Mechanical Engineering Unit 80 Unit Review Questions Answer Keygo Back Index What The Function Low Temperature

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UNIT 80 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX

80-1) What is the function of a low temperature thermostat on a packaged air

handler?

80-2) What is the function of an air flow switch on a packaged air handler?

80-3) What input signal would control the speed of a variable frequency drive supply

fan?A static pressure sensor installed in the air flow.

80-4) What is the purpose of a high pressure switch in a packaged air handler?

80-5) What will an air quality sensor typically measure?

80-6) What is the purpose of a differential enthalpy sensor?

80-7) How does a refrigeration air dryer operate?

80-8) How would an electronic humidity control operate?

80-9) What is an important consideration to take into account when replacing

sensors?

80-10) Why are direct digital control systems (DDC) sometimes referred to as energy

management systems?

80-11) What could cause vibration in a large air handler fan?

80-12) What do vibration monitors specifically measure?

80-13) What types of control valves are used for heating and cooling coils?

80-14) What can happen if the pressure drop through a heating or cooling coil control

valve is excessive?

80-15) List some of the advantages of pneumatic control systems.

They provide an excellent means of modulating control operation.

80-16) What is background power?

80-17) What are some of the advantages of electronic control systems?

80-18) List some electronic temperature sensing elements.

Electronic temperature sensing elements are room thermostats, outdoor

80-19) What acts as the primary control for all HVACR functions in a DDC system?

80-20) What is a sensor?