During maneuvering on a slow speed diesel engine vessel, a low starting air system pressure alarm is activated. Local starting air receivers' pressure gauges indicate proper pressures, and compressors are running and are 'loaded' up. What could cause the alarm?

Correct Answer: Option D — Faulty system alarm pressure switch and/or a fault in the alarm circuit.

When local receiver gauges and compressor performance confirm normal system pressures, an activated low starting air pressure alarm indicates instrumentation failure. The root cause is a faulty system pressure switch or an electrical fault within the alarm monitoring circuit.