Symptoms of non condensables (Air/Nitrogen) in system

High head pressures

High Pressure trips

High compressor head temperature

High Discharge temperature

May also cause sudden drops in the temperature in the condenser

Air also contains impurities such as moisture which may cause the system to
block or the oil and refrigerant to react and form acid which will breakdown the
motor windings

Run time of the compressor may be increased and excessive current drawn

The system may show moisture on the site glass indicator