We have the Power Watchdog EPO 50A hard mounted in our 5th. Absolutely swear by it. It has “saved” us on one trip at a campground - open neutral. Plus the Bluetooth app on my phone, I can see each leg and the voltage being applied.
After plugging into the power pole and flipping the breaker on, in about 5 seconds, I hear a faint “thunk”, indicating that the power supply/pole all is good and power being sent to the RV. On the time when there was a neutral fault, after I didn’t hear the “thunk”, I looked at the Bluetooth app and it told me what the problem was and I notified the park mgmt. They came right out with the repair man and fixed the power pole and all was good.
This was just my one experience with a bad power pole, and all other travels haven’t had a problem, but, soooo thankful my new 5th was protected.