolate them for discharging ✓
C) To convert AC to DC power
D) To act as a main battery disconnect switch
14. The ABYC standard for battery installations requires that a battery be secured against
movement of what angle?
A) 10 degrees in any direction
B) 90 degrees in any direction
C) 45 degrees in any direction
D) 30 degrees in any direction ✓
15. A bilge blower must be rated for what type of service?
A) Ignition protected ✓
B) Waterproof (IP68)
C) Corrosion resistant
D) Explosion proof
16. The maximum allowable voltage drop for a bilge pump branch circuit is:
A) 3%
B) 5%
C) 7%
D) 10% ✓
17. Which of the following is an approved color for a 12V DC positive conductor?
A) White
B) Yellow ✓
C) Green
D) Green/Yellow
18. When sizing a main DC feeder cable from the battery to a distribution panel, the ampacity
must be at least what percentage of the sum of the connected load ampacities?
, A) 100%
B) 115%
C) 125% ✓
D) 150%
19. What is the primary hazard of using an automotive-type battery charger on a marine
battery bank?
A) It charges too slowly.
B) It may not be ignition protected and could cause an explosion. ✓
C) It cannot reach a full state of charge.
D) It uses the wrong voltage.
20. A GFCI (Ground Fault Circuit Interrupter) is required on a boat for which of the following?
A) All 12V DC outlets
B) 120V AC outlets in the head, galley, machinery spaces, and on deck ✓
C) The main AC shore power inlet
D) The battery charger circuit
21. The shore power galvanic isolator or isolation transformer is intended to prevent:
A) AC short circuits
B) DC stray current corrosion from other boats in the marina ✓
C) Overloading the shore pedestal
D) Lightning strikes
22. Which statement about wire size is true?
A) A larger AWG number indicates a larger diameter conductor.
B) Voltage drop is the primary concern for sizing DC conductors. ✓
C) Conductor insulation color determines its minimum ampacity.
D) The length of the circuit has no bearing on conductor size.
23. To minimize voltage drop in a long circuit, you should:
A) Increase the conductor size. ✓
B) Decrease the conductor size.
C) Increase the circuit voltage.
D) Add a capacitor in series.
24. The ABYC standard for AC system color coding states that the equipment grounding
conductor should be:
A) White
B) Green or Green/Yellow ✓
– COMPLETE CONCEPT REVIEW & PRACTICE
MATERIALS (LATEST EDITION)
1. What is the minimum allowable ampacity for a conductor used in a branch circuit protected
by a 20-amp circuit breaker?
A) 15 amps
B) 20 amps
C) 25 amps
D) 30 amps
Answer: C) 25 amps ✓
2. According to ABYC, which color is reserved exclusively for the safety ground (bonding)
conductor?
A) Green or Green with a Yellow Stripe
B) Yellow
C) White or Gray
D) Red
Answer: A) Green or Green with a Yellow Stripe ✓
3. What is the primary purpose of the vessel's DC grounding (bonding) system?
A) To carry fault current back to the source
B) To provide a low-impedance path to mitigate galvanic corrosion
C) To provide a common return path for DC loads
D) To equalize potential and minimize shock hazard from AC faults ✓
4. A conductor passing through a bulkhead must be protected by:
A) A fuse within 7 inches of the bulkhead.
B) A grommet or equivalent protection. ✓
C) Double insulation.
D) A junction box on both sides.
5. The maximum voltage drop for a navigation light branch circuit from the power source to
the load is:
A) 3%
B) 10% ✓
,C) 5%
D) 7%
6. Which of the following is NOT an acceptable method for supporting a wiring run?
A) Plastic cable ties with UV inhibitor
B) PVC conduit straps
C) Solid copper wire used as a lacing cord ✓
D) Adel clamps or cushioned cable clamps
7. A conductor's ampacity is reduced (derated) when it is in a bundle of more than how many
current-carrying conductors?
A) 2
B) 3 ✓
C) 5
D) 7
8. The correct termination for a stranded conductor under a screw-type terminal requires:
A) Soldering the strands together before installation. ✓
B) A crimped-on ring terminal or similar pressure connector.
C) Twisting the strands tightly and applying dielectric grease.
D) A plain fork terminal.
9. The main source of DC negative return current on a boat is the:
A) Bonding system
B) Engine negative terminal ✓
C) Zinc anode
D) Ground plate
10. A marine-rated circuit breaker is designed to:
A) Trip at 100% of its rated current in a 40°C ambient temperature.
B) Trip at 100% of its rated current in a 25°C ambient temperature.
C) Carry 100% of its rated current indefinitely without tripping in a 40°C ambient temperature.
✓
D) Trip at 80% of its rated current to provide a safety margin.
11. Which battery cable should be disconnected FIRST when servicing a DC system?
A) The negative cable at the battery ✓
B) The positive cable at the battery
C) The negative cable at the engine block
D) The positive cable at the starter solenoid
,12. Ignition protection is required for electrical equipment installed in which of the following
spaces?
A) The cabin
B) A permanently installed fuel tank compartment
C) An engine compartment or any space containing fuel-fired equipment ✓
D) A lazarette containing only bilge pumps
13. What is the primary function of an ACR (Automatic Charging Relay)?
A) To prevent battery overcharging
B) To automatically combine battery banks for charging and isolate them for discharging ✓
C) To convert AC to DC power
D) To act as a main battery disconnect switch
14. The ABYC standard for battery installations requires that a battery be secured against
movement of what angle?
A) 10 degrees in any direction
B) 90 degrees in any direction
C) 45 degrees in any direction
D) 30 degrees in any direction ✓
15. A bilge blower must be rated for what type of service?
A) Ignition protected ✓
B) Waterproof (IP68)
C) Corrosion resistant
D) Explosion proof
16. The maximum allowable voltage drop for a bilge pump branch circuit is:
A) 3%
B) 5%
C) 7%
D) 10% ✓
17. Which of the following is an approved color for a 12V DC positive conductor?
A) White
B) Yellow ✓
C) Green
D) Green/Yellow
18. When sizing a main DC feeder cable from the battery to a distribution panel, the ampacity
must be at least what percentage of the sum of the connected load ampacities?
, A) 100%
B) 115%
C) 125% ✓
D) 150%
19. What is the primary hazard of using an automotive-type battery charger on a marine
battery bank?
A) It charges too slowly.
B) It may not be ignition protected and could cause an explosion. ✓
C) It cannot reach a full state of charge.
D) It uses the wrong voltage.
20. A GFCI (Ground Fault Circuit Interrupter) is required on a boat for which of the following?
A) All 12V DC outlets
B) 120V AC outlets in the head, galley, machinery spaces, and on deck ✓
C) The main AC shore power inlet
D) The battery charger circuit
21. The shore power galvanic isolator or isolation transformer is intended to prevent:
A) AC short circuits
B) DC stray current corrosion from other boats in the marina ✓
C) Overloading the shore pedestal
D) Lightning strikes
22. Which statement about wire size is true?
A) A larger AWG number indicates a larger diameter conductor.
B) Voltage drop is the primary concern for sizing DC conductors. ✓
C) Conductor insulation color determines its minimum ampacity.
D) The length of the circuit has no bearing on conductor size.
23. To minimize voltage drop in a long circuit, you should:
A) Increase the conductor size. ✓
B) Decrease the conductor size.
C) Increase the circuit voltage.
D) Add a capacitor in series.
24. The ABYC standard for AC system color coding states that the equipment grounding
conductor should be:
A) White
B) Green or Green/Yellow ✓
