Introduction
VCB breaker is very critical component in medium voltage electrical system. VCB breaker offering reliable protection against fault currents. Due to low maintenance requirement they are widely use in electrical power system. The service life of VCB breaker is very long time. If the breaker are not maintaining in a timely manner it can also increase your downtime. If you want to prevent costly downtime and want high service life of breaker so it is very important to maintain it. The better the preventive maintenance of the VCB breaker its service life will be longer. Preventive maintenance is essential for a breaker to perform well.
Why Preventive maintenance is essential?
Preventive maintenance is very important for equipment's. without it equipment's will not perform well. For reliable and save operations of breakers for longer service preventive maintenance is must as per their schedule. Preventive maintenance is essential for operational reliability and personnel safety. Doing this will minimize risk and can save from unexpected failures.
When should preventive maintenance be done?
The first of these is the manufacturer recommendation. Then the operating environment is looked at. Is the operating environment not that of the dusty, humidity and corrosive atmosphere? After that the verify of numbers is applied to his switching operation. The condition of its electrical load is checked. Visual inspection should be done every six months. It should have a comprehensive maintenance plan after 2,000 to 10,000 switching operation or within 2 to 5 years.
What are the things to consider before performing preventive maintenance?
Before starting maintenance it is important to keep the following in mind.
1-First the breaker must be isolated from main power source and must be follow LOTO (lockout/tagout) procedure.
2-The existing storage energy must be completely discharged (springs, capacitors)
3- To check weather the power supply has been completely cut off or not this should be confirmed with voltage detector.
4- In keeping with safety protocol wear personnel protective equipment (PPE) as requirement.
Preventive maintenance step by step procedure
1- Visual inspection
- For visual inspection must be checked it sign of dust, corrosive surface and moisturizing.
- Must be checked it control circuit wiring and terminal checking for properly tightness or damaged
- Must be looked at loose bolts.
2- Mechanical checks
- First breaker to be operated manually for several times for verify its smooth operation.
- Must be inspected its moving parts like linkages, levers, rollers for wear or misalignment.
- Must be checked its operation and condition of spring charging mechanism.
- Must be checked its trip and close mechanism operate correctly.
3- Electrical testing
- Contact resistance test must be performed for ensured its minimal resistance at breaker contacts.
- Must be performed insulation resistance test to ensured its pole to pole and pole to earth insulation integrity.
- Breaker timing test must be performed to ensured its opening and closing timing for consistency.
- To ensured dielectric strength Hipot test must be performed.
4- Vacuum interrupter
- To verify its vacuum interrupter integrity used a vacuum bottle for ensured the integrity of vacuum interrupter.
- Must be inspected the sign of contacts erosion and must be replaced interrupter if the wear limit is reached.
5- Lubrications and cleaning
- Clean the dust and contaminated portion using vacuum cleaner or dry lint free cloth.
- Ensured that do not use compressed air because it may forced dust into breaker sensitive components.
- As per manufacturer recommendation lubricate the breaker moving parts.
6- Control circuit
- Must be checked its all auxiliary relays, coils supply and trip circuit supply.
- Must be verified its operation of indicators, interlocks and safety features.
- Must be checked the properly function of spring charging motor.
Comments
Post a Comment