Reverse Polarity Warning with Surge Guard 44260

[sixthscroll]

I’m at an RV resort. I was using the 30A outlier, and when I plugged my Surge Guard model 44260 in, it showed good (3 green lights).

When I plugged the RV in, breaker open, still good.

When I closed the breaker, I got a reverse polarity light (top left turned red).

When I tried to identify what was causing it by closing all the individual breakers one at a time, the AC and the microwave cause the reverse polarity to occur independently.

When the process was repeated on the 50A outlet, no reverse polarity.

Is it me and my rig? Or is the park at fault and needs to know?

Thoughts?

[creativepart]

I did Google search on your issue and found this:

https://gdrvowners.com/forum/operati...3431#post23431

[sixthscroll]

Thanks. I also figured out that if I leave the thermostat off during hookup and then turn it on, everything is green.

Weird.

[bigb]

Originally Posted by creativepart

I did Google search on your issue and found this:

https://gdrvowners.com/forum/operati...3431#post23431

That is a good explanation, but there is also the possibility of a compromised neutral connection which I am kind of surprised they didn't mention. They did mention undersized wiring, which a compromised neutral connection could mimic under heavy loading. When the neutral connection has a problem causing abnormal resistance there will be a rise in potential (to ground) on the neutral which can fool the tester into indicating a reverse polarity condition since all the tester does is monitor for voltage between ground & neutral, which under ideal conditions should be zero or close to zero. So this could have been as simple as a poor connection in the pedestal at the receptacle neutral blade or the screw terminal.

A way to better understand this is by plugging a 3 light tester into a circuit with an open neutral and a downstream load connected. The tester will indicate a reverse polarity condition, because the current is flowing down to the load, thru the load and back up the neutral but since the neutral is open it can't return to the source and the potential to ground rises and illuminates the reverse polarity light on the tester.

I have seen this when a switched receptacle is (incorrectly) switched by the neutral. Plug in a lamp, plug in a 3 light tester to the other half. Tester shows all good. Switch the wall switch off with lamp still on, tester now shows reverse polarity.

[powercat_ras]

Good discussion of how RVs get power and ground connections.

ABC's of RV Power Distribution: Part 1 by Mike Sokol

ABC's of RV Power Distribution: Part 2 by Mike Sokol

RV Electricity Mike Sokol Web Site