Progressive EMS 30

[JohnF]

I'm currently camping at a private campground in NC with room for about 15 campers. After midnight my Progressive senses voltage increases and cuts my power off until about 6 a.m. It trys throughout this time to turn power back on but quickly turns it back off. The unit is telling me it is a high voltage problem. There are currently only 2 rv's camping here. I'm getting through the night fine with my 12 volt systems and I have run a heavy extension cord directly from the pedestal into the camper. I use it for my portable electric heater and my coffee pot. I want to tell management about the problem but want to help them resolve the issue as well. What is happening with their setup that is causing my issues?

[youroo]

I bet Herk will bring the Hughes Autoformer into this Post! Youroo!!

[Mr Havercamp]

How high is it? I believe the EMS 30 cuts it at 132 volts.

I'd tell them. It could be an issue with the neutral in the campgrounds system, do they have single pedestals for 2 campsites by chance?

More than likely its something on the power companies end, that's why you see it at night when the load on the overall grid decreases.

[elundquist]

The power spike could be due to power company or a bad/ weak neutral.


Given there is only two RVs using the camp I would suspect the neutral. In particular with the use of electrical heat.

To make it simple let's say both sites are using ether 20A and/ or 30A connections. With a 120/240 VAC service you have two hot lines/ legs. On a 20A or 30A connection you are only using one of those line/ legs.

On a single circuit the power comes in the hot line/ leg through the load and returns to the power source (load panel) through the neutral.

In a good design they would have every other site wired to the opposite hot line/ legs to balance the loads.

Now at the distribution point (load panel) the circuits are tied together on the neutrals. At some point (typically at the service entrance or transformer) the neutrals are grounded.
This is because A/C does not require a complete return path to the generation source.

Now each hot line/ leg is at 120VAC and out of phase with each other. If you connect a single load to both hot line/ legs you get 240VAC.

What might be happening is the neutral at load center back to the service entrance has a bad connection.

The power from two sites wired to each leg travel from there respective load back to the load center on there respective neutrals. If the neutral bus at the load center has a poor/ weak connection to the service neutral it allows the voltage rise on both circuits on the neutral side.

Same thing could happen on a camper with a 50A service and a bad neutral connection. On the camper the problem would be in between the converter and the pedestal. The camper example should not effect other camp sites.

Finding the bad neutral might be quickly found by looking at the connections with a thermal camera or inferred thermometer. The bad connection should be generating heat.

They should examine the neutral connection starting at the two pedestals currently in use and work back to the service entrance.


Erik Lundquist
iPhone 6S using Tapatalk

[JohnF]

Voltage goes up to 135 at night

[Witch Doctor]

Originally Posted by JohnF

Voltage goes up to 135 at night

I would be telling the CG owner this problem, they are more then likely going to have the power company come out. Your voltage as you found out should not fluctuate that much at all. His electrical company should be able to tell him who's problem it is. Lucky you have EMS on your line. You would really be helping him in the long run...Good Luck

[elundquist]

I would bet the site pedestals are feed with aluminum wiring and those connections at the pedestals have not been checked or tighten since installed. The pedestals typically have a feed/ loop bar that allows the pedestals to be daisy chained. If somewhere in the daisy chain the neutral lug is not tight it could offer enough resistance to allow the voltage to rise durning low loads. If the two current campers are only running electric heating after midnight that would present the low constant load.

Durning a higher load the current is enough to overcome the resistance of the pour connection.

It very possible it could just be the connection in that one pedestal to the feed/ loop bar.


One could investigate the problem using a voltage meter when the problem occurs. Start at the one pedestal known to have the problem and check the voltage at one of the outlets. Then check each adjacent pedestal, and working outward to the ends of the line of sites. If you know the direction of the power feed you can just work backwards.

Checking the voltage, at the time of the problem, at an outlet in the park's facilities building would tell you if it's a common utility voltage problem, as the sites are typically a different service from the buildings.

It is possible for utilities to have power spikes, even up to 132V, but its extremely rare for them to occur consistently each night and/or for 6 hours! They are typically random and very short in duration < 1 minute; if not for a few seconds.




Erik Lundquist
iPhone 6S using Tapatalk