A Marine Client runs two vessels travelling between Australia and New Zealand that transports cargo and cattle. The crossing runs six days a week conducting regular condition monitoring tests to help avoid very costly service outage.
The motor requiring testing was a bow thruster, which assists with maneuvering the ship during docking. If the motor is out of service the vessel has to hire a tug each time they come into port and leave at a cost of up to $20K per request.
The size of the motor tested:
- Large 425 kW (duty cycle S2, 30mins), 3 phase induction motor
- 1487 RPM
During periodic routine motor testing the initial test results showed the motor passed all tests, but on closer inspection, the high voltage Pulse to Pulse EAR was showing insulation breakdown and instability.
The vessel had a scheduled dry dock and the motor was removed for service. When the motor was dismantled a section of the winding was showing signs of insulation degradation. The motor was repaired within the scheduled dry dock period and the vessel is currently in service.
The customer was very satisified with the service saying “if this fault was not detected and the motor had failed during its normal service period it’s estimated that the additional costs would have been in the vicinity of $240K”. (This does not include likely consequential and mobilisation costs usually associated with unscheduled breakdown outages and urgent repair costs).
AVO NZ are the New Zealand agency for Megger Baker Instruments. AVO NZ work closely with TRS, providing our team with valuable training. Find out more about how TRS can provide motor testing for your rotating machinery using the Megger Baker equipment here.
Case Study supplied by Megger Baker Instruments.