A transformer that includes built-in overload and lightning protection is referred to as what?

The term "Completely Self Protected" for a transformer signifies that the device has been designed with integrated mechanisms to prevent damage from both overloads and lightning strikes. This type of transformer includes internal features such as fuses or circuit breakers that can disconnect the transformer in the event of an overload condition, as well as surge protection to mitigate the effects of lightning.

These protective features are crucial for enhancing the reliability and longevity of the transformer while also ensuring safety in electrical systems. By having these protections built in, the need for external protective devices is reduced, simplifying installation and maintenance for utility companies.

This distinguishing characteristic of being fully equipped with internal protections justifies the designation of "Completely Self Protected." Other names might not capture the full range of protection features as effectively, which is why they do not align as closely with the standard industry terminology.