High Quality Customized Nanocrystalline Square Magnetic Cutting Core

Product Definition

A nanocrystalline square magnetic cutting core is a magnetic core manufactured from nanocrystalline alloy ribbon and supplied in a square (rectangular) geometry with a cut or split in one limb. The cut design allows the core to be opened and installed around a pre-assembled conductor or busbar without disconnecting the circuit, which is a decisive advantage in retrofits, metering installations and maintenance work.

The core is produced by winding nanocrystalline ribbon, annealing it in a magnetic field to develop the nanocrystalline structure, and then cutting the finished core with ground mating faces to control the air gap.

Key Properties

High permeability: typical initial permeability above 80,000, which improves current transformer accuracy and linearity while reducing core volume.

Low core loss: significantly lower hysteresis and eddy current losses than ferrite and conventional silicon steel at medium and high frequencies.

High saturation flux density: approximately 1.2 T, allowing the core to handle strong magnetic fields without saturation.

Wide operating temperature range: reliable operation from -55 C to 120 C.

Cut (split) design: the core can be opened and closed for installation around existing conductors.

Customizable dimensions: outside diameter, inside diameter, height and length can be manufactured to specific requirements.

Available Dimensions

Custom sizes are available on request. The effective permeability of a cut core depends on the air gap length, which is controlled during grinding.

Applications

Current transformers: high accuracy and linearity for metering and protection.

Power transformers and audio transformers: low loss at mains frequency and in audio output stages.

Inductors and chokes: boost PFC chokes and smoothing inductors in power supplies.

EMI filters: common-mode and differential-mode filtering in inverters and drives.

Inductive absorbers: high-frequency noise absorption in inverter-fed motor systems.

Selection Points

Choose the window (ID) size to fit the conductor or busbar with the required creepage and clearance.

Specify the air gap and effective permeability for the target inductance and DC bias.

Confirm the operating frequency to select the correct ribbon thickness and alloy grade.

For current transformers, specify the accuracy class and burden in line with IEC 61869-2.

FAQ

Q: Why choose a cutting core instead of a closed toroid?
A: A cutting core can be opened and mounted around existing cables or busbars, avoiding circuit disconnection during installation.

Q: Does the cut reduce performance?
A: The air gap reduces the effective permeability slightly, but it also improves linearity and DC bias tolerance, which is often beneficial for current transformers and chokes.

Q: What temperature range can these cores withstand?
A: Typically -55 C to 120 C for standard grades.

Q: Can the dimensions be customized?
A: Yes, OD, ID, height and length can be produced to customer drawings within manufacturing limits.

Q: What standards apply to current transformers using these cores?
A: IEC 61869-1 and IEC 61869-2 define the accuracy, insulation and test requirements.