What are the technical parameters of a general-purpose current transformer?
Jul 24, 2026| 1. Basic Adaptation Parameters
Rated Voltage: Must match the voltage of the power grid, typically 0.66kV, 10kV, etc., to ensure insulation withstand capability.
Rated Frequency: Commonly 50Hz in China, partially compatible with 60Hz scenarios.
2. Core Current Transformation Parameters
Rated Primary Current: Typical range 5A~5000A, must be greater than the maximum load current of the circuit.
Rated Secondary Current: Domestic standard is 5A or 1A, 1A is more suitable for long-distance transmission.
Rated Current Ratio: The ratio of primary to secondary rated currents, such as 30/5, 100/5, etc.
3. Accuracy and Load Parameters
Accuracy Class: Commonly 0.5 and 1 class for measurement, 5P and 10P class for protection.
Rated Capacity: Unit is VA, commonly 2.5VA, 5VA, 10VA, determines the load capacity of the secondary side.
4. Withstand and Protection Parameters
Rated Short-Time Thermal Current: The maximum thermal shock current that the instrument can withstand within a specified time.
Rated Dynamic Stability Current: The peak electrodynamic current that the instrument can withstand, ensuring the stability of the mechanical structure.
Accuracy Limit Factor: A parameter used for protection; for example, 10P20 means that the error will not exceed 10% at 20 times the rated current.
Instrument Safety Factor: A parameter used for measurement, to prevent damage to the instrument due to excessive secondary output during a fault.
