Question 40Refrigeration/AC - Assistant Engineer70% to pass
On a modern refrigerated container unit employing suction modulation for the purposes of capacity control and capacity limitation, what happens when the applied voltage and current draw associated with the normally open (NO) suction modulation valve located in the suction line both increase?
AI Explanation
The correct answer is B) the valve will further close, raising evaporator pressure and lowering suction pressure.
In a refrigerated container unit with a suction modulation valve, an increase in the applied voltage and current draw to the normally open (NO) valve will cause the valve to further close. This closing action will restrict the flow of refrigerant through the suction line, leading to a rise in the evaporator pressure and a corresponding decrease in the suction pressure.
The other options are incorrect because: A) would result in a decrease in evaporator pressure and an increase in suction pressure, which is the opposite of what occurs; C) and D) describe the opposite valve action (further opening) when the applied voltage and current draw increase, which is not accurate for a normally open suction modulation valve.
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