What is the recommended oil level in the sight glass of a running semi-hermetic compressor?

For a running semi-hermetic compressor, the recommended oil level in the sight glass is typically ½ full. This level indicates that there is enough oil present to adequately lubricate the compressor's moving parts while also ensuring that the oil return system functions properly. Maintaining the oil level at this point allows for optimal performance, reducing the risk of overheating and wear on the compressor.

An oil level that is too low can lead to insufficient lubrication, resulting in increased friction and potential damage to the compressor. Conversely, an oil level that is completely full can cause aeration of the oil, leading to less effective lubrication and possibly impacting compressor efficiency. Therefore, keeping the oil level at around ½ full strikes a balance that supports the compressor's operational integrity.