Air Circuit Breakers

Steps for Servicing an Air Circuit Breaker

1. Inspection

   • Check for broken, damaged, significantly aged, or missing parts.
   • Look for signs of excessive wear, temperature issues, and corrosion.
   • Repair or replace any faulty components immediately.

2. Main Contacts Examination

   • Clean main contacts using silver cleaner or alcohol with non-abrasive cloths.
   • Inspect for wear, especially after exposure to short-circuit currents.
   • Ensure contacts are properly aligned and spring pressures meet manufacturer specifications.

3. Arc Chutes Inspection

   • Clean and check for dirt, moisture, and damages.
   • Avoid using wire brushes or emery cloth; use light sanding and a vacuum for dust removal.
   • Ensure arc chutes are functioning properly to clear short circuits.

4. Operating Mechanism Check

   • Ensure device and chassis mechanisms are clean.
   • Secure all screws and bolts properly.
   • Verify lubrication levels are as per manufacturer’s specifications.

5. Air System Checks

   • Inspect for air leakages and plug any found immediately.
   • Check for oil leakages in grading capacitors monthly.
   • Measure dew point of operating air at the air dryer’s outlet to ensure it falls within necessary limits.

6. Electrical and Functional Tests

   • Conduct tests for flawless operation of mechanisms.
   • Perform insulation resistance tests.
   • Test for instant tripping and overcurrent.

7. Reassembly and Reporting

   • Reassemble the circuit breaker to its original state.
   • Create a report on the maintenance process for safety inspectors.