How much is "too much"?

[DutchmenSport]

Question for the electrical experts (a little background first).

I'm camped at a state historic site in Louisiana (3 years in a row here now, come and go, and return again for months at a time).

I'm on a 50 amp RV electric hook up and for the last 2 - 3 years or so, have had no issues. I have a portable 50 amp Progressive EMS at the pole which has been working great for years now.

A few nights ago, the EMS shut the trailer down. The volts skyrocketed, Line 1 - 140 volts, and line 2 to 141 volts.

I switched over to my 30 amp Hughes Autofoamer and plugged the camper into the 30 amp outlet and reverted back to old school (30 amp power management). It worked out OK, considering the outside temperature dropped here in Louisiana and there was no need to run 2 air conditioners at the same time.

Meanwhile, I kept the 50 amp Progressive plugged in (but not plugged to the trailer). For several days I'd flip on the power and check the volts, and every day it came down slightly, and today the Progressive 50 amp, the service is showing line 1 - 125 volts, line 2 - 125 volts. BUT ... no more error codes.

I decided to switch power and plugged the camper into the 50 amp side again and the camper is running normal, and the Progressive is still showing both legs 125 and no errors.

But, my concern is, ... how high is too high? Is 125 acceptable? I'm not sure how high the volt spikes get before the Progressive shuts down the camper. What I find strange is, my progressive has been showing between 115 and 120 for at least 2 years now, and then all of a sudden a spike to 140 and then it's taken days for it to come back down to 125.

I talked to the park management, and they have someone scheduled to come out, but hey ... this is not a conventional campground, and I'm the only camper here (I'm not very high on the priority list).

I'm trusting the Progressive 50 amp EMS to protect me on this one. It's turning hot again, running both AC's is a must. All things OK, for the moment, yes. But just wondering ... how high is too high?

 

[foldbak]

I wish I was smart enough to answer, thank goodness for AI

125 volts is on the high side, but it is generally considered acceptable and within the safe operating range for most RV appliances.
The standard "sweet spot" for North American power is 120V. Most RV electrical components and EMS devices use a +/- 10% rule of thumb.

The Danger Zones:

• Safe Range: 108V to 132V.
• The "Yellow" Zone: 126V to 130V. Your electronics might run a bit hot, and incandescent bulbs will burn out faster, but it won't immediate destroy anything.
• The Shutdown Point: Most Progressive Dynamics EMS units are programmed to trip and cut power once the voltage hits 132V or higher.

Why did it hit 140V+?
A spike to 140V is a major red flag. Since you are the only one there and it took days to "settle," it sounds like a floating or loose neutral in the park's transformer or the pedestal itself. In a 50-amp service (which is actually two 120V legs), if the neutral connection fails, the voltage can "swing." One leg drops low while the other skyrockets toward 240V. This is likely why your EMS saved your rig from a total meltdown.

Verdict:
You are safe at 125V, but that 140V event proves the park's infrastructure has a physical fault. Transformers don't just "calm down" over several days on their own; it’s possible the temperature change affected a loose wire or the utility company adjusted something on their end.
Keep that EMS plugged in—it’s the only thing that stood between you and a very expensive repair bill.

 

[DutchmenSport]

Thank-you Mikendebbie.
No assistance yet from the park, but recruitment will come... eventually.

FYI, The EMS is still showing 125 on both legs this morning.

Thank-you again.

 

[Mikendebbie]

…that info was from Mr Foldbak - not me! I gave him a LIKE for great information!

 

[DutchmenSport]

Ah, Thank you foldbak.

FYI... no electrician from the park yet. Power still holding at 125 (both legs) so using the 50 amp outlet. 4:30 am (today), power went out. Progressive shut down again. I checked and it spiked again to 134 and 137. I plugged back into the 30 amp outlet with the autofoamer again. Checked the 50 amp side (6:30 am) and it's now showing 139 - 141.

It's gonna get hot today. I may just end up breaking out my generators to run both AC's later today if help doesn't come soon! I love the solitude at the park, being the only camper here. But isolation has disadvantages (sometimes) also.

By the way, I'm doing an all day 1820 style carpentry demonstration today. I'll be dressing out in character!

 

[jkxtreme]

First thing is check the voltage with a quality volt meter. The 10% rule is pretty standard so 132 volts is the high limit. I have operated at 135 volts on each leg, but that is higher than I like. All that said, when you plug into a 50 amp service, your will normally see 220 - 240 volts between the hot legs, so the wire insulation on your appliances and systems should handle 140 volts. The issue will be the increased amperage consumed by the devices that are resistive based. (space heaters, electric fireplaces, etc ). Also keep in mind the converter that changes the AC power to DC for charging your batteries and powering the lights could be an issue. If that DC voltage goes too high, you could harm the lighting and charging circuit. Stay within that 10% limit to be sure you won't have a problem. In industry I have seen voltages increase like that when there was either very little load or no load on the system. Once the system was loaded the voltage came down to acceptable limits. It sound slike the poer company has changed the taps on their transformer or they replaced a local transformer and set the taps incorrectly. The campground should call the power company to see if the changed something.

 

[DutchmenSport]

Follow-up report....

The surges have continued. The power company was called to confirm (or deny) any problems from the electric company to the parks electric meter. No issues there.

More spikes, more switching back to the 30 amp side, weather getting warmer.

State Parks electrician came out just a bit earlier today. After numerous conversations, numerous opinions, and even the idea that my Progressive EMS may be the entire problem, the guy who came out today finally found the issue.

The issue IS at the power pole. The socket the breaker itself sits in is screwed down keeping all the connections tight. Well guess what? The screws holding the connection tight are stripped out! Yea!

Everyone agreed the problem was a "neutral" problem causing the ill behavior. But no one wanted to actually open the pole panel off and actually look at the 50 amp breaker. This guy did! And he saw the problem immediately! Imagine!

Well, things move a little slower in Louisiana and considering this is not a "normal" campground situation, the guy is going to do what he has to do to get a brand new camper panel (20, 30, 50 amp sockets). Now we wait a bit longer to get the equipment.

If this were a conventional state park, the park's maintenance shop most likely would have extra shore power breaker boxes for the campground. Not being a campground, no such thing exists here. Red-tape, requests, approvals acquisitions, and then finally getting someone to do the work.

Problem solved, but wait again.