Repairing and servicing transformers is crucial for maintaining their operational efficiency, reliability, and safety. Transformers can experience issues over time due to factors such as aging, environmental conditions, electrical stresses, or manufacturing defects. Here is a general guide for the repairing and servicing of transformers:

Initial Assessment:

1. Visual Inspection:

   • Inspect the external condition of the transformer for physical damage, leaks, or signs of overheating.
   • Check for any loose connections or components.

2. Oil Analysis:

   • Collect oil samples for analysis to assess the condition of the insulation and detect any contaminants.
   • Evaluate the dissolved gas analysis (DGA) results to identify potential issues.

3. Electrical Testing:

   • Perform electrical tests such as insulation resistance, turns ratio, power factor, and impedance tests.
   • Identify any abnormal electrical parameters.

Repairing:

1. Identification of Faults:

   • Analyze diagnostic test results to pinpoint specific faults or issues.
   • Determine whether the faults are related to the core, windings, insulation, or other components.

2. Core Repairs:

   • Repair or replace damaged core laminations.
   • Address any issues related to the core structure, such as tightening clamping structures.

3. Winding Repairs:

   • Repair damaged windings, addressing issues such as short circuits or insulation breakdown.
   • Re-varnish or re-insulate windings as necessary.

4. Tap Changer Repairs:

   • Repair or replace faulty tap changer components.
   • Lubricate moving parts and ensure proper functionality.

Servicing:

1. Oil Treatment:

   • Purify the transformer oil to remove contaminants.
   • Treat the oil for proper dielectric strength.

2. Gasket and Seal Replacement:

   • Replace gaskets and seals to ensure a proper seal and prevent oil leaks.

3. Lubrication:

   • Lubricate moving parts such as tap changers and cooling system components.

4. Tightening Connections:

   • Check and tighten electrical connections to prevent overheating and ensure proper conductivity.

Safety Considerations:

• Always follow safety procedures and guidelines during the repair and servicing activities.
• Disconnect and de-energize the transformer before initiating any work.
• Use appropriate personal protective equipment (PPE) and safety measures.

It's essential to approach transformer repair and servicing systematically, considering the specific requirements and guidelines provided by the transformer manufacturer. Consulting with experienced professionals and adhering to industry standards is crucial for ensuring the effectiveness and safety of the repair and servicing processes.