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ABYC Marine Electrical Certification Exam 2025 |
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Voltage drop could be used to test for a bad starter cable. To test the cable a technician would use the DVOM and check voltage at what two points? a. At both ends of the cable b. The battery terminals c. The positive cable at starter and engine block (ground) d. At the starter solenoid and engine block (ground) ---------CORRECT ANSWER----- ------------a. At both ends of the cable An ampere is a measurement of: a. Power b. Resistance c. Potential to do work d. Current Flow ---------CORRECT ANSWER-----------------d. Current Flow T or F: On an AC and DC combined panel that it affixed with screws, the energized AC parts on the back of the panel must be covered. ---------CORRECT ANSWER------ -----------True.
What is the best way to prevent corrosion on a battery cable a. Use WD 40 b. Use corrosion block c. Heat shrink the entire battery post d. Use pure copper lugs ---------CORRECT ANSWER-----------------b. Use corrosion block T or F: A shunt is a conductor of known resistance placed in series with a circuit to indicate current flow by measurement of the voltage drop across this conductor. - --------CORRECT ANSWER-----------------True A light circuit uses a 12 volt battery to power a bulb which uses 2.5 amps of power. How many watts Is the light bulb? a. 10 W b. 20 W c. 30 W d. 40 W ---------CORRECT ANSWER-----------------c. 30 W A branch circuit for DC power can have overcurrent protection not to exceed _____ of conductor ampacity. a. 125% b. 135%
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" In a series circuit, the more resistive loads you add: a. The total voltage will increase b. The total current will increase c. The total voltage will decrease d. The total current will decrease ---------CORRECT ANSWER-----------------d. The total current will decrease The maximum number of terminals to be attached to any one terminal stud based on ABYC Standard is: a. 1 b. 2 c. 3 d. 4 ---------CORRECT ANSWER-----------------d. 4 What does "trip free" circuit breaker mean? a. The breaker is inexpensive
a. 35 amps b. 24.5 amps c. 20.8 amps d. none of the above ---------CORRECT ANSWER-----------------b. 24.5 amps T or F: Pigtails less than 7 inches (175mm) in length are exempt from overcurrent protection requirements. ---------CORRECT ANSWER-----------------True Allowable amps less than 50 volts (not bundled). You have a cable that runs from a battery to a bow thruster. All components are in the forward cabin. The wire is good 105 C rated #0 AWG. How many amps can safely pass through that cable? a. 200 b. 242. c. 285 d. 330 ---------CORRECT ANSWER-----------------c. 285 Pigtails less than 7 inches (175mm) in length are exempt from overcurrent protection requirements. A pigtail is defined as: a. A factory molded cord set for shorepower. b. A length of wire (less than 7") installed by technician to a piece of electronic equipment c. The factory wiring attached to a bilge pump -
d. A factory installed length of wire included with a piece of equipment --------- CORRECT ANSWER-----------------d. A factory installed length of wire included with a piece of equipment in a parallel circuit, the more resistive loads you add: a. The total voltage will increase b. The total current will increase c. The total voltage will decrease d. The t o t a l current w i l l decrease ---------CORRECT ANSWER-----------------b. The total current will increase Strain relief shall be provided for all wiring passing through the battery charger case to relieve strain on terminals, splices or internal wiring. Unless a strain relief method is integral with the case for wiring passing through, a means to achieve strain relief shall be installed within inches of the case. a. 3 " b. 5 " c. 6 " d. 10 " ---------CORRECT ANSWER-----------------c. 6 " (A-31.6.1) What is a possible problem with installing a new solid state Voltage regulator to replace a manual one?
d. Not allowing the engine to start when not in neutral ---------CORRECT ANSWER-- ---------------d. Not allowing the engine to start when not in neutral A successful customer experience includes: a. Being neat and prompt b. Asking question to verify a complaint c. Listening to the customer d. All of the above ---------CORRECT ANSWER-----------------d. All of the above In the formula for circular mils, for our purposes "K" is equal to 10.75. What does this number represent? a. The wire thickness b. The resistivity of copper c. The rating of the wire insulation d. Black Magic ---------CORRECT ANSWER-----------------b. The resistivity of copper All of the following could cause a conductor to overheat except. a. Undersize conductor b. Excessive amperage c. Insulation temperature rating too low d. Corroded connection ---------CORRECT ANSWER-----------------c. Insulation temperature rating too low
How many conductors may be attached to a single terminal stud? a. 1 b. 2 c. 3 d. 4 ---------CORRECT ANSWER-----------------d. 4 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
C. Volt meter D. TDR (time-domain reflectometer) ---------CORRECT ANSWER-----------------D. TDR (time-domain reflectometer) A technician is installing a cable run from the batteries to the main DC panel board on a boat as part of a refit. The boat has a 12-volt system and the distance form the panel to the batteries is 15 ft. The maximum current draw from the panel is calculated at 90 amps. What guage cable should be used (minimum)? ----- ----CORRECT ANSWER-----------------0 AWG DC grounded conductors on new boats that are also equipped with AC systems should use what color insulated wire? ---------CORRECT ANSWER----------------- Yellow What is the smallest guage wire allowed for unsheathed wire runs through the boat? ---------CORRECT ANSWER-----------------16 AWG 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
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. What is the minimum ampere interrupting capacity (AIC) for main overcurrent protection on a battery bank rated at 12 V, 1500 CCA? ---------CORRECT ANSWER-- ---------------AIC = 5000 Amps (E-11 table IV-A) What is the minimum ampere interrupting capacity (AIC) for main overcurrent protection on a battery bank rated at more than 2200 CCA or more than 500 Ahr? ---------CORRECT ANSWER-----------------AIC = 2X mnfg's short-circuit rating or 100X nominal Ahr rating. T or F: it is ok to mount a battery switch inside an engine room, because ABYC startes that it must be located as close to the batteries as practical. --------- CORRECT ANSWER-----------------False. "Readily accessible" defines entry into the engine room in an emergency as dangerous - use a remote battery switch. Explain the "7- 40 - 72" rule ---------CORRECT ANSWER-----------------Overcurrent protection must be located withing 7 inches of the power source unless contained within a sheath, in which case it may be up to 40 inches away. If the power source is a battery and the conductors are sheathed, OC may be up to 72 inches away.
What does "trip free" breaker mean? ---------CORRECT ANSWER----------------- Resetting mechanism cannot overrid over current interrupting mechanism. (Note: some residential breakers are not trip free) The maximum sustained charging voltage acceptable to some gell cell battery manufacturers is: 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)
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!) How far away from a gasoline tank must a pre-wired battery charger's AC connection plug be located? ---------CORRECT ANSWER-----------------At least 24 inches
T or F: All marine inverters shall utilize an internal or external GFCI on their AC outlets. ---------CORRECT ANSWER-----------------False. (only when installed in location that required GFCI per ABYC E-11) T or F: most GFCI outlets can be used in a gasoline engine room ---------CORRECT ANSWER-----------------False. Most are not ignition protected. T or F: Because the shore power connection is a power source, the neutral conductor should be tied to ground at the point where it comes in to the boat (shore power cable connection) ---------CORRECT ANSWER-----------------False. Shore power neutral is tied to ground on the shore side. Tech A says that voltage supplied to the rotor controls the alternator output voltage. Tech B says that the alternator output is proportional to the rotor voltage. Which is correct, A, B, Both or Neither? ---------CORRECT ANSWER----------- ------Both. Tech A says that AC and DC are able to run together down the same conductor. Tech B says this is technically impossible. Which is correct, A, B, neither or both? - --------CORRECT ANSWER-----------------Tech A
