Fault Phenomenon: BelAZ 75306 electric wheel mining truck traction motor sparks heavily, power fluctuates.

Troubleshooting Process:
– Checked brush holder: carbon brush holder deformed due to overheating or mechanical impact.
– Checked carbon brushes: brushes stuck in holder, unable to spring out.
– Checked commutator: commutator surface burnt.
– Checked insulation: brush holder insulation to ground degraded.

Root Cause: The traction motor carbon brush holder thermally deformed due to long-term high-temperature operation, causing uneven contact pressure between brushes and commutator and generating strong sparks.

Required Parts: Straighten or replace carbon brush holder, replace carbon brushes.