With regard to installation, these devices may be identified as:
- Cast resin dry type, conventional dry type or oil immersed
- With air core or gapped iron core
- With or without magnetic shield
- With or without enclosure
- For indoor or outdoor installation
Therefore, the location of the phase windings and their position relative to operating personnel, other apparatus and metallic structures must be well planned so as to minimise exposure, undue heating and dangerous forces during the period of short time current.