E55/28/21-3C90

Transformer Cores, E, E55, 3C90, 124 mm, 353 mm²

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Manufacturer: FERROXCUBE
Product type: Transformer Cores
Core Type:E; Core Size:E55; Core Material Grade:3C90; For Use With:-; Effective Magnetic Path Length:124mm; Ae Effective Cross Section Area:353mm²; Inductance Factor Al:6.3µH; Product Range:-; SVHC
SVHC: No SVHC (17-Jan-2023)
Core Size: E55
Core Type: E
For Use With: -
Product Range: -
Core Material Grade: 3C90
Inductance Factor Al: 6.3µH
Effective Magnetic Path Length: 124mm
Ae Effective Cross Section Area: 353mm²

Delivery and price
Units per pack	600
Price	2.01 €
Current stock	500+
Lead time	30 days

Datasheet

_**FERROXCUBE**_ 

**E55/28/21** E cores and accessories Supersedes data of September 2004 2008 Sep 01 

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Ferroxcube 

## E cores and accessories 

## E55/28/21 

## **CORE SETS** 

## **Effective core parameters** 

|**SYMBOL**|**PARAMETER**|**VALUE**|**UNIT**|
|---|---|---|---|
|Σ(I/A)|core factor (C1)|0.350|mm−1|
|Ve|effective volume|44000|mm3|
|Ie|effective length|124|mm|
|Ae|effective area|353|mm2|
|Amin|minimum area|345|mm2|
|m|mass of core half|≈108|g|



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handbook, halfpage 56.2   −2.1 [0   ]<br>37.5  [+][1.5]<br>0<br>17.2   −0.5 [0   ]<br>R < 0.6 18.5  [+][0.8]<br>0    27.5<br>±0.3<br>R3<br>21.0   −0.8 [0   ]<br>CBW063<br>Dimensions in mm.<br>Fig.1  E55/28/21 core half.<br>**----- End of picture text -----**<br>


## **Core halves** 

AL measured in combination with a non-gapped core half, clamping force for AL measurements 40 ±20 N, unless stated otherwise. 

|otherwise.|||||
|---|---|---|---|---|
|**GRADE**|**AL**<br>**(nH)**|µ**e**|**TOTAL AIR GAP**<br>**(**µ**m)**|**TYPE NUMBER**|
|3C81|100±5%(1)|≈28|≈8740|E55/28/21-3C81-E100|
||160±5%(1)|≈45|≈4560|E55/28/21-3C81-E160|
||250±5%(1)|≈70|≈2500|E55/28/21-3C81-E250|
||315±5%(1)|≈88|≈1840|E55/28/21-3C81-E315|
||400±8%(1)|≈112|≈1360|E55/28/21-3C81-E400|
||630±10%(1)|≈176|≈780|E55/28/21-3C81-E630|
||8625±25%|≈2410|≈0|E55/28/21-3C81|
|3C90|100±5%(1)|≈28|≈8740|E55/28/21-3C90-E100|
||160±5%(1)|≈45|≈4560|E55/28/21-3C90-E160|
||250±5%(1)|≈70|≈2500|E55/28/21-3C90-E250|
||315±5%(1)|≈88|≈1840|E55/28/21-3C90-E315|
||400±8%(1)|≈112|≈1360|E55/28/21-3C90-E400|
||630±10%(1)|≈176|≈780|E55/28/21-3C90-E630|
||6300±25%|≈1760|≈0|E55/28/21-3C90|
|3C91|8625±25%|≈2410|≈0|E55/28/21-3C91|
|3C92|4700±25%|≈1310|≈0|E55/28/21-3C92|
|3C94|6400±25%|≈1790|≈0|E55/28/21-3C94|



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Ferroxcube 

## E cores and accessories 

## E55/28/21 

|**GRADE**|**AL**<br>**(nH)**|µ**e**|**TOTAL AIR GAP**<br>**(**µ**m)**|**TYPE NUMBER**|
|---|---|---|---|---|
|3C95|8625±25%|≈2410|≈0|E55/28/21-3C95|
|3F3|100±5%(1)|≈28|≈8740|E55/28/21-3F3-E100|
||160±5%(1)|≈45|≈4560|E55/28/21-3F3-E160|
||250±5%(1)|≈70|≈2500|E55/28/21-3F3-E250|
||315±5%(1)|≈88|≈1840|E55/28/21-3F3-E315|
||400±8%(1)|≈112|≈1360|E55/28/21-3F3-E400|
||630±10%(1)|≈176|≈780|E55/28/21-3F3-E630|
||5700±25%|≈1590|≈0|E55/28/21-3F3|



