Can a damaged coil be repaired, refurbished or replaced?
Low and medium voltage coils which have been damaged can be repaired, refurbished or replaced. Repairing involves fixing the issue without removing the coil from the core. This may be an option for transformers which have sustained much physical damage or if an issue such as lowering insulation levels is diagnosed before actual failure. This may also be possible for transformers which are dirty or have been submerged. In some cases the the coil can be removed and refurbished. This would typically be done for larger, often medium voltage transformers which have sustained damage to the outer, primary winding. The last option is to replace the coil entirely which is often done if the coil is severely damage, the inner winding is damaged or the transformer can’t be sufficiently cleaned.
While coils can be repaired, refurbished and replaced, this must be compared to the cost of providing a new unit. Repairs must factor in additional transportation and testing costs, higher disassembly and assembly costs, core damage and replacement and the benefits of using a new transformer, often with modern higher efficiencies. Repair is often only practical for large custom transformers.