Service
Transformer bushing repair & replacement
Diagnosis, repair and replacement of transformer bushings — one of the most violent causes of catastrophic failure.
Bushings carry the connections through the transformer tank, and their failure is one of the most violent and destructive — often ending in explosion and fire. TEVKO diagnoses, repairs and replaces bushings of any manufacturer, detecting deterioration of the capacitive insulation before it becomes catastrophic.
A bushing is the insulated feedthrough that carries a high-voltage connection through the grounded tank. In condenser (capacitive) bushings, layers of insulation manage the electric field, and when that insulation degrades — by moisture ingress, ageing or contamination — the bushing can fail suddenly and violently, one of the few transformer faults that routinely causes explosion and fire. That is why bushings are watched closely and serviced proactively.
Diagnosis is led by power factor (Tan Delta) and capacitance measurement: a rising power factor or a change in capacitance reveals deterioration of the capacitive insulation long before failure. Visual inspection of porcelain, gaskets and oil level complements the electrical test. When a bushing is beyond repair, replacement with a correctly-rated unit — matched in voltage, current and creepage — is the safe path.
TEVKO diagnoses, repairs and replaces bushings on transformers of any manufacturer, measuring with Omicron and Megger instrumentation and interpreting power factor and capacitance against the bushing nameplate and history, under IEEE C57 and IEC 60076. Because a compromised bushing endangers the whole transformer and the people near it, the work prioritizes catching deterioration early and documenting the result.
Scope of bushing service
Diagnosis
Power factor and capacitance testing plus visual inspection to detect deterioration before failure.
When it applies: Routine maintenance and after abnormal events.
Repair / replacement
Repair of serviceable bushings or replacement with a correctly-rated unit when beyond repair.
When it applies: Degraded capacitive insulation, damaged porcelain or gaskets.
How we execute the service
Diagnosis
Power factor and capacitance measurement and visual inspection of each bushing.
Decision
Repair or replace based on the condition of the capacitive insulation and porcelain.
Execution
Repair or installation of a correctly-rated bushing with proper sealing and oil level.
Acceptance testing
Power factor and capacitance verification, documented before return to service.
Frequently asked questions — transformer bushing repair & replacement
Why are bushing failures so dangerous?
Because a bushing carries a high-voltage connection through the grounded tank, and degradation of its capacitive insulation can cause a sudden, violent failure — one of the few transformer faults that routinely ends in explosion and fire. Early detection is critical.
How is bushing deterioration detected?
Mainly by power factor (Tan Delta) and capacitance measurement: a rising power factor or a change in capacitance reveals deterioration of the capacitive insulation before failure, complemented by visual inspection of porcelain, gaskets and oil level.
When is a bushing replaced instead of repaired?
When the capacitive insulation is degraded beyond repair or the porcelain is damaged. Replacement uses a correctly-rated unit matched in voltage, current and creepage distance, then verified by power factor and capacitance testing.
Does TEVKO service bushings of any brand?
Yes. As an independent, multi-brand service provider, TEVKO diagnoses, repairs and replaces bushings on transformers of any manufacturer, interpreting results against the bushing's nameplate and history.
Transformer bushing repair & replacement in images
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