Why could a recycling or recovery machine that uses a hermetic compressor overheat when drawing deep vacuums? (A) A) It has a higher compression ratio limit than other equipment. (B) B) The oils used in hermetic compressors are a lower viscosity than the oils used in other equipment. (C) C) The motor relies on the flow of refrigerant through the compressor for cooling. (D) D) It runs faster than other equipment with oil less compressors.

To determine why a recycling or recovery machine that uses a hermetic compressor might overheat when drawing deep vacuums, let's analyze each option: (A) **It has a higher compression ratio limit than other equipment.** - This statement is not directly related to overheating. A higher compression ratio could lead to increased temperatures, but it does not specifically explain overheating during deep vacuum operation. (B) **The oils used in hermetic compressors are a lower viscosity than the oils used in other equipment.** - While oil viscosity can affect lubrication and heat transfer, this option does not directly address the issue of overheating during deep vacuum operation. (C) **The motor relies on the flow of refrigerant through the compressor for cooling.** - This is a critical point. In hermetic compressors, the refrigerant flow is essential for cooling the motor. When drawing deep vacuums, the refrigerant flow may be reduced, leading to insufficient cooling and potential overheating of the motor. (D) **It runs faster than other equipment with oil-less compressors.** - The speed of the compressor may contribute to overheating, but it does not specifically relate to the issue of drawing deep vacuums. Based on this analysis, the most accurate answer is: **(C) The motor relies on the flow of refrigerant through the compressor for cooling.** This explains why the hermetic compressor could overheat when drawing deep vacuums, as reduced refrigerant flow can lead to inadequate cooling.