ABYC Air Conditioning & Refridgeration Certification
Exam Review UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
Absolute Humidity The weight of water vapor in a given amount of air (Grains per cubic foot)
Absolute Pressure Pressure measured with a base of zero
Absolute Temperature A temperature scale using absolute zero as a reference - Rankin or Kelvin Scale
(may be measures in degrees C or F)
Absolute Zero Theoretical temperature at which all molecular activity ceases = -273.16 C or
-456.69 F
250% By approximately how much (%) does a start capacitor increase motor torque?
C. Both Tech A says that it is possible to identify the start and run windings of a motor
with an ohm meter by noting which has higher resistance, indicating the start
windings. Tech B say the highest resistance will be noted when measuring from
run to start terminals. Which is correct?
A. Tech A
B. Tech B
C. Both
D. Neigher
Compressor The heart of a system, keeps the refridgerant flowing at specific rates of flow, at
specific temperatures.
Inlet (suction), shuts down system if pressure drops too On which side of a compressor is the low pressure switch, inlet or outlet, and
low. what function does it provide?
Outlet, shuts down compressor if pressure gets too On which side of a compressor is the high pressure switch, inlet or outlet, and
high (to protect the compressor). what function does it provide?
Condenser Air or water cooled heat exchanger which absorbs latent heat energy of hot
refridgerant gas and causes it to become a liquid.
Metering Device (AKA Expansion Device/Tube/Valve, Maintains a specific rate of flow from the high-pressure side of a refridgeration
TXV, or Capillary Tube) system into the low-pressure side.
Evaporator Air heat-exchanger that allows heat from incoming air to pass into the cold
refridgerant liquid which absorbs latent heat and evaporates in the process,
cooling the exit air.
KLIXON overload protector Trademark for a popular manufacturer of compressor overload protector
device. (Also manufactures overcurrent protection devices, switches, and
thermostats used in HVAC systems)
Running at lower than rated voltage (increases current What is a common cause of motor winding insulation leakage/breakdown?
draw and thus temperature of windings)
, 3.412 BTU's/Hour = 1 Watt 1 Watt is equal to how many BTU's per hour?
1 BTU / hr = 0.293 Watts 1 BTU per hour is equal to how many Watts?
Tech B (motors have PF < 1) When calculating power draw for a motor, Tech A says to multiply Amps by
Volts. Tech B says this is true, but it would be more accurate to include a third
multiplier, Power Factor to give accurate real power draw. Who is most correct?
Potential Relay Another name for Start Relay
return should be 20% bigger than source Ho much bigger should an air conditioning return duct be compared to the
discharge duct?
Waist heigh or higher At what height should A/C discharge ducts be located in the cabin?
low, near the floor At what height should A/C return duct sources be located in the cabin?
risk of CO ingress Why should A/C condensate drain hose not be discharged into the engine
room bilge area?
3 feet What is the minimal distance on the outside of the hull between A/C
condensate discharge outlet and engine exhaust outlet?
5/8 inch What is the minimum diameter recommended for A/C condensate drain hose?
increased suction causing low-pressure switch What are some possible manifestation from an overly dirty A/C air filter?
activation or tripped circuit breaker
True T or F: although ABYC does not require double hose clamping on thru-hull
seacocks, ISO standards and many manufacturer's do recommend it.
48 inches What is the max distance between support clamps for refrigerant piping?
B. Leaking gasket in sea strainer A technician notices air bubbles visible through the clear section of a raw-water
sea strainer. What is the most likely cause?
A. Boat was excessively healed over
B. Leaking gasket in sea strainer
C. Leaking gasket in raw water pump
D. Blockage in compressor discharge
Wooden boat In what type of boat should A/C condensate not be drained directly into the
bilge?
toxic gas created when freon is heated (phosgene) Why must an A/C system be evacuated (recovery) before brazing?
prevent oxides from forming on inside of copper tubing Why use nitrogen gas inside copper tubing when brazing?
flare fitting What is the most dependable mechanical connection for refrigerant piping?
blown compressor seal What might it mean if a technician observes oil at or around refrigerant fittings?
