Standard Remanufacturing Procedures for 5 KV – 38 KV
Air Circuit Breakers

1. Unpack air circuit breaker(s)

1. Inspect overall condition for any shipping damage
2. Record all nameplate data

2. Preliminary Evaluation

1. Remove complete dustcover
2. Inspect overall condition
3. Inspect contacts, arc chutes and complete operating mechanism
4. Check control wiring, develop schematic and point to point wiring diagram(s)
5. Operate circuit breaker, slow close, manual operation and electrical operation.
6. Apply 100 amp digital low resistance ohmmeter to each phase (Record readings)
7. Apply DC hi-potential test to each phase and phase to ground. (Record readings)

3. Remove all three (3) arc chutes from circuit breaker

4. Disassemble arc chutes completely to each elemental part

1. Remove stack assembly
2. Remove blowout magnet pole faces
3. Remove screws from arc chute enclosure
4. Separate arc chute halves
5. Lift out blowout magnet core
6. Remove gas baffles
7. Lift out transfer plates and interrupter plate assemblies.
8. Remove blowout coils and insulation

5. Remove pole units, completely disassemble to each elemental part.

1. Document all phase to phase measurements
2. Document all base plates shims required
3. Remove disconnecting contact finger clusters and disassemble to each elemental part
4. Remove main contact hinge pin and hinge spring washers, movable and stationary contact.
5. Remove bolts from moveable main contact blades and disassemble to each elemental part.
6. Remove main contact stationary mounting bolts and fingers, disassemble to each elemental part.
7. Remove arcing contact mounting bolts and disassemble to each elemental part
8. Remove arc chute hinge bracket bolts and disassemble to each elemental part.

6. Remove all control wiring and associated components, close coil trip coil, auxiliary switch, control relay, and secondary coupling

7. Dismantle mechanism to each elemental part

1. Remove complete puffer assembly
2. Remove both side plates
3. Remove close springs/crossbar
4. Remove front and rear plates
5. Disassemble mechanism to each elemental part
6. Remove latching assembly and plunger

8. Inspect all bearings, spring tensions and puffer rings for wear (replace each part as required)

9. All current carrying components cleaned and silver electro-plated to a tolerance of 0.0015 thickness and treated with tarnaban to prevent oxidation.

10. All metal plated components cleaned, stripped and re-zinc plated per Federal Spec. QQ-Z-325A/QQ-Z-325B Type 2 Class 3

11. All painted parts to be completely stripped, primed, and re-painted to original colors

12. Engineering Re-evaluation

1. Inspect and evaluate each elemental part
2. Advise mechanic what parts must be replaced
3. Dress or replace main and arcing contacts as required

13. Re-assembly by air circuit breaker technician

       A. Mechanism re-assembly (Note: Original Equipment Manufacturer                                           
                  Recommended lubricant to be used on all mechanism parts)

1. Re-assemble latching assembly
2. Install plunger and latch assembly
3. Re-assemble inner operating mechanism components
4. Adjust all gaps and wipes per original manufacturer’s specifications
5. Install mechanism in frame
6. Re-assemble inner mechanism to sides, front and rear frame assemblies
7. Install closing and opening springs
8. Install puffer assemblies (Check for alignment and verify sufficient seal is made between puffer rings and housing as per manufacturer’s specifications)
9. Install electrical components, rewire using Type SIS OSHA approved wire.

14. Re-assemble pole units to original manufacturer’s specifications

(Clean, re-coat or replace each part as required, Note: Original Equipment Manufacturer lubricant to be used on hinge joint, primary and secondary disconnect and auxiliary switch)

1. Mount pole units on mechanism base by replacing shims as previously recorded
2. Align pole units to OEM Specifications
3. Adjust puffers and main contact assemblies as per Manufacturer’s specifications.

15.      A. Re-assemble contacts (Clean, re-silver, re-plate or replace each part as
                        Required)

Stationary
Dress or replace main contacts and re-install in retainer using new contact springs

Dress or replace arcing tips and re-install into retainer
Install flex braid onto retainer

Moving
Dress or replace main contacts
Dress or replace arcing tips
Re-assemble into casting using contact braid and pin

1. Re-assemble bushings assemblies (Clean, re-coat or replace each part as required)

1. Replace or re-coat sleevings if required
2. Install six (6) bushings using four (4) bolts, flats, locks and nuts
3. Install main contacts, arcing tips and hinge arms
4. Set all poles back to original manufacturer’s tolerances
5. Install operating push rods
6. Set all contact adjustments to manufacturer’s specifications
7. Check for loose hardware, re-check the bushing centers
8. Install magnet assembly using re-coated or replaced support fibers

1. Reassemble arc chutes (Clean, re-coat, re-silver, replate or replace each part as required)

1. Place arc chute housing on its front and insert bottom arc runner spaces and shims
2. Install stack assembly and upper arc runner
3. Place top fiber on top of arc runner and spacers
4. Insert screws (4 on each side)
5. Note: Stack assemble and all internal parts must be cleaned and tightened
6. Install arc chutes on breaker, check that they slide easily on magnet assembly
7. re-assemble and install dust cover

            16. Re-assemble arc chutes (Clean, re-coat, or replace each part as required)

1. Prior to arc chute enclosure assembly, engineer to inspect hardware tightness

17. Testing

            Mechanical Tests

1. Complete hardware check (Bolt Torque Test)
2. Complete manual charge, close and trip operations
3. Verify main contacts (Alignment and Compression)
4. Verify arcing tips (Alignment and Compression)
5. Hinge joint pressure
6. Confirm proper puffer operation
7. Verify proper racking mechanism and all cell interlock functions, install air circuit breaker in Original Equipment Manufacturers cubicle
8. Record all readings

Electrical Tests
A. Operate circuit breaker at control voltage and ranges (Set by original    
                       manufacturer)
      B. Continuity test of control wiring
      C. Test wiring as per schematic previously generated
      D. Perform DLRO Test (100 Amp)
      E. Record all readings

      Insulation Tests

1. Perform DC hipot for 1 minute (37.5 KV DC)
2. Record all readings

18. Optional tests available upon request

1. Speed and motion
2. Power factor
3. AC hipot
4. BIL Test