Accelerated ageing experiment for induction motor insulation due to humidity effect

In this paper, accelerated aging process on induction motor insulation caused by high humidity environtment is investigated. Induction motor is operated inside experiment chamber with high humidity to accelerate the insulation deterioraton. Insulation resistance (IR) and polarization index (PI) values are used to evaluate insulation condition. Moreover Scanning Electron Microscopy-Energy Dispersive X-ray analyzer (SEM-EDAX) test is performed to understand the microscopic insulation surface condition. The result shows that the moisture caused by high humidity environtment is decreasing PI index significantly eventhough the IR is high. In the certain condition, white powder is visible on end winding of motor. Based on SEM-EDAX analysis, this powder is mineral sedimentation that attached on insulation surface.