UNIT 32 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX
32-1) What attraction and repulsion behavior do the north and south poles of a magnet
exhibit?
32-2) Explain the left hand rule for flux direction in conductors.
The left hand rule is used to determine the direction of rotation of the flux around
32-3) What is the most common source of power for most HVACR systems?
32-4) What is the purpose of transformers?
32-5) What is a solenoid valve?
32-6) Is there an electrical connection between the primary and the secondary
windings of a transformer?
32-7) What could be the cause of a loud hum coming from a transformer?
32-8) How are capacitors broadly categorized?
32-9) Describe how a DC capacitor would differ from an AC capacitor.
DC capacitors have positive + and negative – terminals and must be
32-10) What is capacitive reactance?
32-11) What are the two types of transformers?
32-12) Explain where single-phase power and three-phase power are normally used.
32-13) The phase shift factors which affect the power calculation E × I relate to
what circuits?
32-14) What is the impedance of a single-phase inductive circuit having a voltage
of 120 V and a current flow of 5 A?
32-15) What are the four common low voltage systems available to consumers?
32-16) Why is three-phase power most often used by large HVACR
equipment operators?
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32-17) Why is single-phase power used for most HVACR residential and
light commercial systems?
32-18) What can happen if electrical power wiring is not sized properly?
32-19) Find the minimum circuit ampacity (MCA) for a roof top unit that has the
following data listed on its nameplate: compressor FLA 26, two Fans FLA 3.0
each.MIC = (1.25 × 26) + 3.0 + 3.0 = 38.5 amps
32-20) What can happen if an oversized fuse or circuit breaker is installed and the
circuit is allowed to pass too much current?