Electrotechnical components Wound Cores

Strip wound cores for transformers and chokes Iskra, d. d. is one of the major Slovenian producers of various types of strip wound transformer cores made of oriented silicon iron steel strip. With our own production line and highly trained personnel, we fulfill the requirements of local and foreign markets. To produce high-quality cores for transformer and chokes, we use an oriented silicon iron steel strip that contains 3% silicon. We mainly produce cores from M103-27P and M089-27N materials. The strip thickness is 0.27 mm and can be used up to 200 Hz. The grain oriented silicon iron steel strip...

Dimensions • Toroidal cores are mostly used for power and instrument transformers, chokes and rotary transformers. • We offer cores with various dimensions: external diameter from 18 to 300 mm, in ternal diameter from 13 to 250 mm, h eight from 5 to 105 mm. • Cores are produced in accordance with the DIN 42311 standard customer request. • In order to achieve the best quality of cores, th e D/d=1.25 to 2 ratio must be established. The stacking factor n is the proportion between the effective magnetized average and geometrical average of the core.

The universal transformer equation V = — VRMS — VrmS - root mean square voltage Ap£ - core cross section area in m2 BpEAK - Peak magnetic flux density in T (tesla, Vs/m2) Hysteresis losses energy of hysteresis losses Empirical exponent varied from about 1.4 - 1.8 but is often given 1.6 for silicon iron core. Calculation of cross section area A - cross section area P - requested transformer power Insulations of toroidal cores The toroidal cores can be insulated with a Mylar foil 1 x 70 %, 2 x 2/3, etc or coated with epoxy resin. In some cases we put it in a plastic housing. All...

CM and CE cores CM and CE cores consist of four core halves (see drawing bellow). The coil former is on the middle leg. The transformer has horizontal or vertical holders. The horizontal holder and cores are wrapped with a clamp. Vertical holders of a core are fixed to the core with screws, washers and nuts. Cut cores are mostly used for power transformers, chokes and special transformers. C cores are distributed according to the standard; therefore they are listed under labels CM and CE cores. Electrotechnical components

CU cores CU cores consist of two core halves (see drawing bellow). The coil formers are on both legs. Horizontal holders are tight to cores by a clamp. Electrotechnical components

CG cores CG cores consist of four core halves (see drawing bellow). The coil formers are on both middle legs. There are horizontal and vertical holders. The horizontal holders are fixed to cores with one or two clamps. The vertical holders are fixed to the core by screws, washers and nuts. Electrotechnical components

C3U cores consist of two core halves (see drawing bellow). The coil formers are on all three legs. Horizontal holders are tight to cores by two clamps. Electrotechnical components

Appearant power of single phase core Appearant power of three phase core Type of GOESS materials

Toroidal cores • Rubberwasher •Tinned round plate CM, CE, CU, CG and C3U standard cores are provided with following accessories: • Clamps • Cartoon washer • Plastic coilformers • Vertical and horizontal holders

Remarks: . Asetofclamps consist of clamps, a bolt, a nut and a screw. • All Typeb cores are supplied with two sets of clamps.

Core with holder - CM102a Core with holder - CU60b Electrotechnical components

Accessories, Measurements Core with holder - C3U60a MDK1000A computer controlled measurement system The electromagnetic properties of cores are measured by an MDK1000A computer controlled measurement system. A BH curve, current and voltage shapes and their RMS values are displayed. The cores are measured in one, two or three points or by scanning. All parameters are memorized on a hard disk. The table below the diagrams shows electromagnetic values in numbers. A customer can get these results in a PDF form by E-mail. Electrotechnical components

Special cores Coated oval cores Toroidal cores with an air gap Electrotechnical components

Special cores Rectangular cores Toroidal cores with Mylar insulation Electrotechnical components

Published by Iskra, d. d. ■ Version 1.0, March 2013 Iskra, d.d. Stegne 21 SI-1000 Ljubljana Slovenia