单选

In a refrigeration system, which of the following statements describes the actions occurring when a solenoid valves, used in conjunction with an unloader head is energized? .

  • A.The solenoid valves directs high pressure gas to the valve lifting device raising the suction valve off its seat and causing one specific cylinder to become unloaded
  • B.The solenoid valves directs high pressure gas to the underside of the unloading piston, causing it to rise and allowing the recirculating ports to be opened
  • C.When the solenoid valve becomes energized, the valve ports become closed, allowing discharge pressure to build up above the piston, shifting it and causing it to unload
  • D.The solenoid valve allows the refrigerant to pass from the suction chamber to the top of the unloader piston, causing the piston to lift and unload the cylinder
参考答案
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