As shown in the illustrated refrigeration system piping schematic diagram with the various accessories and controls and equipped with an air-cooled condenser with high side pressure controls, what statement is true concerning the fan cycling control pressure switch? Illustration RA-0039
• High-side (condensing) pressure control in an air‑cooled condenser • Effect of ambient air temperature on condenser pressure and required airflow • How a fan cycling pressure switch maintains minimum head pressure by starting/stopping or speeding/slowing condenser fans
• When outside air temperature drops, what happens to condensing pressure if the condenser fan keeps moving maximum air? Does pressure go up or down? • Under which ambient condition do you need more condenser airflow, and under which do you need less, to keep head pressure in the proper range? • Look at the diagram: the fan‑cycling control is sensing high‑side pressure. If that sensed pressure falls below the setpoint, should it increase or reduce fan operation?
• Be sure you understand that the control switch is responding to high‑side pressure, not temperature directly. • Match each answer choice to whether fan operation would cause the head pressure to rise or fall under the stated ambient condition. • Eliminate any option where fan action would push the head pressure further away from the desired operating range instead of keeping it within limits.
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