ABYC
ABYC Marine Electrical Certification Exam
Questions with Correct Verified Answers,
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T or F: A battery charger case shall be tied to the DC negative output
terminal at the battery charger. - ANS ✓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? - ANS ✓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? - ANS ✓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? - ANS ✓Class T fuse rated
for appropriate AIC
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What may happen to a solar array or wind generator used to charge
batteries without a blocking diode? - ANS ✓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? -
ANS ✓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? - ANS ✓At least 24 inches
T or F: All marine inverters shall utilize an internal or external GFCI
on their AC outlets. - ANS ✓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 - ANS
✓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) - ANS ✓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? - ANS
✓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? - ANS ✓Tech A
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According to ABYC, what is the maximum distance allowed between a
boat's shore power connection and the main overcurrent protection
device? - ANS ✓10'
What is an ELCI and where is it required to be installed? - ANS
✓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.
- ANS ✓False, they must be isolated to prevent shock hazard at the
unutilized shore power connector pins.
What ampacity is required for wire and terminals connecting a
galvanic isolator? - ANS ✓At least 135% of isolator’s nominal rating. (A-
28.11.1)
What is the general rule for use of friction connectors? - ANS
✓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? - ANS ✓> 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
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C. Be connected to the engine common positive terminal or its bus
D. Be tied to the battery isolator - ANS ✓B. Not be grounded on the boat
If a customer complains about receiving shocks from her boat when
shore power is active, the technician should first test:
A. Polarity check of shore cord
B. Polarity check of the battery system
C. Current Leakage Test
D. Converter voltage check - ANS ✓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 - ANS ✓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 - ANS ✓C. An open neutral
What is a likely cause of non-functioning galvanic isolator?
ABYC Marine Electrical Certification