The high-temperature limit switch mounted above or beside the heat exchanger of a gas furnace should
cycle open if _____.
a. a flame rollout occurs
b. the outdoor temperature exceeds 75°F
c. there is insufficient combustion air
d. the blower fails to operate
d
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The air in a classroom is maintained at 20ºC and 50% humidity in Colorado where the atmospheric pressure is 80 kPa. Using the equations, the humidity ratio is found to be nearest:
A) 0.0168 kgv /kga B) 0.0173 kgv /kga C) 0.0182 kgv /kga D) 0.0187 kgv /kga
Whenever possible, when changing a motor, the _________________________ should be obtained.
Fill in the blank(s) with the appropriate word(s).
____ are used to pressurize air to levels that are above atmospheric pressure.
A. Compressors B. Hydraulic systems C. Pneumatic systems D. Pumps
Which of the following statements is true regarding forecasting techniques?
A) Techniques that use external economic indicators are classified as extrinsic. B) Intrinsic techniques use historical data. C) Qualitative techniques are based on judgment. D) All of the above are true. E) None of the above is true.