Exam Review UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
Absolute Humidity The weight of water vapor in a given amount of air (Grains per cubic foot)
Absolute Pressure Pressure measured with a base of zero
Absolute Temperature A temperature scale using absolute zero as a reference - Rankin or Kelvin Scale
(may be measures in degrees C or F)
Absolute Zero Theoretical temperature at which all molecular activity ceases = -273.16 C or
-456.69 F
250% By approximately how much (%) does a start capacitor increase motor torque?
C. Both Tech A says that it is possible to identify the start and run windings of a motor
with an ohm meter by noting which has higher resistance, indicating the start
windings. Tech B say the highest resistance will be noted when measuring from
run to start terminals. Which is correct?
A. Tech A
B. Tech B
C. Both
D. Neigher
Compressor The heart of a system, keeps the refridgerant flowing at specific rates of flow, at
specific temperatures.
Inlet (suction), shuts down system if pressure drops too On which side of a compressor is the low pressure switch, inlet or outlet, and
low. what function does it provide?
Outlet, shuts down compressor if pressure gets too On which side of a compressor is the high pressure switch, inlet or outlet, and
high (to protect the compressor). what function does it provide?
Condenser Air or water cooled heat exchanger which absorbs latent heat energy of hot
refridgerant gas and causes it to become a liquid.
Metering Device (AKA Expansion Device/Tube/Valve, Maintains a specific rate of flow from the high-pressure side of a refridgeration
TXV, or Capillary Tube) system into the low-pressure side.
Evaporator Air heat-exchanger that allows heat from incoming air to pass into the cold
refridgerant liquid which absorbs latent heat and evaporates in the process,
cooling the exit air.
KLIXON overload protector Trademark for a popular manufacturer of compressor overload protector
device. (Also manufactures overcurrent protection devices, switches, and
thermostats used in HVAC systems)
Running at lower than rated voltage (increases current What is a common cause of motor winding insulation leakage/breakdown?
draw and thus temperature of windings)
, 3.412 BTU's/Hour = 1 Watt 1 Watt is equal to how many BTU's per hour?
1 BTU / hr = 0.293 Watts 1 BTU per hour is equal to how many Watts?
Tech B (motors have PF < 1) When calculating power draw for a motor, Tech A says to multiply Amps by
Volts. Tech B says this is true, but it would be more accurate to include a third
multiplier, Power Factor to give accurate real power draw. Who is most correct?
Potential Relay Another name for Start Relay
return should be 20% bigger than source Ho much bigger should an air conditioning return duct be compared to the
discharge duct?
Waist heigh or higher At what height should A/C discharge ducts be located in the cabin?
low, near the floor At what height should A/C return duct sources be located in the cabin?
risk of CO ingress Why should A/C condensate drain hose not be discharged into the engine
room bilge area?
3 feet What is the minimal distance on the outside of the hull between A/C
condensate discharge outlet and engine exhaust outlet?
5/8 inch What is the minimum diameter recommended for A/C condensate drain hose?
increased suction causing low-pressure switch What are some possible manifestation from an overly dirty A/C air filter?
activation or tripped circuit breaker
True T or F: although ABYC does not require double hose clamping on thru-hull
seacocks, ISO standards and many manufacturer's do recommend it.
48 inches What is the max distance between support clamps for refrigerant piping?
B. Leaking gasket in sea strainer A technician notices air bubbles visible through the clear section of a raw-water
sea strainer. What is the most likely cause?
A. Boat was excessively healed over
B. Leaking gasket in sea strainer
C. Leaking gasket in raw water pump
D. Blockage in compressor discharge
Wooden boat In what type of boat should A/C condensate not be drained directly into the
bilge?
toxic gas created when freon is heated (phosgene) Why must an A/C system be evacuated (recovery) before brazing?
prevent oxides from forming on inside of copper tubing Why use nitrogen gas inside copper tubing when brazing?
flare fitting What is the most dependable mechanical connection for refrigerant piping?
blown compressor seal What might it mean if a technician observes oil at or around refrigerant fittings?
