Softmagnetic Core Material | MRC Rolls

MRC Rolls for suppressing harmful interference currents, especially in use in radiated areas

New devices must be checked in accordance with the EMC directive before they can be introduced in a country of the European Union.

Electromagnetic interferences with frequencies of up to about 30 MHz tend to be conducted via cables and current paths or to be coupled between cables via inductive / capacitive mechanisms. Interference signals above 30 MHz, on the other hand, are emitted by metallic parts, components or cables that act as antennas.

In EU generally recognized frequency ranges for conducted and radiated interference:

Frequency Range (kHz)

These interferences can be suppressed or attenuated in various ways to restore compatibility with valid EMC directives (2014/30/EU).

Conducted Interferences

Power line interference and noise from switch mode power supplies are major sources of conducted EMC interference. AC power lines are the most important channel through which conducted electromagnetic interference can enter or exit equipment.

See also MRC Leaflets on Filter Cores, CMC and SoftProtector Cores:

Radiated Interferences

Shielding prevents emitted interference signals from entering or leaving a housing. Developers can use various shielding mechanisms. 

If EMC problems are only discovered later in a running project (unshielded cables have been chosen for reasons of cost or selected shielding approaches prove to be impractical) a quick and convenient solution of absorbing radiated interference is required.

MRC Components GmbH & Co. KG offers nanocrystalline rolls which suppress HF interferences and contribute to replace the expensive shielding of motor cables, easy to retrofit, to keep the required EMC limits. These rolls can be used inside housings as well as outside. They are simply attached over L1 + L2 + L3 lines (without N and PE) and absorb the harmful RF noise before it is emitted. This releases a small amount of heat that is simply dissipated to the environment. These absorbers can currently be used in engines up to approx. 1 MW.

List for the Rolls (LF):

Power range (kW) Roll Ref. Nom. Dimensions [mm] max. cased dimensions [mm] Lfe
ca. lsat (Apk)
7 - 22 MRC10821 30 x 20 x 100 35 x 15 x 140 7,8 3,9 9
30 - 45 MRC10822 50 x 40 x 200 58 x 35 x 240 14,13 7,8 16
55 - 90 MRC10823 80 x 60 x 300 88 x 55 x350 21,9 23,4 26
110 - 800 MRC10824 160 x 130 x 300 170 x 122 x 360 45,5 35,1 54

The information is non-binding and can be adjusted without prior information. No liability is assumend.

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Important note: For safety and the proper usage, you are requested to approve the offered product specification for your application. These products are designed for general electronic
devices. Performance and safety of this product for applications which could lead to physical harm is not confirmed. Be sure to examine the performance and safety when the product is used
for these applications and take appropriate measures, such as failsafe, to avoid any accident. It is the responsibility of user to take such measures.