A logistics warehouse reported that a Toyota 8FBE15 electric forklift emitted a burning smell and visible sparks from the traction motor cover after 1 hour of continuous operation. The machine would then cut power (thermal protection trip).
The technician removed the "Traction Motor Inspection Cover." The brushes were worn down to less than 10mm (limit is 15mm). The "Brush Springs" were weak, causing the brushes to bounce. The bouncing created "Electrical Arcing" (sparks), which generated high heat. The burning smell was ozone and burning dust.
He also checked the "Motor Ventilation Duct." The duct was completely blocked with packaging dust and paper scraps. The traction motor is cooled by a fan on the shaft. The blocked duct prevented airflow, causing the motor temperature to rise rapidly. The combination of arcing heat and lack of cooling triggered the thermal switch.
The repair involved replacing all four carbon brush sets and the brush springs. The motor commutator (copper segments) was cleaned with a "Commutator Stone" to remove the carbon buildup and pits from the arcing. The ventilation duct was cleaned with compressed air. The technician advised the warehouse manager to schedule weekly cleaning of the motor ventilation intakes to prevent recurrence. The forklift then ran for a full shift without tripping.
