The oil in a vacuum pump should be changed _____
a. about every five minutes of pump operation
b. only when changing from one refrigerant to another
c. immediately after pumping down a wet or contaminated system
d. about every 25 hours of pump operation
c
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The free market would:
a. Stabilize prices. b. Provide a cushion under land prices. c. Decrease U.S. competitiveness in world markets relative to current programs. d. Require farmers to develop financial management and marketing strategies to survive. e. c and d above.
The phase current of a wye-wound three-phase motor is:
A) 1.73 times the line current. B) Equal to the line current. C) 1.5 times the line current. D) 3 times the line current.
Which of these is a California standard even tighter than ULEV, including much lower HC and NOx emissions; roughly equivalent to Tier 2 Bin 2 vehicles?
A) ULEV (also known as ULEV I)—Ultra-Low-Emission Vehicle B) ULEV II—Ultra-Low-Emission Vehicle C) SULEV—Super-Ultra-Low-Emission Vehicle D) ZEV—Zero-Emission Vehicle
If a 250,000 circular mil cable is composed of 37 strands, what is the approximate diameter of each strand? Carry the answer to two decimal places.
Fill in the blank(s) with the appropriate word(s).