Overhauling & testing of Circuit breakers

Checklist for Vaccum Circuit Breakers

Operation of the Mechanism both Electrically and Manually.
Verification of Required Alignments.
Verification of Tripping and Closing Operations.
Inspection and Testing of Tightness for All Control Cables and Isolating Contact Tightness.
Checking Of All Insulation Resistance. (Closed and opened condition)
Checking, Cleaning and Correcting the Alignment for Moving & Fixed Arcing Contacts
Checking Of Spring Snatch Gap and Will Be Aligned Correctly (I.E. Should Not Be More Than 5(+/-1) Mm).

Verification, Cleaning and Functional Checking of Circuit Breaker Is Done.
Inspection, Cleaning and Checking of the Insulation Value for DC Operating Coils.
Cleaning of Vacuum Circuit Breaker with CRC-226 and Removal of old grease and re-greasing the same with recommended grease
Alignment Checks for Draw-In and Draw-Out Operations.
Contact Resistance Testing, Time Testing, Vacuum Travel.
Dismantling, Cleaning, Spare replacement, Making Fine Through by Applying Rubbing Articles, Also Applying Jellies for The Fixed Contacts and Interrupting Chambers and Re-Fixing the Same.

Cleaning Up of Breaker with Cotton Waste and Then Cleaning By CTC/CRC-226
Cleaning Of Old Grease and Applying New Grease for Moving Parts Except Electrical Parts
Check The Tightness of All Parts of Breaker
Checking The Reset Mechanism and Ensure the Tripping Through Push Button
Check And Adjust the Freeness of Trip Release Rod
Check And Clean the Condition of Arc Chute
Check The Gap Between Fixed And Moving Contacts
Check The Condition of Arc & Main Contacts

Check The Condition and Alignment of Jaw Contact with Cradle Terminals
Check And Ensure Proper Closing of All Poles Together
Check The Condition of Control Wiring and Replace It If Necessary
Check The Operation of Racking Mechanism and Lubricating the Same
Check The Under Voltage / Shunt Release Coils
Check The Tightness of All Control Wiring Terminals and CT Wirings
Check The Auto Operation of Spring Charging Motor and Its Limit Switch
Check The Continuity and Proper Changeover of Aux Contact Block Insulation resistance, Contact Resistance Testing, Time Testing and primary Injection testing with ETU test.

Operation Of the Mechanism Both Electrical and Manual
Verification, Cleaning and Functional Checking of Circuit Breaker & Apply Lubrication Grease at Required Place
Testing And Checking of Auxiliary Contacts, Limit switches, Micro Switches, Alpha Plugs, Density Switch (Or) Pressure Gauge, Service & Mechanical Interlock.
Verification Of Tripping & Closing Mechanism and Apply Lubrication Grease at Required Place
Inspecting, Cleaning and Checking of The Insulation Value for Dc Operating Coils
Verification Of Spring Charging Gears & Motor
Inspecting And Testing of Tightness for All Control Cables and Conducts

Check The Gas Pressure, If Low, Build Up Pressure
Checking Of All Insulation Resistance
Thorough Checking of Sf6 Gas in Pressure Gauge (Or) Density Switch
Alignment Checking for Draw-In and Draw-Out Operations.
Dismantling, Cleaning, Making Fine Through by Applying Rubbing Articles, Also Checking Conduct Spring Tension & Applying Jelly for Isolating Conduct & Re-Fixing the Same.
Verification of All Required Alignments
Contact Resistance Testing, Time Testing,

Operation of the Mechanism both Electrical and Mechanical.
Complete Checking, Cleaning, And Testing of Switchgear Through Testing and Checking of Contacts, Limit and Micro Switches, Alpha Plugs, Secondary Pins, Moving & Fixed Contacts, Interrupting Chambers & Other Insulated Parts.
Verification of Required Alignments.
Inspection and Testing of Tightness of All Control Cables and Isolating Contact Tightness.
Verification of Tripping and closing Operations.
Checking Of Insulation Resistance, Contact Resistance Testing, Time Testing.

Checking Of Pole Assembly, Connecting and Conducting Live Terminals and The Drain Out Way Will Be Cleaned Fine.
Verification, Cleaning and Functional Checking of the Circuit Breaker.
Checking Of the Transformer Oil & Replacing the Same If Required.
Alignment Checks for Draw-In and Draw-Out Operations.
Checking Of Moving and Fixed Contacts.
Dismantling, Cleaning, Making Fine Through Applying Rubbing Articles, Applying Jellies for the Fixed Contacts & Interrupting Chambers & Re-Fixing the Same.