In the “real world” how often is it practical to replace the oil in a vacuum pump?
a. After every 5 evacuations or after each evacuation of highly contaminated systems.
b. When the oil turns white from moisture or dark amber from removing acid.
c. Vacuum pumps must always have their oil changed after each use.
a. After every 5 evacuations or after each evacuation of highly contaminated systems.
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Two-pole starters are used for ____.
a. single-phase motors b. three-phase motors c. compound motors d. three-wire AC systems
Some multisplit systems operate all indoor units from one control while others allow individual indoor units to operate from their own controls and set points
Indicate whether the statement is true or false
In the diaphragm-spring clutch, forward movement of the throw-out bearing causes the diaphragm spring to _____.
A. straighten B. expand C. contract D. engage the disc
All of the following statements about the recirculating ball steering gears are true EXCEPT:
A. Can be manual-type with no hydraulic assist B. Are used with parallelogram steering linkage C. Can be power-type with hydraulic assist from the power steering pump D. The lower end of the sector shaft is splined to the tie-rod end