Campground Electrical - Reverse Polarity?

[phil-t]

OK, we are camphosts at this State Park. Today, and occasionally in the past two years, some folks have complained about reverse polarity readings on there surge protectors. These sites all have a 30A and a 20A GFCI in the pedestal. I take my circuit tester (the cheapy lights one from Lowes) and it shows no reverse polarity - additionally when I test with my digital Fluke multimeter there is no reverse polarity. Tester routinely shows 118V between ground and hot or neutral and hot; 0 volts (maybe 5 miliA) between neutral and ground.
Does this individual have a weird or failed surge protector? I don't have record of what make the surge protector is.
Park Rangers typically offer a refund on the site with a one night stay.

 

[Domo]

Is it always the same site(s) or same loops that goes to a common distribution panel.

Does anyone have an alternate surge protector that could be plugged in when the camper reports their protector shows a reverse?

As a host I know you want to help - but going much further is probably beyond the job description the same as for the rangers that just give a refund (should move them to another site and get a real electrician).

There are real test meters for 50, 30 and 15 amp outlets (you'd need all three) perhaps if the state is loosing a few nights income a week they might buy them for the hosts to use as tools (that you don't get to keep!). And/or is could become part of the site cleanup task to verify power when the site is inspected to avoid having to move frustrated campers or lose income?

Perhaps some folks have found out how to get a free night's stay?

 

[phil-t]

Not the same sites or the same distribution panel. And others that plug in there do not see an issue. I'm just thinking there is an issue with their surge protector but don't see a way to prove that. I assume the tests we are performing are adequate - maybe not if there is some other issue with the campground electrical.
I have absolutely no issue with my power (in a site, in the same campground, served from the same distribution panel, using a Huges Autoformer.

 

[SpencerPJ]

Tough spot, you say all is good, it's not, it comes full circle. I'd send them on there way and ask the Campground Park folks how they want it answered.

 

[phil-t]

That's where they are! Offered a refund.

 

[John From Detroit]

It is possible there is a 'Weak" Ground. They can "Fool" a Energy Monitor/Surge Guard.

 

[phil-t]

I'm wondering if the surge protector is especially sensitive to the ~5miliV on the neutral?

 

[Kirk]

Not the same sites or the same distribution panel. And others that plug in there do not see an issue. I'm just thinking there is an issue with their surge protector but don't see a way to prove that.

Have you ever moved the customer to a different site to see if the same thing happens? That is what I'd do if I were the host at that park. I also have always used a full line protection device such as those from Progressive or Southwire so would probably have tested with mine. If the customer has one that is something more than just surge protection, look to see what the error shown is as most of them do have at least some indications.

It is possible there is a 'Weak" Ground. They can "Fool" a Energy Monitor/Surge Guard.

I'd be interested to know about what a "weak ground" is? In my 40 years of electrical service work I don't remember running into that sort of issue.

 

[Wasillaguy]

I'd be interested to know about what a "weak ground" is?

Had a gov engineer once tell me he suspected a high impedance short circuit.

 

[John From Detroit]

Have you ever moved the customer to a different site to see if the same thing happens? That is what I'd do if I were the host at that park. I also have always used a full line protection device such as those from Progressive or Southwire so would probably have tested with mine. If the customer has one that is something more than just surge protection, look to see what the error shown is as most of them do have at least some indications.

I'd be interested to know about what a "weak ground" is? In my 40 years of electrical service work I don't remember running into that sort of issue.

Would you prefer "High Impedance" Rusty Screw.. Screw not tight. poor connection. instead of "Weak Ground". what I'm talking about is any thing puts voltage on the ground pin.

 

[Gary RV_Wizard]

Is their "surge protector" a plug-in type, or hard-wired at the RV power cord connection? Depending on how their device determines "reverse polarity", it's conceivable there is an intermittent connection problem in their shore cord or rig and it's fooling their device. That's more likely if the shore cord is between the pedestal and a hard-wired surge device (more places something could go wrong).

I'm guessing here because we don't know what device is in use, but most any measurable voltage (more than afew volts) between neutral and ground would probably result in a reverse polarity diagnostic.

 

[phil-t]

I don't know the make of the customer's device. It is a portable, looks like a "cheapie", not a Huges, or Surgeguard, or Progressive or Southwire.
It has the same issue at multiple sites, different distribution panels, etc. He is, now, plugged in all night and today without issue. No site work has been done except for testing. He leaves tomorrow, I will check all connections in the pedestal but assume I will find no problems.
Gary - I think that is a good question - how does his device determine a reverse polarity issue?

 

[CharlesinGA]

I would have one of these simple testers

and one of these puck adapters.

And I only suggest the puck adapter as it is compact and easy to store with the tester.

Take those to the campsite and test the 15/20 amp GFCI receptacle, and the 30 amp receptacle and say, "see, tester is not showing any reverse polarity" or, "yep, you are right, its reversed"

Charles

 

[phil-t]

That's exactly what I did. First thing.

 

[Kirk]

how does his device determine a reverse polarity issue?

Reversed polarity on a 30A or a 15A outlet means that the slot that should be 120V is neutral and the slot that should be neutral is 120V.

 

[phil-t]

I understand that.

 

[Kirk]

I understand that.

Then it simply checks to see which pin has the voltage and will not engage if not proper. If you want the electronics involved that is a little more complicated.

 

[Gary RV_Wizard]

I think we get that, Kirk, and phil-t has already done the simple checks to verify with his meter and outlet tester.

Since the neutral isn't always exactly zero volts relative to ground, the device has to have some threshold value for voltage between the alleged neutral and the ground. It's possible there is some voltage variance in the campground system that occasionally exceeds whatever the device thinks is OK. We also do not know if the device checks polarity only once (when power comes on) or continuously. I thought most such devices did polarity only once and relied on voltage peak monitoring the rest of the time, but again we don't know what this one does. And probably never will know.

 

[phil-t]

That's what I was trying to figure out. In the future, I will get make model of the devices that are reporting the reverse polarity and try to do some research.
The customer vacated this AM and I checked all terminations in the site pedestal and the distribution panel. No problems found there.

 

[Gary RV_Wizard]

Few of the surge protect devices tell how they make their checks, so knowing what brand it is may not help much.