Automotive Heating and Air Conditioning Exam

Pressures are controlled in an orifice tube (OT) system by - answer-Cycling an electromagnetic compressor clutch on and off as needed or Using a variable displacement compressor Which condition can cause the air-conditioning system to produce less-than normal cooling - answer-Either under-or overcharged The condenser - answer-Is a heat exchanger Is a device where air passing over it cools the refrigerant and causes it to change into a high-temperature liquid Transfers heat from the refrigerant to the air flowing In a piston-type compressor, the pistons are driven by a - answer-All of the above depending on the compressor Most piston compressors use what type of valves - answer-Reed The basic designs of A/C compressors include - answer-Piston, vane, and scroll Two technicians are discussing variable displacement piston compressors. Technician A says that the wobble plate is moved to the high-angle position for maximum output when the cooling load is high. Technician B says that the wobble-plate angle is controlled by the pressure in the crankcase of the compressor. Which technician is correct - answer-Neither A nor B Wobble-plate compressors commonly use how many cylinders - answer-Five or seven How is the A/C compressor lubricated in an R-134a system - answer-The oil moves through the system simply with the movement of the refrigerant Switches located on the compressor itself may include - answer-Any or all of the above A compressor speed (belt lock) sensor is used by the HVAC ECM to - answer-Prevent a locked-up compressor from destroying the engine drive belt Determine if the compressor is running, and by comparing the compressor and engine speed signals