Medium Voltage Switchgear (MV SWG) Preventive Maintenance & Checklist

What is a Medium Voltage Switchgear (MV SWG)?

MV Switchgears are developed, manufactured, and tested to switch, protect, and control alternating current systems ranging from 1 kV to 52 kV in accordance with the IEC 62271-200 standard. 

Furthermore, medium voltage switchgears enable the control and usage of energy. MV switchgears take responsibility for interrupting the system’s current in the event of a sudden current spike or short circuit.

There are various switchgear types that include medium voltage equipment which includes 

• Circuit Breakers, 
• Disconnector Switches, 
• Current and Voltage Transformers 

for the incoming, outgoing, transformer supply, and measurement needs of facilities or distribution companies

Medium Voltage Switchgear is utilized in all industries that require medium voltage energy, including power generation, distribution centers, renewable energy plants, industrial facilities, buildings, & railroads.

Medium Voltage Switchgear Preventive Maintenance

Preventive maintenance for medium voltage switchgear ensures that electrical distribution systems operate reliably and safely. 

It entails routine inspections, cleaning, testing, & component replacements to avoid failures, extend equipment life, and maintain system efficiency. 

Proper maintenance reduces downtime and improves electrical safety.

The time required to analyze and maintain medium voltage switchgear in stations is determined by a number of factors, including the type of switchgear, its age, & the climatic conditions. However, there are certain general rules to follow:

• Maintenance for newly installed MV switchgear normally lasts 3-5 years.
• As the switchgear ages, the maintenance schedule should be gradually shortened to 2-3 years.
• In severe environments, regular maintenance & review may be required.
• To obtain exact recommendations & requirements for your individual equipment, go to the manufacturer’s medium voltage switchgear manual.

What is the average station MV switchgear review and maintenance time?

Following to the prescribed MV switchgear maintenance interval is essential for various reasons.

• Maintaining reliability: Regular maintenance assists to keep the switchgear running smoothly, reducing the chance of unexpected malfunctions and outages.
• Increasing safety: Regular maintenance ensures that the switchgear runs safely, lowering the risk of accidents & protecting persons and equipment.
• Extending equipment life: By following the specified maintenance schedule, you can avoid early wear and tear and extend the life of the MV switchgear.

What are the most important MV switchgear maintenance components?

During MV switchgear maintenance, various major components must be inspected and reviewed to maintain optimal performance and safety. Several of these components include:

• Circuit Breakers: Inspect for wear, correct operation, and lubricant. Check their protective settings to make sure they are working properly.
• Busbars & Connections: Check for corrosion, overheating, and loose connections, and tighten or replace them as needed.
• Protective Relays & Control Systems: protective relays & control systems to ensure they are operational and calibrated properly.

How can I learn medium voltage switchgear maintenance?

Read the manufacturer’s MV switchgear manual for maintenance, scheduling, and safety.

Gain practical experience by attending manufacturer or industry training courses or seminars.

Monitor industry trends, standards, & guidelines via professional associations, conferences, & publications.

How can MV SWG maintenance overcome frequent issues?

To achieve a simple procedure, medium voltage switchgear maintenance must solve many problems. Challenges include:

• Insufficient Resources: Make sure you have enough skilled workers, tools, and equipment to finish maintenance safely.
• Limited Downtime: Run maintenance during low demand (or) planned outages to minimize facility disruptions.
• Environmental Factors: Protect switchgear and workers from dust, moisture, and high temperatures.

MV SWG Preventive Maintenance

Moving Parts Preventive Maintenance

Electrical systems need preventive maintenance of moving parts for reliability, efficiency, and longevity. 

• A dry, clean cloth should be used to remove dust from the poles’ insulating shell to prevent contamination & insulation failure. 
• Check plugging-in clamps occasionally to avoid improper electrical connections. 
• To guarantee functioning and grounding, inspect the earthing switch device, including clamps & contact jaws.

Functional Unit Maintenance

Maintaining the functional unit requires checking for attachments like levers and inspecting the outside for cleanliness and oxidation. 

• Clean exterior surfaces with a dry cloth to eliminate dust and grime. 
• Mechanical integrity requires checking cover, wiring duct, and electrical connection tightness. 
• Repeated actions should test mechanical controls for smooth operation. For accuracy, check open & closed position status indicators. 
• Test key lock mechanical locking systems to prevent unauthorized (or) unintentional activation. 
• Clean interior mechanical components without solvents and check threaded fasteners & internal stops for secure fastening. 
• Periodic solvent cleaning and lubricating of mechanical parts reduces wear and ensures smooth movement. 
• Check the look of mechanical parts and connections for degradation. Test functional mechanical interlocks for safety and appropriate operation.

Moving Part Compartment Maintenance

Periodic inspection and maintenance ensure shutters operate smoothly during plugging-in and withdrawal. 

• Plugging-in electrodes must be checked for wear and oxidation. 
• Insulating parts must be wiped with a dry cotton cloth to retain dielectric strength. 
• Regular cleaning and lubrication reduce friction-related damage in mechanical components. 
• Electrical power contacts should be checked for integrity and conductivity. 
• Plugging-in electrodes should also be checked for overheating (or) discharge, which could signal electrical system problems.

Busbar Maintenance

• Checking busbar connections for loose joints can prevent overheating and electrical problems. 
• Clean insulators, connectors, and supports to maintain insulation & electrical efficiency. 
• The compartment’s leak tightness needs to be checked to prevent moisture from compromising electrical insulation. 
• Visually inspecting internal components for system performance issues is also recommended.

HV Cable Compartment Maintenance

• High-voltage cable compartments must be inspected regularly to protect key components. 
• Check earthing switch contacts for appropriate grounding and safety. 
• Assess compartment tightness to avoid accidental disconnections. 
• Clean insulators, connectors, & supports to maintain electrical performance. Cable terminations must be checked for insulation & secure connections. 
• Clean and lubricate compartment mechanical parts for smooth operation. 
• Visual inspections should also detect wear, damage, and future failure.

Low Voltage Box Maintenance

• To ensure performance and reliability, the low-voltage box needs periodic internal component examination. 
• To avoid electrical problems, check terminal and other electrical connections.
• Wiring & relays must be checked for wear and deterioration that could influence system performance. 
• Maintaining the low-voltage box is essential for control & protection system stability.

Moving parts & electrical components need preventive maintenance to improve system reliability, reduce downtime, and extend equipment life. 

Following preventive maintenance schedules maintains operational safety & reduces electrical distribution system breakdowns.

Checklist