High Precision FK Series Current Transformer (CT) - Reliable Power Solutions from China Suppliers and Factory

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:

• Primary Winding Consists of a small number of turns (or a single pass-through conductor for bar-type CTs) connected in series with the high-current primary circuit. The primary current (Iₚ) flowing through this winding generates a magnetic flux in the core.
• Secondary Winding Features a large number of precisely wound turns, connected to measuring instruments or protective relays. The magnetic flux induced by the primary winding generates a proportional secondary current (Iₛ) in this winding.

The CT adheres to the ampere-turn balance relationship:

• Nₚ = Number of primary winding turns
• Nₛ = Number of secondary winding turns

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:

• High Measurement Accuracy Classified by accuracy grade (e.g., Class 0.2, Class 0.5, Class 1.0) to meet diverse application requirements—from precision revenue metering to general-purpose monitoring.
• Low Magnetic Saturation The core material is selected to resist magnetic saturation under normal and moderate overload conditions, ensuring linear current transformation and preventing secondary current distortion.
• Robust Isolation Rating Designed to withstand high dielectric voltage between primary and secondary windings, complying with international safety standards (e.g., IEC 61869) for reliable operation in high-voltage environments.
• Versatile Installation Design Available in multiple configurations (e.g., wound-type, bar-type, bushing-type) to suit different cabinet layouts, busbar sizes, and installation space constraints.