FR 50 to 30 amp warning

Let me add some engineering clarity to this issue. StephenH has most of it right. Using the dogbone provides a single 120V/50A circuit. The 30A breaker in the camper will protect the wiring in the camper so the only thing left partially unprotected is the cord from the pedestal to the camper. If a true short were to develop in that cord or connectors, or the few feet of wire between the camper wall and the power converter panel inside the camper, the 50A breaker on the CG pedestal would trip. In the almost impossible situation where a cord defect could cause current of more than 30A but less than 50A to flow the cord would just get warm. Fire danger is essentially zero.

The use of a good surge protector that senses under and over voltage (TRC Surge Guard) is always recommended, even without a dogbone. Wiring errors or faulty wiring can cause a dangerous situation or equipment damage if undetected. Miswired pedestals can be hazardous to humans. Low voltage will damage A/C motors; high voltage will damage almost anything else plugged in to the camper. It’s very cheap insurance.