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ABYC MARINE ELECTRICAL
CERTIFICATION EXAM 2024 | ALL
QUESTIONS AND CORRECT ANSWERS |
ALREADY GRADED A+ | LATEST VERSION
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The A says the a faulty circuit breaker could require an overhaul. Tech B says that circuit breakers used in recreational marine applications must be replaced if found defective. Who's right? A. Tech A B. Tech B C. Both may be correct, depending on circumstances D. Neither ------CORRECT ANSWER---------------B. Tech B The maximum allowable voltage drop permitted for panel board DC feeders is: A. 2% B. 3% C. 10% D. 15% ------CORRECT ANSWER---------------B. 3% T or F: Solid (non-stranded) conductors are not allowed for AC wiring anywhere on a boat. ------CORRECT ANSWER---------------True T or F: magnetic transformers with integrated secondary-side overcurrent protection and automatically resetting thermal overload protection are ABYC compliant. ------CORRECT ANSWER---------------False. Auto-reset is not allowed.
To test a 120V AC element in a hot water heater, the tech may run a _____ test. A. Voltage B. Capacitance C. Continuity D. Inductance ------CORRECT ANSWER---------------C. Continuity All terminations and junctions for AC conductors must be installed: A. in free air to allow for proper ventilation B. Inside an enclosure requiring the use of hand-tools to open C. In conduit D. In snap-covered junction boxes ------CORRECT ANSWER---------------B. Inside an enclosure requiring the use of hand-tools to open Wha is the best tool to use for locating short-circuits? A. Megger B. Amp Clamp C. DVM D. TDR ------CORRECT ANSWER---------------D. TDR High frequency transformers typically run _____ than traditional magnetic transformers. A. Cooler B. Hotter C. Faster D. Slower ------CORRECT ANSWER---------------A. Cooler What is the pull-test requirement for DC plug/receptacles? ------CORRECT ANSWER---------------6 lbs for 1 minute (E-11.13.2.3)
For how long must a motor be able to sustain a locked rotor condition without inducing a fire hazard? ------CORRECT ANSWER---------------seven hours (E-11.10.1.3.1) T or F: if no standard rating OC protection device is available which equals 100% of the allowable current for the conductor being protected, the next larger rating, up to 150% of the conductor ampacity, may bee used - unless the load is a motor. ------CORRECT ANSWER---------------True Describe why a non-functional tachometer and charging system on a diesel engine may be caused by a failed oil pressure sending unit. ------ CORRECT ANSWER---------------On diesels, the oil pressure sender may be used to switch alternator on/off and the trigger the tachometer. True or False: AC receptacles may be used for DC service, provided they are properly labeled. ------CORRECT ANSWER---------------False Tech A says that combined AC/DC panel boards are grounded via the DC negative bus. Tech B says that such panel boards should be grounded to the AC grounding bus. Which tech is right? A. Tech A B. Tech B C. Both techs are correct D. Neither tech is correct ------CORRECT ANSWER---------------B. Tech B Start-in-gear protection switches should be open or closed when in neutral? ------CORRECT ANSWER---------------Closed when in neutral (therefore, an open-circuit failure would prevent engine starting)
How often (in inches) shall wire bundles be supported? ------CORRECT ANSWER---------------Every 18 inches. What type of clamps are to be used for supporting wire bundles when routed over engines and machinery? ------CORRECT ANSWER--------------- Insulated Metallic Hanger Clamps What tensile force must a 10 Gauge crimp connector withstand for one minute? ------CORRECT ANSWER---------------40 lbs (E-11 Table XV) What is the max allowed unsupported cable length for battery cables? ------ CORRECT ANSWER---------------36 inches T or F: Running AC and DC conductors together is allowed so long as the AC conductors are sheathed. ------CORRECT ANSWER---------------True The most common electrical circuit problem in marine applications is: A. Short circuits B. Too much continuity C. Unwanted open D. Inter circuit Short ------CORRECT ANSWER---------------C. Unwanted open The primary by-product of excessive electrical resistance is: A. Increased Amperage
