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ABYC Marine Electrical Certification
Exam Review
How often (in inches) shall wire bundles be supported? - Answers -Every 18 inches. What type of clamps are to be used for supporting wire bundles when routed over engines and machinery? - Answers -Insulated Metallic Hanger Clamps What tensile force must a 10 Gauge crimp connector withstand for one minute? - Answers -40 lbs (E-11 Table XV) What is the max allowed unsupported cable length for battery cables? - Answers - inches T or F: Running AC and DC conductors together is allowed so long as the AC conductors are sheathed. - Answers -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 - Answers -C. Unwanted open The primary by-product of excessive electrical resistance is: A. Increased Amperage B. Increased Voltage C. Reduced Ambient Temperature D. Heat - Answers -D. Heat One HP = how many watts? - Answers -1 HP = 746 Watts What is the preferred tool for tracing shorted and open circuits? A. Ohm meter B. Amp clamp C. Volt meter D. TDR (time-domain reflectometer) - Answers -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)? - Answers -0 AWG
DC grounded conductors on new boats that are also equipped with AC systems should use what color insulated wire? - Answers -Yellow What is the smallest guage wire allowed for unsheathed wire runs through the boat? - Answers -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. - Answers -False. Start batteries have a greater number of thinner plates within each cell. Which type of battery generally recharges faster? Deep cycle or cranking? - Answers - Cranking What tool and common household staple are used to clean battery terminals? - Answers -Wire brush and backing soda. Why might a fully-discharged wet-cell type battery freeze? - Answers -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? - Answers -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? - Answers - True What provision must be in place on any fuel line located within 12 inches of a battery terminals? - Answers -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) - Answers -80 F, 25 Amps, 10.5 Volts According to ABYC, what is the minimum battery reserve capacity? - Answers - 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). - Answers -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). - Answers -0 degrees F, 30 seconds, 7.2V
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% - Answers -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. - Answers -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? - Answers -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? - Answers -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? - Answers -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? - Answers -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? - Answers - inches or more (unless waterproof!) How far away from a gasoline tank must a pre-wired battery charger's AC connection plug be located? - Answers -At least 24 inches T or F: All marine inverters shall utilize an internal or external GFCI on their AC outlets. - Answers -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 - Answers -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) - Answers -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? - Answers -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? - Answers - Tech A According to ABYC, what is the maximum distance allowed between a boat's shore power connection and the main overcurrent protection device? - Answers -10' What is an ELCI and where is it required to be installed? - Answers -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. - Answers -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? - Answers -At least 135% of isloator's nominal rating. (A-28.11.1) What is the general rule for use of friction connectors? - Answers -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? - Answers -> 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 - Answers -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 - Answers -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. Faulty output circuit breaker D. Excessively high DC voltage supply - Answers -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 - Answers -A. Tech A T or F: metal AC panel boards must be grounded. - Answers -True T or F: Boats that have an inverter installed must have a warning label noting such at the main electrical panel - Answers -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? - Answers -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? - Answers -75 C (167 F) (E-11.14.1.1.3) What is the minimum voltage rating for all DC conductors? - Answers -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 - Answers -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 - Answers -True (E- 11.14.1.3.7.2) 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 - Answers -B. Tech B The maximum allowable voltage drop permitted for panel board DC feeders is: A. 2%
B. 3%
C. 10%