## **Note** 

1. Measured in combination with an equal gapped core half. 

## **Properties of core sets under power conditions** 

|**GRADE**|**B (mT) at**|**CORE LOSS (W) at**|**CORE LOSS (W) at**|**CORE LOSS (W) at**|**CORE LOSS (W) at**|**CORE LOSS (W) at**|
|---|---|---|---|---|---|---|
||**H = 250 A/m;**<br>**f = 25 kHz;**<br>**T = 100**°**C**|**f = 25 kHz;**<br>**= 200 mT;**<br>**T = 100**°**C**<br>**B**ˆ|**f = 100 kHz;**<br>**= 100 mT;**<br>**T = 100** °**C**<br>**B**ˆ|**f = 100 kHz;**<br>**= 200 mT;**<br>**T = 25**°**C**<br>**B**ˆ|**f = 100 kHz;**<br>**= 200 mT;**<br>**T = 100** °**C**<br>**B**ˆ|**f = 400 kHz;**<br>**= 50 mT;**<br>**T = 100**°**C**<br>**B**ˆ|
|3C81|≥320|≤9.0|−|−|−|−|
|3C90|≥320|≤4.8|≤5.9|−|−|−|
|3C91|≥320|−|≤3.5(1)|−|≤20(1)|−|
|3C92|≥370|−|≤3.8|−|≤27|−|
|3C94|≥320|−|≤3.8|−|≤27|−|
|3C95|≥320|−|−|≤27.7|≤26.4|−|
|3F3|≥320|−|≤5.6|−|−|≤10|



## **Note** 

1. Measured at 60 °C. 

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E cores and accessories 

## **COIL FORMERS** 

## **General data for E55/28/21 coil former without pins** 

|**PARAMETER**|**SPECIFICATION**|
|---|---|
|Coil former material|polyamide (PA6.6), glass reinforced, flame retardant in accordance with<br>_“UL 94-HB”_; UL file number E41613(M)|
|Maximum operatingtemperatur|e<br>130°C,_“IEC 60085”,_class B|



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3 ±0.1 2 ±0.1<br>(5×) (6×)<br>handbook, full pagewidth<br>5 ±0.1<br>21.7  [+][0.2] 0    [23.8   0   ] −0.2 [43.5   0   ] −0.2<br>20   −0.2 [0   ]<br>CBW064<br>1 ±0.1<br>17.6  [+][0.2] 0    33.2  [+][0.2] 0<br>24.2 ±0.2 35.7 ±0.1<br>37   −0.2 [0   ] 38.8 ±0.2<br>Dimensions in mm.<br>Fig.2  E55/28/21 coil former (E).<br>**----- End of picture text -----**<br>


## **Winding data and area product for E55/28/21 coil former without pins (E)** 

|**NUMBER OF**<br>**SECTIONS**|**MINIMUM**<br>**WINDING**<br>**AREA**<br>**(mm2)**|**MINIMUM**<br>**WINDING**<br>**WIDTH**<br>**(mm)**|**AVERAGE**<br>**LENGTH OF**<br>**TURN**<br>**(mm)**|**AREA**<br>**PRODUCT**<br>**Ae x Aw**<br>**(mm4)**|**TYPE NUMBER**|
|---|---|---|---|---|---|
|1|250|33.2|116|88250|CP-E55/28/21-1S|



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E cores and accessories 

## **General data for E55/28/21 coil former without pins (A)** 

|**PARAMETER**|**SPECIFICATION**|
|---|---|
|Coil former material|polyamide (PA6.6), glass reinforced, flame retardant in accordance with<br>_“UL 94-HB”_; UL file number E41938(M)|
|Maximum operatingtemperature|130°C,_“IEC 60085”,_class B|



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handbook, full pagewidth 36.6 37<br>19 33.7<br>16.9<br>42.15 21.1<br>max. min.<br>CBW065<br>Dimensions in mm.<br>Fig.3  E55/28/21 coil former (A).<br>**----- End of picture text -----**<br>


## **Winding data and area product for E55/28/21 coil former without pins (A)** 

|**NUMBER OF**<br>**SECTIONS**|**MINIMUM**<br>**WINDING**<br>**AREA**<br>**(mm2)**|**NOMINAL**<br>**WINDING**<br>**WIDTH**<br>**(mm)**|**AVERAGE**<br>**LENGTH OF**<br>**TURN**<br>**(mm)**|**AREA**<br>**PRODUCT**<br>**Ae x Aw**<br>**(mm4)**|**TYPE NUMBER**|
|---|---|---|---|---|---|
|1|277|33.7|113|97800|CP-E55/28/21-1S-A|



