Surge Guard 34850 High Voltage Shutdown

[Mongoose9400]

We are staying at a campground and continually losing power because our surge guard is sensing voltage greater than 132 V on one of the hot legs of the pedestal 50 amp supply.

Any idea what may causing the high voltage at the pedestal?
Surge Guard appears to reading a volt higher than my fluke meter.

Camp ground staff is blaming the surge guard and states their power is fine. Staff fluke meter measures voltage 2 volts lower than my fluke meter.

I just tried switching spots to what appeared to be a better site that measured lower voltage on a different circuit of the campground power grid, this didn’t seem to help either.

[bobbecky]

A couple questions:
You are seeing high voltage on one hotleg, but what is the voltage on the other hotleg at the same time you have the high voltage?

Where is your Surge Guard plugged in at?

It is very possible that, when there is no electric load, the voltage on both hotlegs is the same or very close, and once you put load on the shore cable, the voltage goes high on that hotleg. If this is happening on all the circuits in the park, it is likely that either in their system or in the utility system, there is an open neutral and this will cause this voltage imbalance because the neutral is not there to stabilize the hotlegs. Be thankful that your Surge Guard is working to keep your trailer safe. If needed, leave the park if they will not do anything about the problem. Most utilities are required to maintain service voltages within 5% above to 5% below the stated voltage, which in the USA is 120 volts on each hotleg, so no lower than 113 volts to 127 volts on the high end.

[Mongoose9400]

A couple questions:
You are seeing high voltage on one hotleg, but what is the voltage on the other hotleg at the same time you have the high voltage?

Where is your Surge Guard plugged in at?

It is very possible that, when there is no electric load, the voltage on both hotlegs is the same or very close, and once you put load on the shore cable, the voltage goes high on that hotleg. If this is happening on all the circuits in the park, it is likely that either in their system or in the utility system, there is an open neutral and this will cause this voltage imbalance because the neutral is not there to stabilize the hotlegs. Be thankful that your Surge Guard is working to keep your trailer safe. If needed, leave the park if they will not do anything about the problem. Most utilities are required to maintain service voltages within 5% above to 5% below the stated voltage, which in the USA is 120 volts on each hotleg, so no lower than 113 volts to 127 volts on the high end.

I’ve seen the high voltage shutdown caused by L1, L2 or Both L1 and L2 showing high voltage. The surge guard measure around 130 volts for each leg, with minimal difference between the legs, most of the time.

[flybouy]

I’ve seen the high voltage shutdown caused by L1, L2 or Both L1 and L2 showing high voltage. The surge guard measure around 130 volts for each leg, with minimal difference between the legs, most of the time.

Sounds like the cg needs to call the utility company.

[Javi]

I’ve seen the high voltage shutdown caused by L1, L2 or Both L1 and L2 showing high voltage. The surge guard measure around 130 volts for each leg, with minimal difference between the legs, most of the time.

If it were me, I'd ask them nicely to call the power company and if they refuse then; I'd find another campground and ask for a refund of any monies not used to date.

[sourdough]

The campground has a problem. As suggested above I would ask them to call the local utility provider and have it corrected immediately.

ANSI C84.1, American National Standard for Electric Power Systems and Equipment (60 Hertz) stipulates a variance of no more than 5% in the electrical power service. The power company will understand the importance of being in compliance with the NEC; the campground staff will probably not have a clue. The issue could be in either the primary power provider system (doubtful) or in the apparently self maintained campground power system (probably). Running that problem will probably take some time and money and they don't want to spend it. You might point out that the first trailer that loses its contents due to faulty power will cost far more than correcting the problem.

If they refuse to correct it I would A) make arrangements to move to another campground, B) advise them that you will make a formal complaint to the electrical provider then C) make that call.

[Customer1]

If the high voltage switches between L1 and L2 I would suspect a bad/intermittent neutral connection in the pedestal.

To test your SurgeGuard, use an adapter and plug into a 30a receptacle. The voltage should be identical on L1 and L2. If not, the pots need adjusted.

[LHaven]

I personally discovered that if a neutral on a campground circuit is insufficient (under-gauge, long run, or poor bus connection), someone drawing lots of current on one leg (V1) can bias the neutral voltage relative to their leg (e.g., 5% of V1 instead of 0), which raises the effective voltage of the other leg (e.g., 105% of V2) as the neutral is now biased away from zero. So this intermittent behavior could really be caused by any rig sharing the same breaker box as your site, as their AC cycles on, etc. The smoking gun is that the voltage on one leg goes down by the same amount that the voltage on the other goes up.