.. getting into VERY dangerous waters here, people.
The only way to know what a CB or fuse protects is to go back to the WDM or similar design document.
If the operational documentation provided to the crew does not specify the operational use of protection in abnormal or emergency situations, then the breakers ought not to be played with AT ALL .... in the great majority of cases, the pilot will have no real knowledge of what is hanging off the other end of the breaker and what consequential screwups might follow on from ill-considered tripping of breakers. What one learns in a pilot endorsement school about the mysteries under the trim covers usually is a very, very sanitised and simplified version of reality ...
Perhaps one of our electrical engineering design members might like to wade into the fray and emphasise the dangers to be encountered if one plays about with electricity ......