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Ferroxcube 

## E cores and accessories 

## E55/28/21 

## **General data for 14-pins E55/28/21 coil former** 

|**PARAMETER**|**SPECIFICATION**|
|---|---|
|Coil former material|polyamide (PA6.6), glass reinforced, flame retardant in accordance with<br>_“UL 94-HB”_; UL file number E41938(M)|
|Pin material|copper-zinc alloy(CuZn), tin (Sn) plated|
|Maximum operatingtemperature|105°C,_“IEC 60085”,_class A|
|Resistance to solderingheat|_“IEC 60068-2-20”_, Part 2, Test Tb, method 1B: 350°C, 3.5 s|
|Solderability|_“IEC 60068-2-20”_, Part 2, Test Ta, method 1: 235°C, 2 s|



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37.35 max.<br>handbook, full pagewidth<br>19.75 35.65 max.<br>17.45 min. 33<br>21.15<br>44.2  min. 23.7<br>max.<br>7.4<br>min.<br>5 0.4<br>1.15<br>40.15<br>CBW066 43.95 max.<br>4.3 min.<br>Dimensions in mm.<br>Fig.4  E55/28/21 coil former; 14-pins.<br>**----- End of picture text -----**<br>


**Winding data and area product for 14-pins E55/28/21 coil former** 

|**NUMBER OF**<br>**SECTIONS**|**MINIMUM**<br>**WINDING**<br>**AREA**<br>**(mm2)**|**NOMINAL**<br>**WINDING**<br>**WIDTH**<br>**(mm)**|**AVERAGE**<br>**LENGTH OF**<br>**TURN**<br>**(mm)**|**AREA**<br>**PRODUCT**<br>**Ae x Aw**<br>**(mm4)**|**TYPE NUMBER**|
|---|---|---|---|---|---|
|1|278|33|119|98100|CPH-E55/28/21-1S-14P-Z|



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Ferroxcube 

## E cores and accessories 

## E55/28/21 

## **MOUNTING PARTS** 

## **GENERAL DATA FOR MOUNTING PARTS** 

|**ITEM**|**REMARKS**|**FIGURE**|**TYPE NUMBER**|
|---|---|---|---|
|Clasp|steel, zinc (Zn) plated|5|CLA-E55/28/21|
|Spring|steel, zinc (Zn) plated|6|SPR-E55/28/21|



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58.8 max.<br>handbook, full pagewidth<br>35 23.5 21 27.94<br>2.8<br>50.8 CBW495<br>44<br>4<br>∅9<br>65.3 max.<br>Dimensions in mm.<br>Fig.5  E55/28/21 clasp.<br>**----- End of picture text -----**<br>


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6.8  [+][0.5]<br>handbook, full pagewidth 0<br>0.2<br>21 ±0.2<br>min.<br>60.2 ±0.2 46 56.1<br>CBW068<br>4.2 24.3<br>Dimensions in mm.<br>Fig.6  E55/28/21 spring.<br>**----- End of picture text -----**<br>


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E cores and accessories 

## **DATA SHEET STATUS DEFINITIONS** 

|**DATA SHEET**<br>**STATUS**|**PRODUCT**<br>**STATUS**|**DEFINITIONS**|
|---|---|---|
|Preliminary<br>specification|Development|This data sheet contains preliminary data. Ferroxcube reserves the right to<br>make changes at any time without notice in order to improve design and<br>supplythe best possible product.|
|Product specification|Production|This data sheet contains final specifications. Ferroxcube reserves the right<br>to make changes at any time without notice in order to improve design and<br>supplythe best possible product.|



## **DISCLAIMER** 

 **Life support applications** These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Ferroxcube customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Ferroxcube for any damages resulting from such application. 

## **PRODUCT STATUS DEFINITIONS** 

|**STATUS**|**INDICATION**|**DEFINITION**|
|---|---|---|
|**Prototype**||These are products that have been made as development samples for the purposes of<br>technical evaluation only. The data for these types is provisional and is subject to<br>change.|
|**Design-in**||These products are recommended for new designs.|
|**Preferred**||These products are recommended for use in current designs and are available via our<br>sales channels.|
|**Support**||These products are**not**recommended for new designs and may not be available<br>through all of our sales channels. Customers are advised to check for availability.|



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Updated at April 28, 2026

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