shore power

Thanks everyone. I had a guy come out and check things out. He said that the pedestal was reading 250 volts. It looks like my surge protector is doing it's job. Ran on generator for two days with no problem. Checked the voltage here at a new campground and it is right on 240 volts. Hopefully things will be ok.

He said at "some campgrounds" meaning more than one. So unless he is just unlucky the problem is probably in the RV! That narrows the area somewhat. The surge protector that also monitor high/low voltage is a real possibility. Either he is unlucky again or it's the Power protection system. My 03 was a high end and it didn't even have a surge protector. I installed it in mine. If not that then I say again, it might be the shore side of the transfer switch. A bad relay could give intermittent indications. Remember there are two relays in the TS. One operates Genny power and one for shore power. The genny side works and the genny side is usually the default. OP, next time it happens you could also bang on the transfer switch box with your hand a few times. That may help...or may not! Good luck.

As myredracer suggested, it could be a low voltage problem on the park's pedestal. Your coach probably has a voltage transfer box that ignores voltage if it is too low. (My 1993 coach has that feature and I would assume yours would as well.)

There is no cheap, simple solution other than using a portable battery charger. (I've done that to keep my batteries up while I used the house battery bank as in dry camping.)

Possibility:

Check the voltage at the pedestal, then inside your MH before you turn things on and after plugging in a higher wattage appliance (hair dryer, etc.). If it plummets after turning on a high wattage item, it's the CG that's at fault and there's nothing you can do except for using an autoformer or the gen. You can try finding a site close to wherever a power transformer is located which may help.

If in an older park, the wiring is just too small for all the 50 amp RVs nowadays. It may look perfectly okay before plugging in, but if the wiring to the pedestal is too small, the voltage drop will too great and an EMS will trip. The NEC has changed a lot since the 60s when only 5% of park pedestals were required to be 50 amps. The latest NEC requires 20% to be 50 amps but that's still not enough for all the various RVs that have 50 amps now.

We were just at a Thousand Trails CG where the voltage was only 106 before we turned things on (we have 30 amp service). Wasn't long before our EMS tripped on low voltage. Tried another site and still no good. Then moved yet again to a section that had all 50 amp pedestals and it was fine.

I would check the output of the transfer switch when on shore power and everything is dead. If you don't have power than you probably have a bad shore power relay in the transfer switch. If you do have power there than probably a loose connection or the inverter.

Do you have a surge guard on your shore power input? If you are receiving low or high voltage or a spike, one of these will shut down the power.

Ron