CT & VT Testing
Precision Testing for Current and Voltage Transformers
We offer professional CT and VT testing for high and low voltage systems across the UK. Our service ensures your current transformers (CTs) and voltage transformers (VTs) are performing accurately and safely under real-world conditions.
Why CT & VT Testing Matters
CTs and VTs are critical for protection, metering and control systems. Any error in their operation can lead to incorrect readings, delayed trips or equipment failure. Our testing verifies their performance and confirms they meet required accuracy classes.
We carry out:
- Ratio and polarity checks
- Excitation and insulation resistance tests
- Burden and secondary circuit verification
- Accuracy class and performance validation
- Primary injection for in-service testing
We use calibrated, high-precision instruments to ensure every test result is accurate and fully traceable.
Applications
Our CT and VT testing services support a range of industries and network configurations. Whether commissioning new equipment or maintaining existing assets, we help ensure safe and reliable system operation.
Common test sites:
- Substations and switchboards
- Protection and metering panels
- Generator and transformer circuits
- Industrial power systems
- Renewable and battery systems
All testing is followed by a detailed report for compliance and maintenance records.
Frequently Asked Questions
What is CT and VT testing?
It checks the accuracy and condition of current and voltage transformers, which are used in protection and measurement systems.
When should these be tested?
During commissioning, after system changes, and as part of regular maintenance to ensure continued accuracy and reliability.
Do you test both standalone and built-in CTs and VTs?
Yes. We test both standalone units and those integrated within switchgear or equipment.
Will I get a report?
Yes. A report includes ratio test results, polarity checks, burden values and confirmation of compliance with the required accuracy class.