T or F: Compared to deep cycle (house) batteries, cranking batteries will have thicker lead plates to facilitate the higher, short-duration current draws. ------CORRECT ANSWER---------------False. Start batteries have a greater number of thinner plates within each cell. Which type of battery generally recharges faster? Deep cycle or cranking? - -----CORRECT ANSWER---------------Cranking What tool and common household staple are used to clean battery terminals? ------CORRECT ANSWER---------------Wire brush and backing soda. Why might a fully-discharged wet-cell type battery freeze? ------CORRECT ANSWER---------------Most of the sulfuric acid has been absorbed into the lead plates, leaving mostly water in the electrolyte. Batteries must be secured to prevent movement of more than ______ inches in any direction when a pulling force of _____ or _____, whichever is less, is applied through the center of gravity of the battery for how long? - -----CORRECT ANSWER---------------1 inch, 90 lbs or 2x the battery weight, for 1 minute in each direction. T or F: it is ok to install batteries directly below an uninterrupted fuel line? -- ----CORRECT ANSWER---------------True What provision must be in place on any fuel line located within 12 inches of a battery terminals? ------CORRECT ANSWER---------------Must be protected with dielectric insulating material
Define: Battery reserve capacity = the number of minutes that a new, fully charged battery at ______ degrees F can be continuously discharged at ______ amps while maintaining _____ volts (for a 12 v battery) ------ CORRECT ANSWER---------------80 F, 25 Amps, 10.5 Volts According to ABYC, what is the minimum battery reserve capacity? ------ CORRECT ANSWER---------------90 minutes Define: Marine Cranking Amps = the discharge load, in amperes, that a new, fully-charged battery at _____ degrees F can deliver for ______ seconds while maintaining a voltage of _____ volts (for a 12 v battery). -----
- CORRECT ANSWER---------------32 degrees F, 30 seconds, 7.2V Define: Cold Cranking Amps = the discharge load, in amperes, that a new, fully-charged battery at _____ degrees F can deliver for ______ seconds while maintaining a voltage of _____ volts (for a 12 v battery). ------ CORRECT ANSWER---------------0 degrees F, 30 seconds, 7.2V What is the largest guage wire that may be connected to a bettery with wing-nuts? ------CORRECT ANSWER---------------8 AWG Per ABYC E-10, a battery switch must be installed in the positive conductor from each battery bank with a CCA rating greater than ____ (or greater than _____ Ah if CCA rating not available). ------CORRECT ANSWER------- --------800 CCA or 100 Ahr (exceptions: electronic equipment with battery backed memories; safety equipment such as bilge pumps, alarms, CO detectors, bilge blowers; battery chargers; I'm pressed current systems.
A. 13.8 V
B. 14.5 V
C. 14.1 V
D. 13.2 Vll ------CORRECT ANSWER---------------C. 14.1 V When testing a wet-cell battery with a hydrometer, what threshold is used to determine a bad cell? ------CORRECT ANSWER---------------0.050 points of specific gravity below other cells = bad cell. When testing a wet-cell battery with a hydrometer, what reading indicates a fully charged battery? ------CORRECT ANSWER---------------1.260 - 1. (temperature dependent) When testing a fully charged start battery for capacity with a load tester, what % of CCA rating should be induced by the load to test resulting voltage? ------CORRECT ANSWER---------------50% Most engine-driven alternators are optimally spun at what percentage of engine RPMs? A. Between 10% and 50% B. Less than 10% C. Between 150% and 200% D. Greater than 200% ------CORRECT ANSWER---------------C. Between 150% and 200% T or F: A battery charger case shall be tied to the DC negative output terminal at the battery charger. ------CORRECT ANSWER---------------False. the battery charger case shall be tied to the engine negative terminal/bus, along with the negative output terminal of the battery charger, not at the battery charger case itself.,
Why do battery chargers require a separate case connection to main AC grounding bus and Engine negative / DC grounding bus? ------CORRECT ANSWER---------------In case of an internal short to the case, the AC grounding wire would not carry enough current. What is the minimal wire size required for a battery charger case connection to DC ground/engine negative? ------CORRECT ANSWER------- --------No smaller than 1 size below the DC current carrying conductors between the charger and batteries - provided OC protection on positive DC output is no greater than 135% of DC grounding cable ampacity and conductor is no smaller than 16 AWG. What device is typically found to satisfy the required OC protection between a battery charger and the batteries? ------CORRECT ANSWER---- -----------Class T fuse rated for appropriate AIC What may happen to a solar array or wind generator used to charge batteries without a blocking diode? ------CORRECT ANSWER--------------- Batteries will feed back into solar array or wind generator coil and discharge (possibly damage). Note: many voltage regulators have integral blocking diodes. How far above bilge water level must a battery charger be mounted? ------ CORRECT ANSWER---------------24 inches or more (unless waterproof!)
