What Are Current Transformers (CTs)?
Current transformers (CTs) safely reduce high electrical currents into measurable signals for sub‑meters, monitoring equipment, and energy management systems.
Start NowHow Current Transformers Work
CTs produce a proportional secondary signal that mirrors primary current flow without interrupting the circuit.
Primary Conductor
The live cable acts as the primary winding, carrying the full load current through the CT aperture.
Magnetic Induction
Current flow generates a magnetic field that induces a proportional secondary output.
Secondary Output
The CT outputs a scaled current or voltage suitable for meters and monitoring devices.
Electrical Isolation
CTs electrically isolate measurement equipment from high‑voltage conductors for safety.
Signal Proportionality
The secondary signal remains directly proportional across the CT’s rated operating range.
Meter Interface
CT outputs connect directly to sub‑meters, analysers, or energy management systems.
Our Related Current Transformer Products
Current Transformers (CTs)
A current transformer (CT) is a type of current transducer that steps down high electrical current to a smaller, safe, proportional signal for measurement.
View CTsWhy CTs Are Used in Energy Sub‑Metering
CTs enable accurate measurement of high‑current circuits without direct electrical connection.
- Measure large currents safely
- Enable retrofit installations
- Support flexible system design
- Improve installation safety
- Allow scalable monitoring architectures
Types of Current Transformers
Different CT designs suit different installation environments and monitoring requirements.
Split‑Core CTs
Openable cores allow installation without disconnecting cables, ideal for retrofit projects.
Find Out MoreSolid‑Core CTs
Solid core CTs are available in a wide range of types and sizes and are generally used in new build panels.
Find Out MoreRogowski Coils
Flexible coils measure very high currents without magnetic saturation risks.
Find Out More333 mV Output CTs
Low‑voltage CTs eliminate open‑circuit risk and simplify installation.
Find Out MoreSpecialist CT Designs
Custom CTs support confined spaces, busbars, and irregular conductor arrangements.
Find Out MoreReady to discuss your project?
Our technical team provides free pre- and post-sales support from specification through to commissioning.