A current transformer (CT) is a type of electrical device used to convert high voltage currents into a low-voltage current that can be monitored by a standard ammeter. It is an important part of an electrical system and needs to be properly selected for your application. It is not as complex as a voltage transformer but there are some differences that you should be aware of when making your choice.

Current transformers consist of a primary winding, a secondary winding and a core. The core is usually made of a lamination of silicon steel to obtain good accuracy. There are different types of cores that can be used depending on the design and application of a CT. There are also various types of insulation materials that can be used in a current transformer. Some examples include PTFE, PVC, and EPR.

The principle of operation of a current transformer is to produce a magnetic flux on the primary side through a series connection. This magnetic flux then links with the secondary side through mutual induction. The resulting current in the secondary is proportional to the current in the primary. The secondary winding is connected to a standard ammeter that can then be read.

High voltage currents are very dangerous and require special equipment to handle them. A current transformer is used to monitor these high currents by separating measurement and protection circuits from the actual high voltages and currents present in the system. It is used in areas where the AC instrument coil or metering system cannot be built to withstand the high currents being passed through them.

When a current transformer is correctly installed, it will provide a current to the metering system that is proportional to the current passing through the primary winding. It is a simple device that can be used to monitor power in a variety of applications, including metering and load surveys.

Current transformers are also useful in protecting devices from overvoltages by separating the measurement and protection circuits. This is achieved by observing the voltages and currents at several points in the system and connecting the measuring or control devices to the secondary of the CT. This will prevent damage to the device and reduce potential hazards in the system.

ENTES offers a wide range of CTs that are available in a variety of sizes and specifications to suit your specific requirements. They are commonly used in medium voltage (MV) installations and work in conjunction with protective relays and metering systems. Our MV compatible CTs are also available in a split core configuration and can be mounted to existing or new systems without the need for additional relay mounting. They can be used in power metering, demand metering and energy research applications and are compatible with industry standard power meters. For more information, please feel free to contact us. We would be happy to help you select the right current transformer for your application.