Core type transformer and shell type transformer are the types of transformer based on construction differences. In this article, we will see the difference between core and shell type transformer based on the iron requirement, conducting material requirement, leakage flux, maintenance, natural cooling, types of winding usage, applications, etc.
Let us see the difference between the two in detail.
Difference Between Core and Shell type transformer in tabular form
The differences between core type transformer and shell type transformer are given as below.
| Core type Transformer | Shell type transformer |
| Core type transformer requires less iron. | Shell type transformer requires more iron. |
| Core type transformer requires more conducting material. | Shell type transformer requires less conducting material. |
| Core type transformer is used in low flux density applications. | Shell type transformer is used in high flux density applications. |
| Core type transformer is economical for high voltage applications (since more space for insulation). | Shell type transformer is not economical for high voltage applications. |
| Winding surrounds the core in Core type transformer. | The core surrounds the winding in Shell type transformer. |
| For single-phase transformers, it has a two-legged core. | For single-phase transformers, it has a three-legged core. |
| Winding installed in both legs of the core. | Windings installed in the mid-leg of the core. |
| There is only one path of the magnetic circuit. | There are two paths of the magnetic circuit. |
| Core type transformer has maximum leakage flux. Hence more losses. | Shell type transformer has minimum leakage flux. Hence fewer losses. |
| Maintenance of this type of transformer is simple. | The maintenance of this type of transformer is complex. |
| We cannot provide natural cooling for this type of transformer. | We can provide natural cooling for this type of transformer. |
| In this type of transformer, concentric cylindrical winding is used. | In this type of transformer, the sandwiched winding is used. |
Conclusion
Core type transformer uses concentric cylindrical winding whereas the shell type transformer uses sandwiched winding. It is also noted that in a core type transformer, winding surrounds the core whereas, in a shell type transformer, the core surrounds the winding. The requirement of iron is less in core type transformer as compared to shell type transformer. Core type transformer is used in low flux density applications whereas shell type transformer is used in high flux density applications. Core type transformer is economical for high voltage applications whereas shell type transformer is not economical for high voltage applications.