D. 15% - Answers -B. 3% T or F: Solid (non-stranded) conductors are not allowed for AC wiring anywhere on a boat. - Answers -True T or F: magnetic transformers with integrated secondary-side overcurrent protection and automatically resetting thermal overload protection are ABYC compliant. - Answers - 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 - Answers -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 - Answers -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 - Answers -D. TDR High frequency transformers typically run _____ than traditional magnetic transformers. A. Cooler B. Hotter C. Faster D. Slower - Answers -A. Cooler What is the pull-test requirement for DC plug/receptacles? - Answers -6 lbs for 1 minute (E-11.13.2.3) T or F: For AC wiring, the "hot" ungrounded conductor (i.e., not the insulation color) should be brass or copper colored and the "neutral" grounded conductor should be light silver colored. - Answers -True For a branch circuit supplying both receptacle loads and permanently connected loads, what is the maximum recommended permanent load for 15-amp circuit? For 20-amp
Name two likely possible causes of falsely trigger fire alarm in an engine room space. - Answers -Excessive humidity, low supply voltage T or F: boats with an enclosed accommodation compartment shall have an audible high bilge-water alarm. - Answers -True What gauge wire is required at a minimum for the primary down conductor from a lightning Air Terminal? - Answers -4 AWG What is the minimal required surface area for lightning protection system's immersed ground plate? - Answers -1 sq. ft. What gauge wires is required for lightning protection system secondary conductors? - Answers -6 AWG What is the maximum allowable trip current & time for ELCI/RCD at the main shore power input? - Answers -30 mA, 100 ms T or F: CO detectors will also detect smoke in most situations. - Answers -False For true RMS inverters what is the relationship between peak and RMS voltage? - Answers -Peak Voltage = 1.414 * RMS Voltage or, V peak * .707 = V RMS What is the max typically allowable % difference between true sinusoidal peak AC voltage and harmonically distorted peak AC voltage? - Answers -2-3% 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? - Answers -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 - Answers -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 - Answers -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 - Answers -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. - Answers -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 - Answers -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 - Answers -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" - Answers -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
c. 285 d. 330 - Answers -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 - Answers -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 - Answers -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 " - Answers -c. 6 " (A-31.6.1) What is a possible problem with installing a new solid state Voltage regulator to replace a manual one? a. Overcurrent protection will have to match new amperage draw from device. b. There could be severe radio interference from the new device. c. Reverse influx could result, and diodes will have to be installed to modify voltage flow. d. None of the above - Answers -b. There could be severe radio interference from the new device. (T or F) Impedance can be defined as the total resistance flow in a D.C. system - Answers -F (impedance refers to AC systems) When installing a starter over current protection must be within inches of the battery. A. 7" B. 40" C. 72" D. None of the above - Answers -D. None of the above A neutral safety switch is used for:
a. Safely switching between forward and reverse without damaging transmission b. Not allowing the engine to start with gear in neutral c. Safely allowing someone to be in the water (like skier) without risk of propeller strike d. Not allowing the engine to start when not in neutral - Answers -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 - Answers -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 - Answers -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 - Answers -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 - Answers -d. 4 Each installed battery shall not move more than one inch in any direction when pulling force of ______ lbs or twice battery weight is applied. a. 60 b. 70 c. 80 d. 90 e. 100 - Answers -d. 90 Multi wire plugs and receptacles used in conjunction with harness type wiring systems shall incorporate means except: a. wire nuts b. molded connectors c. insulation grips d. extended terminal barrels e. all the above - Answers -a. wire nuts
