What is the role of Current Transformers (CTs) in Energy Metering?

Current transformers (CTs) reduce high electrical currents to a manageable level for energy meters. They are essential for measuring large loads safely and accurately. CTs are classified by their ratio (e.g., 100:5A), which determines the output current relative to the primary current.

Current Transformers must be installed correctly based on orientation, burden matching and secondary circuit considerations. Orientation refers to correct polarity (P1 facing the source) ensures accurate readings. Burden Matching refers to the CT’s burden (VA rating) which should match the meter’s requirements to avoid measurement errors. Secondary Circuit Considerations refers to the secondary side which should never be left open to prevent high voltage buildup.