What must a driver monitor when the Compressor Fault illuminates on a 3 car train?

When a Compressor Fault is indicated on a 3-car train, it is crucial for the driver to monitor the Main Reservoir (MR) pressure. The MR pressure is vital as it supplies the necessary air to various systems, including the braking and suspension systems of the train. A fault in the compressor can lead to insufficient air pressure, which may affect the train's ability to operate safely and effectively.

Maintaining an adequate MR pressure is essential for ensuring that air-operated systems function correctly; a drop in this pressure could compromise operational safety by impacting the braking performance or causing instability in the train. Therefore, continuous monitoring of MR pressure after a Compressor Fault alert is essential for prompt corrective action, ensuring the train operates within safe standards.

Monitoring other factors like train air pressure, train stability, and pantograph operation may be relevant in different contexts or faults, but in the case of a Compressor Fault, MR pressure is the priority for addressing the potential immediate safety concern.