What is an ELCI and where is it required to be installed? ------CORRECT ANSWER---------------Equipment Leakage Current Interrupter - within 10 feet of shore power connection unless an isolation transformer is located within 10' of shore power connection. T or F: When more than one option for shore power inlet is installed on a boat, the shore power neutrals shall be tied together on the boat. ------ CORRECT ANSWER---------------False, they must be isolated to prevent shock hazard at the unutilizd shore power connector pins. What ampacity is required for wire and terminals connecting a galvanic islolator? ------CORRECT ANSWER---------------At least 135% of isloator's nominal rating. (A-28.11.1) What is the general rule for use of friction connectors? ------CORRECT ANSWER---------------Ampacity < 20 Amps, voltage drop across terminals < 50 mV @ 20 A flow, no separation with a one-minute pull of 6 lb force. When measuring temperature to determine potential electrical issues involving excessive connector resistance, what is the threshold for concern? ------CORRECT ANSWER---------------> 25 degrees above ambient According to the ABYC, the shore-power grounded conductor should: A. Be connected to the AC neutral B. Not be grounded on the boat C. Be connected to the engine common positive terminal or its bus
D. Be tied to the battery isolator ------CORRECT ANSWER---------------B. Not be grounded on the boat If a customer complains about receiving shocks from her boat when shore power is active, the technican should first test: A. Polarity check of shore cord B. Polarity check of the battery system C. Current Leakage Test D. Converter voltage check ------CORRECT ANSWER---------------A. Polarity check of shore cord A customer is complaining about low-voltage at the AC panel. What should you do first? A. Re-calibrate the panel meter B. Check the voltage at the dock pedestal C. Check the polarity indicator D. Replace the overcurrent device ------CORRECT ANSWER---------------B. Check the voltage at the dock pedestal A customer notes a reverse-polarity problem. All of the following are likely causes, except: A. Improperly wired shore power cord B. Improperly wired shore power inlet receptacle C. An open neutral D. Reversal of the hot and neutral conductors in the AC panel feeder cable ------CORRECT ANSWER---------------C. An open neutral What is a likely cause of non-functioning galvanic isolator? A. a shorted isolator diode B. Improper current rating of the isolator diode C. An on-board neutral-to-ground connection
On a brushless generator, a possible cause for low AC voltage output under load could be: A. High engine RPM B. Faulty exciter winding / diode rectifier circuit C. Faulty output circuit breaker D. Excessively high DC voltage supply ------CORRECT ANSWER------------- --B. Faulty exciter winding / diode rectifier circuit Tech A says the ABYC has pull-test requirement for wiring connecting the generator to onboard circuits. Tech B says pull-test requirements are dictated by the generator manufacture. Which one is correct? A. Tech A B. Tech B C. Both Techs D. Neither Tech ------CORRECT ANSWER---------------A. Tech A T or F: metal AC panel boards must be grounded. ------CORRECT ANSWER---------------True T or F: Boats that have an inverter installed must have a warning label noting such at the main electrical panel ------CORRECT ANSWER------------ ---True What must be true of a sub-panel input circuit breaker's rating such that the main breaker may be sized up to 150% of the sub-panel feeder conductor's ampacity? ------CORRECT ANSWER---------------The sub-panel breaker's trip point shall be no greater than 100% of the total current draw for the entire sub-panel.
