ABYC Marine Electrical study plan

Calculate unknown current, voltage, resistance, and power in series, parallel, and series-parallel DC circuits using Ohm's law, Kirchhoff's voltage and current laws, and P = IE, showing every step for 20 practice circuits.

Convert between AWG sizes and circular mils, then compute conductor resistance and voltage drop from length, gauge, and conductor material for at least 10 marine-relevant examples.

Explain the relationships among current, potential difference, resistance, and power, and predict how adding loads in parallel changes total current draw and voltage drop on a shared feeder.

Describe how temperature, connection resistance, and corrosion affect resistance in marine DC circuits, and identify the symptoms of a high-resistance connection in a live circuit.

Compare flooded lead-acid, AGM, gel, and lithium iron phosphate batteries on charge voltage profile, depth-of-discharge tolerance, maintenance, and installation constraints, and match each to correct charger settings.

Size a battery bank in amp-hours and kilowatt-hours for a stated daily load and days of autonomy, applying a realistic depth-of-discharge limit, then verify the result against a stated recharge-time target.

Specify the installation requirements for a battery bank: enclosure security and ventilation, terminal protection, cable gauge and length, and the location and rating of the main overcurrent device relative to the battery positive terminal.

Explain the sequence and purpose of bulk, absorption, and float charging stages, and describe how regulators, combiners, echo chargers, and isolation diodes divide charge among banks.

Identify the safety hazards of battery work, including hydrogen gas, acid handling, short-circuit energy, and the correct personal protective equipment for each task.

Select conductor gauge for a stated load and round-trip length using ampacity limits together with the 3% voltage-drop guideline for critical circuits and the 10% limit for non-critical circuits, documenting which criterion controls each choice.

Determine the correct rating and location of overcurrent protection for main, branch, and panel circuits, including the requirement that the main device be within a short distance of the battery source and the recognized exceptions.

Diagram a DC distribution panel showing main breaker, branch breakers, positive and negative bus bars, grounding point, and load labeling, and explain why circuits are grouped as they are.

Apply accepted wiring methods: support intervals, chafe protection, drip loops, termination methods, and the ABYC conductor color conventions for DC positive, negative, and grounding conductors.

Explain how to separate and route DC conductors away from AC and high-current conductors and why physical separation and strain relief matter in a wet, vibrating environment.

Trace the full shore power path from dock pedestal to branch circuits: inlet, cordset, main breaker, equipment leakage circuit interrupter, isolation transformer or galvanic isolator, and panel, naming the function of each component.

Distinguish the grounded conductor from the grounding conductor and explain why neutral-to-ground bonding is made only at the source and never on board while connected to shore power.

Calculate load distribution across a 120/240 V split system and select shore cord, inlet, and main breaker ratings that match the pedestal supply and the vessel's total connected load.

State the trip thresholds and required locations for ground fault circuit interrupters and equipment leakage circuit interrupters, and describe how each responds to a fault in wet locations.

Explain the grounding and neutral-bonding requirements for onboard AC generation, including where the bond is made and how a transfer switch must handle neutral and grounding conductors when switching between sources.

Describe the AC grounding and neutral-bonding requirements for inverter/chargers and identify the failure modes created by an unbonded or double-bonded system.

Compare sacrificial anode cathodic protection with impressed-current systems, select anode material and mass for a stated hull and running-gear configuration, and explain what bonded versus isolated underwater metals means for corrosion.

Distinguish the bonding system, the DC negative return, the AC safety ground, and the lightning protection system, and state the conductor size and connection point expected for each.

Describe a lightning protection system's air terminal, main conductor, and grounding path, and list the precautions that reduce side-flash damage to electronics.

Diagnose open-circuit, short-circuit, high-resistance, and ground-fault conditions using a digital multimeter, writing the meter settings, expected readings, and decision points for each test.

Measure and interpret voltage drop across a loaded circuit and across individual connections to locate a fault, and explain why a voltage reading taken with no load can be misleading.

Specify overcurrent protection and conductor sizing for DC motor and starter circuits, accounting for locked-rotor current and conductor ampacity under engine-room temperature conditions.

Explain inverter and generator selection: continuous versus surge rating, efficiency losses, idle draw, and the sizing margin needed for inductive motor loads.

Describe a systematic troubleshooting sequence for a dead branch circuit and for a charging system that underperforms, listing the checks in the order they should be performed.

Rank all six domains by accuracy from recorded practice results and build a remediation list prioritized by point value and error frequency.

Re-study the two weakest domains using worked examples, re-solving every missed item without reference material before checking the answer.

Complete a timed 60-question mixed practice exam under exam conditions with no notes, then classify every error as knowledge gap, calculation slip, or misread question.

Practice the numeric skills that carry across domains, such as voltage drop, amp-hour sizing, and load balance, until each can be completed accurately without consulting a formula sheet.

Complete two full-length timed practice exams on separate days and score at least 85% on the second.

Review every missed or guessed item from both exams and write the governing rule, the calculation, and the trap that caused the error.

Reproduce from memory the formulas, conductor and overcurrent tables, and grounding rules most likely to be tested, then verify each against reference material and correct discrepancies.

Rehearse the bonding and grounding distinctions one final time, since those errors are the most common cause of missed items in the final week.