Solution to the Malfunction of Cylindrical Initial Cleaning Screen

Grain stops cost money per minute. With this solution, you can turn downtime into a ten-minute routine check.

Motor Won’t Start

Check Power First

Use a multimeter to test three-phase voltage; if the difference exceeds 10 V, stabilize it. After resetting the emergency stop, a silent motor usually means a blown fuse—replace it with the same rating. If the contactor’s contacts are blackened, sand them with 1000-grit paper to restore conductivity. Check cable joints for oxidation; apply conductive paste if needed.

Reset Thermal Relay

After an overload trip, let the motor cool for five minutes, then press the blue reset. If it trips twice, reduce feed or add lubricant. Log the trip current; if it is 15 % above rated, lower the load or inspect the motor.

Screening Drops Sharply

Clean the Screen

Power down, remove the end cover, and sweep the mesh with a nylon brush. Stubborn residues yield to 0.4 MPa compressed air. Replace any screen with a tear larger than 2 cm to prevent edge rips. After cleaning, press the mesh—3 mm rebound is ideal.

Fine-Tune Speed

On the VFD, adjust in 2 Hz steps. For wheat, 45 r/min works best; for corn, 50 r/min. Stop when impurities fall below 0.5 %. Label the setting for next time.

Vibration or Noise

Tighten Feet

Torque anchor bolts to 180 N·m in a diagonal pattern. Re-level with a spirit level—error must be ≤0.2 mm/m. If vibration persists, remove hard debris and re-balance.

Grease Bearings

Every 200 hours, inject lithium grease until the cavity is half full. If temperature exceeds 70 °C, stop and check for lack of oil or damage. Use a puller to replace bearings, then run at low speed for ten minutes to break them in.

Belt Slips or Breaks

Adjust Tension

Loosen motor slide screws until the belt deflects 10 mm at mid-span, then lock. Recheck after 24 hours; add a 1 mm shim if it loosens.

Replace in Pairs

Swap both belts if cracks exceed 1 mm or wear tops 20 %. After fitting, run empty for five minutes; adjust motor level if the belt drifts off-center.