Comprehensive Guide to Industrial Transformer Repair Procedures

The repair of transformers in industrial zones requires extensive understanding of maintenance and routine inspection processes. Both minor and major overhauls necessitate technicians possessing high skill levels and compliance with strict standards.

Transformer Overhaul: Procedures and Techniques

To ensure the durability and performance of transformers, conducting both minor and major overhauls is essential. Minor tasks include checking insulation and replacing defective parts. Major overhauls involve dismantling, cleaning, and replacing all components according to a detailed plan, ensuring all electrical equipment operates correctly.

Overhauls are critical to maintaining the stability and efficiency of electrical systems. The minor overhaul focuses on small repairs without dismantling the core, while major tasks involve:

1. Minor exterior repairs and cleaning relevant parts like bushings.
2. Draining sludge, refilling auxiliary oil tanks, cleaning gauges, and checking oil levels.
3. Replacing silica gel in thermal and breathing tanks.
4. Inspecting valves, seals, cooling systems, and bearings of cooling fan motors.
5. Examining protective devices and surge arresters, alongside the automatic voltage control device.
6. Cleaning bushings and changing oil in panel separations for open-type transformers.

Major overhaul involves a more complex process, aimed at restoring or completely reconstructing the system. Main types include periodic and restorative overhauls:

• Periodic overhaul: Disassembly and drying of the core, comprehensive inspection and repair.
• Restorative overhaul: Focus on repairing or rewinding coils, reconstructing the iron core and damaged insulation.

Steps in major overhauls:

1. Power off and drain all oil from the transformer.
2. Disassemble the core and meticulously inspect each part.
3. Draft a repair or replacement plan, including coil rewinding and iron core restoration.
4. Reassemble and dry the unit to remove moisture.
5. Perform insulation resistance testing and load tests.

Safety protocols such as power disconnection and grounding must be adhered to in both overhaul processes. Comprehensive ceramic insulator cleaning and oil quality assessment are essential for machine condition evaluation. Skilled technicians must carry out transformer repairs to ensure safety and efficiency.

The primary aim of minor and major transformer overhauls is to restore and improve the original technical specifications, enhancing durability and operational safety, thus ensuring optimal power grid performance.

Routine Maintenance and Repair Process for Transformers

Regular transformer maintenance is a crucial task to extend the life of the equipment. Repair processes include routine checks and mechanical and electrical component maintenance. Techniques like insulating oil replacement and surface cleaning ensure smooth, efficient transformer operation. Frequent electrical checks help detect any anomalies early on before they escalate into major problems.

Ensuring the efficient and stable operation of transformers is a top priority for business leaders in the electrical industry. The typical maintenance process involves intricate technical steps, from periodic checks to scheduled repairs, aimed at prolonging lifespan and maintaining optimal performance.

1. Periodic Checks

   Conducted every three months, periodic checks include:

   • Checking oil levels in the main and auxiliary tanks to ensure effective insulation and performance.
   • Replenishing silica gel in moisture traps upon color change to prevent moisture ingress.
   • Timely detection and resolution of oil leaks, ensuring machine performance is unaffected.
   • Thorough documentation of inspection results in a maintenance log for monitoring transformer condition.

2. Routine Maintenance

   Scheduled every six months or as prescribed, routine maintenance involves:

   • Complete transformer cleaning, covering components like cooling fans, magnetic cores, and high-/low-voltage connections.
   • Securing cable connections to ensure good contact, thus improving performance.
   • Monitoring and evaluating operational temperature to prevent overheating.
   • Testing insulating oil samples to avoid insulator failure.
   • Inspecting insulation levels across components to identify potential risks.
   • Cleaning other parts such as bushings, control cabinets, and circuit boards to maintain stability.

3. Periodic Overhaul

   Conducted every 8 to 12 years, periodic overhauls are critical:

   • Replacing insulating oil to ensure dielectric quality.
   • Drying transformers to remove moisture as per technical standards.
   • Disassembling for comprehensive inspection, repair, and part replacement.
   • Testing all specifications to ensure readiness for normal operation.
   • Cross-verifying technical data with operational records for accurate equipment assessment.

4. Other Critical Operations

   Supplementary important activities in transformer maintenance:

   • Surveying and analyzing operational status to assess overall performance.
   • Consulting and station site improvements for long-term stability.
   • Cleaning and securing terminals and cable connections to prevent contact issues.
   • Monitoring oil temperature and control system performance for early detection of anomalies.

This routine maintenance and repair process not only ensures efficient transformer operation but also extends equipment life and saves unexpected repair costs.

Periodic Evaluation and Inspection of Industrial Transformers

Regular assessment of transformer conditions via dielectric system and electrical component inspections is necessary for stable operations. This involves measuring performance decline to plan timely maintenance or repairs. Repair processes in industrial zones aim to minimize fault risk, ensuring production continuity.

Regular inspection and evaluation of transformers in industrial zones according to Circular 33/2015/TT-BCT regulations are mandatory. This includes vital steps to secure transformer lifespan and peak performance.

Inspection and Maintenance Process

Transformer inspections and maintenance follow a detailed process, including assessment of the exterior like casing and signs of corrosion:

• Insulation resistance, coil resistance, and dielectric strength are measured for industrial electrical safety.
• The operation of protective parts and safety mechanisms is also checked for performance optimization.

Types of Transformer Inspections

Transformer inspections fall into initial, periodic, and exceptional categories:

1. Initial Inspection: Conducted before transformer operation begins.
2. Periodic Inspection: Takes place every 36 months for transformers and related electrical devices.
3. Exceptional Inspection: Required by authorities or after incidents.

Scheduled Maintenance

Routine transformer maintenance occurs every three months (check) and six months (service). This includes checking dielectric oil levels (MOG), examining oil leaks, and replacing moisture-absorbing materials according to color change.

Inspection Frequency

The inspection frequency for transformers is based on capacity and operating conditions:

• Transformers above 3150 kVA in unattended stations need checks at least every 10 days.
• Smaller transformers can be checked more flexibly, potentially monthly or quarterly, depending on installation location.

Detailed Inspection Content

During inspections, items checked include:

• External equipment reviews, structural reinforcement parts.
• Insulation resistance and contact resistance measurements.
• Leakage current and dielectric strength assessments.
• Parameter checks of protective devices and speed regulators.

Inspection methods generally involve direct observation and specialized equipment to ensure accuracy and safety.

Investing in transformer repair procedures within industrial zones not only ensures technical efficiency but also optimizes long-term operational costs. Regular inspection and accurate maintenance processes significantly limit unexpected breakdowns, boosting system credibility and effectiveness.

For optimal transformer performance and safety, contact QuangAnhcons via our Hotline: +84 9 1975 8191 for detailed consultation.

QuangAnhcons offers professional transformer maintenance and repair services, meeting international standards and ensuring safety in execution, thus optimizing operations in industrial zones.