What is the minimum insulation temperature rating for conductors routed inside an engine room? ------CORRECT ANSWER---------------75 C (167 F) (E-11.14.1.1.3) What is the minimum voltage rating for all DC conductors? ------CORRECT ANSWER---------------50 VDC (E-11.14.1.2.1) When multiple DC conductors are bundled together for a distance of greater than ____ inches, the allowable ampacity of each conductor must be derated based on the table found within standard E- 11 ------CORRECT ANSWER---------------24 inches (E-11.14.1.3.7.1) T or F: The AC grounding conductor shall be permitted to be one size smaller than the current carrying conductors on circuits rated greater than 30 Amps ------CORRECT ANSWER---------------True (E-11.14.1.3.7.2) Name three common gasses other than CO that may trigger a CO alarm: -- ----CORRECT ANSWER---------------Styrene from curing fiberglass, methane from head/holding tank, hydrogen from battery outgassing or refrigeration leaks Name two likely possible causes of falsely trigger fire alarm in an engine room space. ------CORRECT ANSWER---------------Excessive humidity, low supply voltage T or F: boats with an enclosed accommodation compartment shall have an audible high bilge-water alarm. ------CORRECT ANSWER---------------True
On a standard 3-conductor AC outlet, which of the two blade conductors (i.e., not the rounded GROUNDING conductor) is Hot and which is Neutral? ------CORRECT ANSWER---------------shorter, thicker terminal is HOT taller, narrower terminal is NEUTRAL A polarity indicator light that is glowing more dimly than normal could be an indicator of: A. An open circuit in the neutral to ground link at an AC generator B. An open circuit in the hot wire connection C. A ground connection with very low impedance D. Excessive AC frequency ------CORRECT ANSWER---------------A. An open circuit in the neutral to ground link at an AC generator When using a high-resolution amp clamp on a shore power cord and activating AC circuits one by one, the technician notes that the AC leakage current measured increases with each appliance. This most likely indicates: A. An open-circuit in the grounding conductor on the dock B. Excessively high voltage delivered by the utility company C. Excessive voltage drops in the AC power supply to the boat D. A neutral-to-gound link at the boats AC panel board ------CORRECT ANSWER---------------D. A neutral-to-gound link at the boats AC panel board A system voltmeter shall be installed on the main panel board if the system is permanently connected to: A. Inverter B. Generator C. Motor D. B & C above E. All of the above ------CORRECT ANSWER---------------E. All of the above
Two techs are rewiring an old sailboat. Tech A says they should use all series circuits to keep the wiring clean and simple. Tech B says series circuits should only serve a single load. Who is correct? a. Tech A b. Tech B c. Both are right. d. Neither are right. ------CORRECT ANSWER---------------d. Neither are right. According to ABYC, maximum current carrying capacity of a 10 gauge wire, 105 degree C insulation, inside the engine room when bundled with 2 other current carrying wires would be? a. 60 amps b. 51 amps c. 42 amps d. 35.7 amps ------CORRECT ANSWER---------------d. 35.7 amps What is the expected voltage across a 'closed' switch that is operating properly a. It should read current battery voltage b. It can be up to 10% less than battery voltage c. It should read '0' VDC d. Not enough information provided ------CORRECT ANSWER---------------c. It should read '0' VDC Sheathed ungrounded conductors connected directly to a battery must have overcurrent protection devices located within inches of the connection to the battery. a. 7 " b. 36" {slightly less than 1 meter) c. 40 " d. 72" ------CORRECT ANSWER---------------d. 72"
