The CT (Current Transformer) ratio is the ratio of the primary current input to the secondary current output at full load.
Understanding CT Ratio
The CT ratio is a crucial parameter for current transformers, indicating the relationship between the current flowing in the primary winding and the current produced in the secondary winding. This ratio allows the transformer to accurately step down high primary currents to lower, measurable levels for monitoring, metering, and protection purposes.
For example, according to our reference, a CT with a ratio of 300:5 is rated for 300 primary amps at full load and will produce 5 amps of secondary current when 300 amps flow through the primary.
Key Aspects of CT Ratio:
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Definition: The ratio of primary current to secondary current at full load.
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Significance: Enables the measurement and monitoring of high currents by scaling them down to manageable levels.
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Example:
Primary Current (Amps) Secondary Current (Amps) CT Ratio 300 5 300:5
Practical Implications:
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Metering: Allows accurate measurement of current in high-current circuits.
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Protection: Provides current signals for protective relays to detect faults and initiate protective actions.
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Monitoring: Facilitates the monitoring of current levels for operational control and diagnostics.
