The core type is used for high-voltage applications like autotransformers and power transformers. Shell type is used for low-voltage applications like transformers in an electronic circuit. Cooling is better in core type, because the windings are directly exposed to the atmosphere, as compared to shell type ones.
A type of transformer in which the magnetic circuit consists of one central limb and two outer limbs, and both primary and secondary windings are placed on the central limb is called a shell-type transformer. The core makes 3 limbs.
In shell-type transformers, a shorter magnetic path is available, hence it requires a small magnetizing current. Natural cooling is poor in shell-type transformers because the coils are placed on the central limb. The shell-type transformers are mainly used in low voltage and high output applications.
It gives better support against electromagnetic forces between the current-carrying transformer. More flux can be flown through the core.
A shell-type transformer consists of two magnetic circuits. A core-type transformer has concentric winding (or cylindrical winding). A shell-type transformer has sandwich winding (or interleaved winding or disc winding).
A type of transformer in which the magnetic circuit consists of two vertical sections called limbs and two horizontal sections called yokes and the windings placed on the limbs is called core type transformer. In a core type transformer, the windings surround the core of transformer. A core type transformer consists of two limbs and two yokes. The core type transformers are used for high voltage and high-power transformers.
A shell-type transformer is commonly used as it has two magnetic paths and reduced magnetic flux leakage.
The losses in a core type transformer are more as compared to shell type transformer because the core type transformer consists of two magnetic circuits. In core type transformer few windings are removed for maintenance. In shell type transformer numbers of the winding are required to remove for the maintenance.