Horizontal Screen Troubleshooting: Diagnose & Fix Any Problem

Problem 1: Screen Won't Start

Symptoms & Causes

Symptoms: Motor hums but no movement, breaker trips immediately.

• Electrical fault or dropped phase (30%)
• Seized bearing in the vibrator unit (25%)
• Belt failure or extreme looseness (20%)
• Overload protection active (15%)
• Mechanical obstruction in the chassis (10%)

Step-by-Step Fix

1. Check electrical supply (voltage and phases) at the panel.
2. Inspect drive belts for damage or slippage.
3. Manually rotate the drive shaft to check for severe binding.
4. Reset overload protection relays.
5. Test motor independently decoupled from the screen.
6. Call a technician if a seized bearing is confirmed.

Problem 2: Uneven Material Distribution

Symptoms & Causes

Symptoms: Material piles heavily on one side of the deck.

• Feeder misalignment or uneven chute discharge (40%)
• Uneven deck level / poor foundation settlement (30%)
• Worn, broken, or mismatched suspension springs (20%)
• Damaged or packed side liners creating drag (10%)

Step-by-Step Fix

1. Check feeder centering and adjust the deflector plates in the feed box.
2. Level the screen deck transversely using a spirit level on the stationary frame.
3. Inspect all springs for wear, measure compressed height, and ensure they are a matched set.
4. Clean out packed material and replace damaged side liners.

Problem 3: Excessive Vibration or Noise

Symptoms & Causes

Symptoms: Deafening metallic noise, visible wild shaking, or bouncing.

• Unbalanced exciter weights between left and right sides (35%)
• Loose structural bolts across the side plates (25%)
• Severely worn or failing bearings (20%)
• Broken suspension springs causing bottoming out (15%)
• Resonance with the support structure (5%)

Step-by-Step Fix

1. Immediately tighten all structural Huck bolts or high-tensile fasteners to spec.
2. Check exciter counterweights to ensure absolute symmetry.
3. Measure bearing temperature; if >90°C, a bearing is failing.
4. Inspect springs for cracks and ensure the screen isn't hitting bump stops.
5. Stiffen the support structure if it's swaying sympathetically.

Problem 4: Poor Screening Efficiency

Symptoms & Causes

Symptoms: High percentage of oversize particles in the undersize stream, or vice versa.

• Blinded screen mesh from moisture/clay (30%)
• Excessive feed rate burying the apertures (25%)
• Wrong ellipse angle for the material type (20%)
• Severely worn screen media holes (15%)
• Low amplitude due to slipping belts (10%)

Step-by-Step Fix

1. Clean or replace the screen media; add anti-blinding balls if necessary.
2. Reduce the feed rate by 20% to observe if efficiency returns.
3. Adjust the ellipse angle (closer to 45° for sticky, 25° for dry/fast passing).
4. Check drive belt tension to restore full amplitude.

Problem 5: Bearing Overheating

Symptoms & Causes

Symptoms: Bearing housing temperature >90°C, smoking grease.

• Insufficient lubrication or wrong grease type (40%)
• Contaminated grease from dust ingress (25%)
• Shaft misalignment or bent shaft (20%)
• Overloading the machine beyond capacity (10%)
• End of physical bearing life (5%)

Step-by-Step Fix

1. Confirm you are using correct high-temperature, EP vibrating screen grease.
2. Purge the old grease completely while running, until clean grease appears.
3. Verify shaft alignment across the mechanism.
4. If symptoms persist after purging, plan an immediate bearing replacement to prevent catastrophic shaft damage.

When to Call a Technician

Stop the machine and call for service if you experience:

• Bearing replacement needed.
• Structural cracks detected on side plates or crossbeams.
• Complete electrical motor failure.
• Shaft alignment or damaged gears in a triple-shaft unit.