Usually come from a mix of design gaps, supplier quality issues, process variation, and poor handling. If you look closely at factories, most losses concentrate around a few critical areas—especially refrigeration, electrical assembly, and cabinet fabrication.
🔧 1. Refrigeration System Issues (High Impact Area)
This is one of the biggest contributors to NG and scrap.
Common causes:
- Refrigerant leakage due to poor brazing or welding
- Micro-leaks not detected during leak testing
- Compressor defects (supplier-related or damage during assembly)
- Improper vacuuming → moisture inside system → cooling failure
Result:
❌ No cooling / poor cooling → Full unit rejection (major NG)
⚡ 2. Electrical & Wiring Defects
Electrical issues are another top source of failures.
Common causes:
- Loose or incorrect wiring connections
- Wrong components (relay, thermostat, PCB)
- Poor insulation or exposed wires
- Control panel/display malfunction
Result:
❌ Safety risk + functional failure → NG or rework
🧊 3. Cooling Performance Failure
Even if the system works, performance may not meet spec.
Common causes:
- Incorrect refrigerant charge
- Poor airflow (fan issues or blocked vents)
- Insulation defects (PU foam gaps)
- Door gasket leakage
Result:
❌ Temperature not reaching 2–8°C → NG in final inspection
🏭 4. Sheet Metal & Cabinet Fabrication Defects
This affects both function and appearance.
Common causes:
- Incorrect bending or cutting dimensions
- Welding distortion
- Sharp edges or burrs
- Poor powder coating (peeling, bubbles, uneven finish)
Result:
❌ Cosmetic NG or assembly mismatch → scrap/rework
🚪 5. Door & Glass Assembly Problems
Very visible to customers—high rejection risk.
Common causes:
- Misalignment of doors
- Weak hinges or handle fitting
- Glass scratches or breakage
- Poor gasket sealing
Result:
❌ Air leakage + visual defects → NG
🧪 6. Insulation (PU Foam) Defects
Often hidden but critical.
Common causes:
- Incomplete foam filling
- Air gaps inside cabinet walls
- Wrong foam density
Result:
❌ Energy inefficiency + cooling loss → NG
🔊 7. Noise & Vibration Issues
Important for customer satisfaction.
Common causes:
- Improper compressor mounting
- Fan imbalance
- Loose internal components
Result:
❌ High noise level → customer complaints → rejection
📦 8. Packaging & Handling Damage
A major source of scrap after production.
Common causes:
- Weak packaging design
- No shock protection (foam/corner guards)
- Rough handling during transport
Result:
❌ Dents, glass breakage → scrap at warehouse/customer
👷 9. Human Error & Poor Workmanship
Very common in manual assembly lines.
Examples:
- Missing screws or components
- Incorrect assembly sequence
- Poor brazing quality
- Lack of standard work instructions
Result:
❌ Inconsistent quality → high NG rate
🏢 10. Supplier Quality Issues
If incoming parts are bad, final product will be bad.
Common problem parts:
- Compressors
- Thermostats / PCBs
- Fans
- Glass panels
Result:
❌ Line stoppage + bulk rejection