What is IEC 60357?

IEC 60357 is an international standard that specifies the basic requirements for instrument transformers used in electrical power systems. These instruments play a crucial role in measuring and monitoring various electrical quantities such as voltage and current. The standard ensures the accuracy, reliability, and interoperability of instrument transformers across different manufacturers and countries.

History and Development

IEC 60357 was first published by the International Electrotechnical Commission (IEC) in 1989. It replaced several national standards and aimed to establish a universal set of guidelines for instrument transformers. Since then, it has been regularly updated and revised to keep up with the advancements in technology and changing industry requirements.

Main Requirements

The standard covers a broad range of technical aspects related to instrument transformers. It specifies the design, construction, and testing requirements that manufacturers must adhere to in order to ensure reliable and accurate performance. Some of the key requirements include:

Accuracy classes: Instrument transformers must be classified into different accuracy classes, ranging from 0.1 to 10. These accuracy classes define the maximum permissible error under specified operating conditions.

Insulation levels: The standard outlines the minimum insulation levels required to withstand high voltages without any breakdown or damage.

Thermal performance: Instrument transformers must be capable of handling the generated heat and dissipating it safely to prevent overheating.

Impulse voltage withstand capability: They should be able to withstand sudden surges of high voltage without experiencing any physical or electrical damage.

Benefits and Applications

Adhering to IEC 60357 provides several benefits. First and foremost, it ensures that instrument transformers from different manufacturers can be seamlessly integrated into electrical power systems without any compatibility issues. This enables utilities to have a wide range of options when selecting equipment, promoting healthy competition among suppliers.

Additionally, the standard guarantees accuracy and reliability in measuring electrical quantities. Accurate measurements are vital for various purposes, such as billing customers correctly, monitoring system performance, and detecting any abnormalities or faults in the network.

IEC 60357-compliant instrument transformers find applications in various areas, including power generation, transmission, and distribution systems. They are used for protective relaying, metering, revenue metering, fault recording, and other critical functions in electrical power networks.

In conclusion, IEC 60357 is a comprehensive international standard that sets the requirements for instrument transformers in electrical power systems. Its adherence ensures the accuracy, reliability, and interoperability of these instruments across different manufacturers and countries. By providing a common set of guidelines, the standard promotes healthy competition, facilitates equipment integration, and guarantees accurate measurements in electrical power networks.