Reverse polarity

[bigb56]

There are a lot of RV surge protectors that are also circuit analyzers (all the ones I just looked at in fact). Depending on where the analyzer is located, what type it is and how compromised the neutral path is it might get fooled into showing reverse polarity instead of open neutral. The 3 light plug in testers are famous for that.

I am curious what your explanation as a tech is on what caused the reverse polarity reading?

 

[John From Detroit]

I don't know, the OP said it was a surge protector which is not the same as an EMS. Surge protectors don't stop power, they just absorb surges.

Many use the terms interchangablly.... Fact is teh EMS are in fact Surge protectors.. Surge protectors are no. (I know it sounds strange but Surge protectors are really Spike supressors)

All of the devices that I am familiar with open the power supply when an open neutral is present. What brands do not?

OPEN yes. Poor connection.. Wild card can detect wrong.

Mine (Surge Guard by TRC/Southwire Showed open ground when in fact it was poor neutral per the tec who fixed it. (park problem not mine)

 

[bigb56]

You have to look at how the test device determines what. It is not that smart. If the neutral is open with no current flow it can tell by comparing to ground, but if there is a load putting voltage on the neutral the test device isn't smart enough to tell you that, it will just show reverse polarity because it sees that voltage on the neutral and voltage on the neutral is how it determines reverse polarity.

I like what Mike Sokol said to me once when I told him the meter was lying, he said "the meter doesn't lie, we just don't always listen to what it is telling us"