Low Frequency Transformers

Frequency Range: 50/60Hz

Single phase transformers
Power rating: 1VA to 20kVA

Three phase dry type transformers
Power rating: 100VA to 200 kVA

Low Frequency Transformer Lamination Selection Guide

The selection of the lamination type for a specific transformer depends on the design parameters and the designer’s personal preferences. The indicative power capacity for different lamination types (chart below) provides a general guideline for an initial selection.

Power Capacity by Lamination Type

Power range (W)	Imperial Type Laminations	Metric Type Laminations
<5	306, 212	EI28, EI35, EI41
5-10	212	EI41, EI48
10-20	212, 130, 120	EI48, EI54
20-50	120, 279, 43	EI54, EI57, EI66
50-100	279, 43, 174	EI66, EI76
100-200	174, 173	EI96, EI114
200-500	173, 180	EI114, EI133
500-1000	180, P	EI133, EI150
>1000	Q, S	EI171

Note: The power capacity of each lamination type varies due to differences in size, thickness, operating frequency and temperature, flux density, and material grade. Chart calculated using 50CS400 grade steel or equivalent laminations.

Imperial Lamination Range*

No. 306
No. 212
No. 130
No. 120
No. 279
No. 43
No. 174
No. 173
No. 180
No. P
No. 276
No. Q
No. S

Metric Lamination Range*

EI28
EI35
EI41
EI48
EI54
EI57
EI66
EI76
EI96
EI114
EI133
EI150
EI171

*These are the most commonly utilized laminations but it is not an exhaustive list or an equivalency chart. Should you require information on different laminations or grades of material, please contact one of our engineers for assistance.