Buy clamp-on current transformers online
Clamp-on current transformers are the standard solution for indirect current measurement in switchgear, energy monitoring and billing-related applications. At Stromwandler24 you can compare common current ranges, accuracy classes and secondary currents for your project.
Typical applications
- Current measurement in switchgear and sub-distributions
- Transformer-operated measurement with energy meters
- Applications with clear accuracy and burden requirements
Select the right model
Important selection criteria are the nominal current, the conductor opening, the required accuracy class and whether the transformer is used for monitoring or billing. If you need support choosing the right model, our guide and product overview are the fastest entry points.
Need a broader overview? Current transformers and measurement technology.
Busbar vs cable transformers
| Criterion | Busbar CT | Cable CT |
|---|---|---|
| Mounting | On flat/round busbar | Around cable |
| Current range | 5 A – 4000 A | 5 A – 1000 A |
| Typical use | Main distributions | Sub-distributions |
| Accuracy | Up to class 0.2s | Up to class 0.5s |
Frequently asked questions
What secondary current should I choose — 1 A or 5 A?
5 A is standard for short cable runs (up to 10–15 m). For longer distances to the meter or energy management system, 1 A reduces transmission losses and allows cable lengths up to 50 m.
What accuracy class do I need for MID billing?
For legally compliant billing, accuracy class 0.5s is typically required. For internal monitoring, class 1 is sufficient.
Can I retrofit a clamp-on CT without breaking the circuit?
Clamp-on CTs require the conductor to be threaded through the core window. If you cannot disconnect the conductor, consider a split-core (hinged) CT instead. Learn more about split-core CTs