The instrument transformer, also known as the instrument current transformer, is a very specialized type of electrical component that is used to transform voltage or current levels in a system. It can also be used to provide isolation.
The ability to transform and lower current and voltage to lower current and voltage is essential in the use of power for instruments of all types, as well as in metering applications. In these types of applications, the primary winding is connected to the high voltage or high current part of the circuit, and the secondary winding is then connected to the instrument, which is a meter or relay in many applications.
The instrument current transformer can be found in many different types of systems. They can be used in all types of AC power systems for measurement, and they are also used to protect the power system and the instrumentation without the use of complex protective systems that would be costly to produce.
Measuring the main AC power system voltage would be extremely difficult as the high voltage and current would require extremely costly and complex metering and monitoring systems.
Through the use of the instrument current transformer , the voltage and current can be very effectively dropped down to a much lower level that is compatible with lower cost measuring devices. As the ratio of step down is known and is standardized in the transformers, these measuring systems are able to meter and monitor the main AC voltage and current with high degrees of accuracy.
At the same time, these transformers provide isolation, keeping the high voltage and the sensitive measurement equipment separate in the system. This extends the life of the measuring systems used in power grids and also reduces the need for additional protective circuits within the various instruments.