UNIT 92 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX
92-1) List some common questions customers ask service technicians.
92-2) Explain what is meant by a systems approach to troubleshooting.
Technicians are called to work on the entire system, not an isolated part of it.
92-3) Give an example of an airflow problem that can look like a refrigerant charge
problem if a service technician is only looking at system pressures?
92-4) List the stages of troubleshooting.
Understanding System Operational Sequence
92-5) What checks are typically performed during the preliminary inspection?
Check the thermostat setting
92-6) What should a service technician do if they find a blown fuse in the unit
disconnect switch during the preliminary inspection?
92-7) What should a service technician do if they find a blown fuse in series with the
low voltage side of the transformer?
92-8) Outline a method of isolating an electrical fault using the process of
elimination.
92-9) Describe the process of hop scotching.
92-10) Using the logic flowchart in Figure 92-18, what is the first condition listed to
check for a compressor that will not run when the contactor is closed?
92-11) Using the troubleshooting systems list in Figure 92-19, what possible causes
are listed for a unit which experiences high pressure switch tripping only during
the cooling cycle?
92-12) Using the chart in Figure 92-20, what conditions cause both lights to display
an alternating fast flash?
92-13) Using the air source heat pump sequence chart in Figure 92-2, list the devices
in order that control the outdoor fan.
R control power to thermostat
92-14) Using the chart in Figure 92-17, what problems can cause both a high
superheat and a high subcooling?
92-15) Using the induced draft sequence chart in Figure 92-4, what should be
checked if the induced draft fan comes on but the igniter is never energized?
92-16) List some resources the air conditioning technician can use to learn about the
92-17) List some sources the air conditioning technician can use to get system
92-18) Using Figure 92-7, what should the approximate suction pressure be for an
EC015 system operating in heating with an entering water temperature of 50°F
and a water flow of 2.8 GPM?
92-19) Why are diagnostic codes not always able to identify the system problem?
92-20) Why should service technicians be familiar with company pricing policies?