High-Precision FK Series Current Transformers from China Suppliers and Factory for Safe Power Monitoring

Unlike direct current measurement methods, which risk damaging sensitive devices or endangering personnel when exposed to high primary currents, the FK series CT provides galvanic isolation between primary and secondary circuits. This isolation eliminates direct electrical connectivity, mitigating overload risks and ensuring compliance with electrical safety standards for both equipment and operators.

The FK series CT operates on the mutual induction principle, leveraging a closed magnetic core (typically constructed from silicon steel or amorphous alloy for low magnetic loss) with two concentric winding sets:

The CT adheres to the ampere-turn balance relationship:

This relationship ensures the secondary current is a fixed, scaled fraction of the primary current. The FK series CT is standardized to common secondary output ratings of 1 A or 5 A AC—values compatible with virtually all industrial ammeters, power meters, and protective relays.

The FK series CT is indispensable in the following electrical system applications:

• Power System Monitoring: Paired with digital ammeters, power meters, and energy meters to measure primary currents ranging from tens to thousands of amps (e.g., generator output current, distribution feeder current, industrial motor load current).
• Protective Relaying: Integrated with overcurrent, short-circuit, and earth-fault relays to trigger fast, selective tripping of circuit breakers during fault conditions, preventing equipment damage and system downtime.
• Industrial Process Control: Used in motor control centers, switchgear, and automation systems to provide current feedback for load regulation, overload protection, and process optimization.
• Revenue Metering: Deployed in utility-grade metering systems to ensure accurate, traceable current measurement for energy billing purposes.