When should an oil sample be taken from a low pressure system?

Taking an oil sample from a low pressure system is particularly important after recycled refrigerant has been added. This is because the introduction of recycled refrigerant can potentially alter the composition of the oil within the system. Contaminants or impurities can be present in recycled refrigerant, which might affect the system’s operation and efficiency. By sampling the oil at this stage, technicians can analyze it for contaminants or changes in chemical properties, ensuring that any necessary maintenance or corrective actions can be taken to protect the system's integrity and functionality.

While there are other situations that may warrant oil sampling, such as during maintenance or when leaks are detected, the timing after refrigerant recycling is critical for assessing the immediate impact this action can have on system performance. This proactive measure helps in preventing potential issues from developing due to contamination.