high voltage at outlets

[ojo123]

Just came back from the MOC gathering in Quartzsite and plugged into the power pedestal at the park and after setting up most of the trailer noticed we had 220 volts at the outlets... not good. I disconnected from the pedestal and removed the surge protector and plugged back in and all was fine. Reinstalled the surge protector and all is fine.. Can anyone give me a clue as how one can get 220 volts at all the outlets. It fried something on the AC that was runnning as a heat pump. No longer produces heat or cold. Clues anyone on how this can happen?

[Bourbon County]

That's a classic symptom of an open or high impedance neutral. Most of the surge protectors are supposed to catch that condition; and it's troubling that it cleared after unplugging and plugging back in.

Fortunately, there aren't many places that can occur. If you do have a solid neutral at the pedestal, that leaves the male and female plugs on your shore power cord, the inlet plug on your RV, and the breaker panel itself. There is a very remote possibility it's in the cord itself or the cable between the inlet plug and breaker panel, but the odds of cord damage that just cut through the neutral wire and only that wire are very unlikely.

The troubleshooting for this condition is highly dependent on your comfort level working around electricity and skills using a multi meter.

[rohrmann]

You might check the plug on the shore cord for a broken neutral prong. That would explain why it was fixed after you unplugged and reinstalled the plug of the cord. Also, surge protectors won't necessarily protect your rig from voltage at 240 volts, but an EMS will, as it will also protect from an open neutral as well as a missing or open ground. If any of these conditions are in the shore cord, the plug-in EMS will not protect but installing the hardwired version will.

[BB_TX]

I agree with the open neutral theory. Unplugging and replugging points toward a loose or poor wire connection. The movements in plugging and unplugging would cause movements in the wiring and possibly cause the poor connection to reestablish. At least temporarily.

In this case it would point to 1. The trailer power cord plug, 2. the surge protector outlet, 3. the surge protector power cord plug, 4. the shore power outlet. Each of those should be opened up and checked for secure wire connections.

This is not to say it may not be somewhere in the source power path. As an additional precaution I would check the shore power connector on the rear of the trailer. There have been numerous cases of poorly connected wires there. Handling the power cord could also have caused enough movement in that connector to cause loose wiring to move.

[BB_TX]

Did you solve the problem? When you do please let us know. It helps us all help others, and ourselves, in the future with similar issues.