The basic types of transformers are three-phase and single-phase.
Three-phase 7-wire transformers, three-phase 3-winding transformers, and transformers for both motive and illumination power are examples of transformers that obtain power and electric light from a single unit.
Replacing two transformers, one three-phase and one single-phase, with one transformer saves space.

Transformers for both motive and illumination power are transformers that can simultaneously supply power to a three-phase load (power) and a single-phase load x1 circuit (electric light).

Transformers need to be selected according to the primary-side power receiving environment and the secondary-side load conditions, as well as the wiring and number of phases.

For details, please refer to the video.

2023.2.3：FAQ What is transformer for both motive and illumination power for low-voltage power receiving and distribution?