NATE Air Conditioning and Heat Pumps Practice Exam

What problem results when the limit temperature of the discharge line at the compressor is exceeded?

1. Evaporator superheat will be excessive, causing capacity loss

2. Gassing of the indoor metering device will occur during the cooling cycle

3. Subcooling in the condenser will decline to a dangerously low level

4. Temperature in the compressor will be high enough to vaporize the lubricant

The correct answer is: Temperature in the compressor will be high enough to vaporize the lubricant

When the limit temperature of the discharge line at the compressor is exceeded, it results in a situation where the temperature within the compressor rises significantly. This excessive heat can cause the lubricant used to cool and protect the compressor components to reach its vaporization point. If the lubricant vaporizes, it can no longer effectively lubricate the moving parts of the compressor, leading to increased wear and tear, overheating, potential mechanical failure, or even complete breakdown of the compressor. Maintaining an appropriate discharge temperature is crucial for ensuring that the system operates efficiently and that the compressor remains properly lubricated. When the discharge line temperature is too high, the risk of lubricant vaporization increases, which can seriously compromise the longevity and functionality of the entire system.