We have one case where for Mill motors in Sugar industry, the bearings are repeatedly failing due to bearing current (Fluting Marks). The NDE side bearing is a insulated bearing though. After last failure incident we have changed the bearings (DE non insulated and NDE insulated). We have also installed Carbon/Grounding brush on DE shaft end out side the end cover. Also the earthing is checked. However again in this season only after operating for 4 months bearings have failed.
Can you guide me for identifying reason behind and with corrective actions.
Thanks and regards