50 amp electrical issue

[TXiceman]

I have a strange issue going on with the power. I have a 50 amp RV with a Progressive Industries EMS and also a Hughes Auto Transformer when needed.

As long as the campground does not have many campers (this is on the 30 amp loop, but we have "50 amp" service), we do OK to a point and I have to use the Auto Transformer so that we can run the heat pumps or A/C. We are southwest of Houston, so we get really mixed weather.

Now the problem. Without the Auto Transformer, L1 will drop voltage as low as 104 volts which shuts down the EMS. When L1 leg goes low, L2 goes high to about 127 volts with no or a very small load on L2. The EMS drops the trailer off line with L1 low voltage.

If I put the Auto Transformer on line, L1 will drop with a 20 amp load and it will boost the voltage on L1 to keep the voltage up. Then L2 will go high and the EMS will take the trailer off line on high voltage on L2.

With no or 3 or 4 amp load, both legs will read 121 volts. Add some load and the voltage drops like a rock. I had the park check the pedestal and everything is OK there. I checked all of the connections in the RV and all is tight.

The park flooded twice last year and the electrical was under water for 2 or 3 weeks. They closed the park and pulled the guts in all of the panels and replaced them after the water went down.

I am at a loss to solve the problem and the park is no help. We are hosting here until the end of March but maybe forced to leave early if they can not get us dependable power. The trailer has a 22 cubic foot residential refrigerator, washer drier, dishwasher and two heat pumps. All appliances are pulling normal amps when at voltage.

Any ideas to pass along would be appreciated.

Ken

[time2roll]

TXiceman wrote:
this is on the 30 amp loop, but we have "50 amp" service

What does this mean? Is the pedestal 30a? I assume autoformer, EMS and RV are 50 amp.

Or as host do you have 50a and the rest are 30?

There is only L1 with 30a service so the L1 vs L2 seems confusing unless that is just your RV.
Are you using adapters?

Otherwise yes whenever voltage climbs it is pointing to a bad neutral.

Could check voltages at all boxes in the loop to possibly determine where the issue starts. Or you may end up back at the main panel.

[TXiceman]

Jerry, that is my thinking since they do not know the condition from the flood. They do not have any way to high pot test the wiring. Trying to get the state park to get an electrician out to check it.

Ken

[Mandalay_Parr]

Sounds like it might be an underground problem with the neutral.