c. 10 amps d. 5 amps - Answers -b. 0 amps The minimum space for conductor runs near water-cooled enigine exhaust is a. 1" b. 2" c. 4" d. 9" - Answers -b. 2" (E-11.14.4.1.6) T or F: if power disconnect switch is in excess of 10 feet, over-current protection is required - Answers -True Tech A says that combined AC/DC panels boards are grounded via the DC negative bus. Tech B says that the panel board should be grounded to the AC grounding bus. Which tech is correct? a. Technician A b. Technician B c. Neither A nor B d. Both A and B - Answers -b. Technician B An electrical diode is a component that: a. Is found in alternators b. Is found in galvanic isolators c. Is found in battery isolators d. All of the above are correct - Answers -d. All of the above are correct 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) - Answers -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 - Answers -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. - Answers -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 - Answers -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. - Answers -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 - Answers -c. 30 W A branch circuit for DC power can have overcurrent protection not to exceed _____ of conductor ampacity. a. 125% b. 135% c. 150% d. Not required - Answers -c. 150% (see 11.10.1.5.2) When combining batteries in DC installation, which statement is NOT true. a. two 12 volt batteries connected in series will give 24 volts. b. two 12 volt batteries connected in parallel will give 12 volts c. When connected in series, AmpHrs is increased. d. When connected in series, AmpHrs stays the same. - Answers -c. When connected in series AmpHrs is increased. On a vessel with 1 charging source ABYC requires sustaining DC loads for _____ minutes: a. 30 b. 60 c. 90 d. 120 - Answers -c. 90 minutes A customer has a 600 Ah 'house' battery bank and wants to recharge with the highest amperage (standard flooded batteries are being used). How high amperage is reasonable? a. 200 amps b. 150 amps c. 100 amps d. 50 amps - Answers -b. 150 amps (25% of capacity) While out cruising (away from the dock), batteries on a typical cruiser have what percentage of charge? a. 0 - 100%
When grounding an electrical propulsion system you should always remember too... a. Isolate the grounding system from the main ship grounding system. b. Install a blocking diode between it and your main ground bus. c. Tie your ground into your bonding system. d. Combine it with your main grounding system. - Answers -a. Isolate the grounding system from the main ship grounding system. (see E-30.5.2) Of the following which is NOT a correct way of testing a battery. a. Use a load tester b. Keep track of amps going in and out with an amp hour meter c. Checking voltage drop when engaging starter motor d. Measure open circuit voltage - Answers -c. Checking voltage drop when engaging starter motor (Calder p. 78) The minimal battery reserve capacity in minutes for a supplied battery power, based on ABYC. A. 30 min B. 90 min C. 120 min D. 200 min - Answers -B. 90 min A gassing battery gives off: a. sulfuroxide b. nitrous oxide c. nitrogen d. hydrogen - Answers -d. hydrogen A fully charged battery, at rest will have a voltage of: a. 12. b. 11. c. 12. d. 13.2 - Answers -c. 12. Some battery manufactures will only consider warranty claims on batteries whose condition has been determined by use of a a. Conductance tester b. Load tester c. Hydrometer d. Megohmmeter - Answers -a. Conductance tester When two 6 volt, 220 amp/hour golf cart batteries are connected in series, the resulting output is: a. 6 volt, 440 amp/hr b. 6 volt, 220 amp/hr c. 12 volt, 440 amp/hr d. 12 volt, 220 amp/hr - Answers -d. 12 volt, 220 amp/hr
When two 6 volt, 220 amp/hour golf cart batteries are connected in parallel, the resulting output is: a. 6 volt; 220 amp/hr b. 12 volt, 220 amp/hr c. 6 volt, 440 amp/hr d. 12 volt, 440 amp/hr - Answers -c. 6 volt, 440 amp/hr A deep cycle battery is one with an internal design that suits: a. low amperage long term discharge b. high amperage long term discharge c. low amperage short term discharge d. high amperage short term discharge - Answers -a. low amperage long term discharge What household item is used to neutralize battery acid? a. WD 40 b. Baking Powder c. Bleach d. Baking Soda - Answers -d. Baking Soda The maximum allowable voltage drop permitted for panelboard DC feeders based on ABYC is: A. 2% B. 3% C. 10% D. 12% - Answers -B. 3% Which of the following battery has the largest case or physical size of the battery case? a. Group 24 b. Group 4D c. Group 31 d. Cannot determine without knowing the CCA - Answers -b. Group 4D T or F: It is ok to combine different types of batteries as long as they are all of the lead- acid type (i.e. Gell Cell, SLA, AGM, Etc.) - Answers -False When simultaneously recharging two different types of batteries (house & start) with diode type battery isolator, where is it best to sense the voltage for charging source? a. On the deep-cycle side b. On the cranking battery side c. Sense both together d. Either side, does not matter - Answers -a. On the deep-cycle side When troubleshooting a charging problem with a voltage regulator, a technician should find the brown wire: a. To provide AC signal for the tachometer
