What distinguishes a two bushing transformer from a CSP transformer?

A two bushing transformer is distinct from a CSP (Competitively Sourced Power) transformer primarily due to its lack of internal fusing. This characteristic allows the two bushing transformer to function at a different level of complexity and design compared to CSP transformers, which typically incorporate various safety features, including internal fuses to protect against faults.

The absence of internal fusing in a two bushing transformer indicates that external protection devices, like circuit breakers or relays, are relied upon to manage electrical faults, which can affect the overall safety and operational protocols in a distribution system. This design choice often leads to a more straightforward construction and can influence maintenance practices. The other options, such as the number of bushings, size, and efficiency, do not accurately highlight the defining differences in operational functionality related to fusing and protection design.