What types of bus couplers exist?
A bus coupler is just a normal circuit breaker (and isolators), no matter where it's installed, or which busses it's connecting.

A "cross bus coupler" is just a bus coupler that happens to be connecting the two busses of a double-bus switchyard. It's not a different type of switchgear and shouldn't be classified as such.



Similar terms are:


Bus tie
Bus section (circuit breaker) - in switchboards