IR, PI and Absorption test
The IR / PI test is an excellent means of finding windings for contamination and moisture presence in stator and rotor windings. The test is also good for detecting major flaws where the insulation is cracked. In form wound stators with thermoplastic insulation systems, the test can also detect thermal deterioration. The test is performed by applying megger voltage and finding Insulation Resistance, Polarisation Index and Absorption ratios & graphs.
Winding Resistance Measurement
The stator DC winding resistance is measured to check for electrical unbalance due to shorted turns or open circuit faults in the winding. Low resistance Micro-ohmmeter is used for winding resistance measurement.