Earth fault detected in electric propulsion motor

Using patented SPM HD shock pulse technology, the online condition monitoring system Intellinova Compact detected a motor fault in an electric propulsion system on board a construction support vessel. The case illustrates how condition monitoring solutions for marine and offshore support early fault detection and planned maintenance.

Application and monitoring setup

A diesel-electric propulsion motor was monitored using an Intellinova Compact online system with two shock pulse transducers installed at the drive end and non-drive end of the motor. An RPM sensor measured rotational speed from the shaft between the electric motor and the gearbox.

Results and benefits

When the fault occurred, a sudden increase in the symptom trend and a moderate increase in the SPM HD trend were observed. Applying the Decision Support System showed that the increase was present in both trends.

In this case, a short-circuit between one of the phases and earth caused an earth fault. Condition monitoring enabled early detection of the electrical problem, allowing motor replacement to be planned and scheduled at a suitable time.