Utility transformer

[hillbilly1]

Transformers have some OCPD.
Some like a CSP transformer have a secondary breaker that trips just like the one in your house.
Look below. The switch with the hole for a long stick is connected to the secondary breaker.
View attachment 2573761

Others like the picture MD Automation posted have fuses and are conventional transformers with two bushings on the primary.

Here is a chart that substantiates what Elect117 posted.
View attachment 2573762

Ours has a switch kinda like that, but it is for changing the voltage. They doubled our line voltage, so they changed all the transformers to dual volt, then killed the main line, switched it to the higher voltage, then while it was still dead, went to all the poles and flipped the switch. That minimized the down time for the customers.

 

[Hv&Lv]

Ours has a switch kinda like that, but it is for changing the voltage. They doubled our line voltage, so they changed all the transformers to dual volt, then killed the main line, switched it to the higher voltage, then while it was still dead, went to all the poles and flipped the switch. That minimized the down time for the customers.

They have CSPs with breakers AND tap changers.
75%of ours are dual voltage