Pneumatic

We investigated an instrument-air compressor and dryer system where the compressor, dryer regeneration, drain valves, and pressure control were not operating as expected. Initial symptoms included: Dryer not regenerating properly Water accumulating in the air system Drain valves not operating correctly Instrument-air leakage Compressor pressure cycling abnormally Initial hypotheses included: Faulty solenoid valves Actuator problem Instrument-air leakage Pressure switch problem Electrical cable fault Incorrect sequence timing During investigation, several individual faults were found. ...

During troubleshooting of a pneumatic dryer system, several solenoid valves were investigated because the expected valve operation was not occurring. The first electrical check was coil resistance. Most coils showed approximately 300 ohms, which initially indicated that the coils were electrically intact. However, resistance measurement alone could not confirm that the complete solenoid valve was functioning correctly. The valve inputs and outputs were then checked by applying the control voltage and observing the actual valve state. ...