Reliable CT Replacement for Power Transformers
Current transformers (CTs) provide the current measurements used by protective relays, meters, and monitoring systems. When a CT is damaged, deteriorated, or no longer appropriate for the application, it can produce unreliable information and affect the performance of critical protection and control systems.
MVA provides current transformer replacement for utility and industrial power transformers. Our field service team can support the project from initial planning and removal through installation, testing, and final verification.
When Is Current Transformer Replacement Needed?
A current transformer may require replacement because of a failed test, physical damage, insulation deterioration, inaccurate measurements, or changes to the transformer’s protection and metering requirements.
Common reasons for current transformer replacement include:
- Incorrect or inconsistent current readings
- Failed ratio, polarity, or excitation testing
- Deteriorated insulation
- Abnormal winding-resistance results
- Damaged CT leads or terminal connections
- Evidence of overheating or moisture intrusion
- Changes to relay or metering requirements
- An incorrect CT ratio or accuracy class
- Obsolete components that can no longer be supported
- Damage discovered during a transformer inspection or repair
Identifying the reason for replacement helps determine the appropriate CT specifications and the work required to access, remove, and install the component.
CT Replacement for Planned and Unplanned Outages
Current transformer replacement may be scheduled as part of a planned equipment upgrade or required after an unexpected failure. In either situation, outage coordination is essential.
MVA works with the customer to define the replacement scope, confirm equipment requirements, coordinate access, and identify the testing needed before re-energization. When the work affects the transformer’s oil or sealed system, the necessary restoration activities can be incorporated into the project.
Why Choose MVA for Current Transformer Replacement?
MVA has experience completing complex transformer repairs for utility and industrial customers. Our field service team understands how a CT interacts with the transformer’s bushings, internal connections, secondary wiring, protective relays, and metering systems.
Customers rely on MVA for:
- Experienced transformer field technicians
- Careful documentation of existing CT connections
- Coordination with transformer and protection-system requirements
- Installation and post-replacement testing
- Support for power and EHV-class transformers
- Nationwide field service capabilities
- A project scope focused on safe, accurate return to service
If testing has identified a failed CT or you are planning a protection or metering upgrade, MVA can help define the requirements for your current transformer replacement.
Have questions about current transformer replacement, testing, or project requirements? Visit our Current Transformer FAQs to learn more or request a field services quote.
