Circuit Breaker Repair Procedures by Type

Molded Case Circuit Breakers (MCCB)

Step 1:Perform visual inspection for signs of damage, burning, or wear

Step 2:Test the mechanical operation and verify smooth toggle movement

Step 3:Clean all surfaces using approved electrical contact cleaner

Step 4:Check and tighten all terminal connections to proper torque specifications

Step 5:Test trip mechanisms and calibrate if necessary

Step 6:Perform insulation resistance testing

Note:If internal components are damaged, replacement is typically recommended over repair due to the sealed nature of MCCBs.

Low Voltage Power Circuit Breakers

Step 1:Remove breaker from cubicle and place on maintenance cart

Step 2:Disassemble outer housing and inspect all components

Step 3:Clean all parts, including contacts, arc chutes, and mechanisms

Step 4:Replace worn contacts and springs as needed

Step 5:Lubricate all moving parts with appropriate lubricant

Step 6:Check and adjust contact alignment and pressure

Step 7:Test operating mechanism and adjust trip settings

Step 8:Perform electrical testing including contact resistance

Step 9:Reassemble and perform final operational checks

Medium Voltage Circuit Breakers

Step 1:Rack out breaker and transfer to maintenance area

Step 2:Perform SF6 gas testing (if applicable)

Step 3:Open breaker housing and inspect vacuum bottles or SF6 interrupters

Step 4:Clean all insulating components and check for tracking

Step 5:Inspect and service operating mechanism

Step 6:Replace worn components including contacts and springs

Step 7:Check and adjust trip linkages

Step 8:Perform timing tests and mechanical operations

Step 9:Conduct high-potential testing

Step 10:Verify all safety interlocks are functioning

High Voltage Circuit Breakers

Step 1:Isolate breaker and ground all terminals

Step 2:Test and reclaim SF6 gas (if applicable)

Step 3:Disassemble breaker components

Step 4:Inspect and test interrupter assemblies

Step 5:Service operating mechanism (hydraulic or spring)

Step 6:Replace seals, gaskets, and worn components

Step 7:Check and service control cabinet components

Step 8:Perform timing and travel analysis

Step 9:Refill SF6 gas to proper pressure (if applicable)

Step 10:Conduct operational and electrical testing

Important Safety Notice:Circuit breaker repair should only be performed by qualified electrical technicians with proper training and equipment. All safety procedures and manufacturer guidelines must be followed.

Preventive Maintenance Tip:Regular inspection and maintenance can prevent many common circuit breaker failures and extend equipment life. We recommend establishing a routine maintenance schedule based on manufacturer recommendations and operating conditions.