Park Voltage changes with load (50) amp version

[ralph0808]

If the current on both legs is about the same the voltage is usually very close also. But if no load on L1 and L2 has the usual 5-7 amps then AC & water heater turn on L1 then L1 may go down to 111 volts 25 amp a L2 then may be 127 or 128 volts 5 amp and the inverter flashes a warning or it just shut down because voltage is too high.

[DrDaveMA]

Originally Posted by ralph0808

Ok guys I still the problem and I think it is inside the RV somewhere!! I have the grounding rod installed and it made no difference. I then returned to the water heater which was part of the problem. The dealership Service Manager told me 1/06/15 when I purchased it that he personally changed the electric element, and it was a 2000 watt on a 15 amp circuit. I put a 1500 watt element in today because of high current loading on leg L1. But the voltage swing continues with one going high 127-129 volts while the other maybe 111-115 or even down to 109. So I have crawled around inside the beast and checked every screw for every wire in the hard wired TRC 40250-RVC surge guard. I have checked the connections for the inverter, the main panel, sub panel, checked the power cord and cleaned the pins on the plug. The surge guard was replaced in 4/15 at a different dealership under extended warranties. So I don't know what to check next. I have the PT50 plugged in at pedestal saying E-0 and giving the same voltages that I have with digital meters and also two DVM that are usually within a volt or two difference. So what's next??

Ralph, in post #16 you said you had moved to another site and did not have the problem, why do you think it now on your coach?

[nothermark]

What you need to look for is where the voltage drops. If you are measuring about the same at the plug and at any internal point then your RV wiring is not the problem.

If the park voltage is out of balance that indicates more load in the park on one leg vs the other. Not a problem for you in the sense that it won't hurt anything as long as you are within the 120 +- 10% range. If the voltage at the post is stable but the loss shown in the RV start measuring voltage at points in between.

[ralph0808]

Well guys this evening I have completely bypassed the TRC Surge guard and went from power cord to the main panel with the EMS PT50 plugged in the park pedestal. Guess what? Still have the problem. I had also dismantled the power cord automatic reel looking for a junction box or slip rings but the power cord goes straight to the surge guard which I had bypassed for this test. The voltage goes up or down depending on which leg has the highest load. So I put the system all back together and did the test with the generator again and this time the DW took photos of the steady voltage up 45 amps on L1 and 15 amps L2 with a both a steady 120 volts give or take volt with changes in loads. So I had to convince myself again that from the Onan every thing was just fine. My male power plug could be the problem, but it doesn't show any kind of stress or burning or arch and I cleaned the brass pins. I have the classic Bad Neutral problem and I will have move across town on my next day off to try a different power source.

[DrDaveMA]

Can you move the EMS PT50 to another site and another coach? Maybe the entire park has the problem?

[ralph0808]

Dave, I am thinking the same thing. But I need to check with Progressive Industries and see if the PT50 should indicate a bad or floating neutral!!

[DrDaveMA]

About the only code is E-2 open ground, but they should be able to help you interpret the results you are seeing.

[ralph0808]

Ok guys, we once again ran a source of power from another pedestal over to the RV with same results. I was getting very tired of this! So we packed up moved to another park owned by same company and got the same results. Yep I was fed up! So I disconnected the power cord, went bought a 25 ft 50 amps extension cord and it wasn't long enough so borrowed a cord with a bad male plug and replaced the plug and wired directly to the surge guard using the extension cord and borrowed cord and still had the same results of bad or weak Neutral. Maintenance man is confident that the problem is in my RV, so I take the same cord setup and go to my main panel in hallway and connect directly to my breakers and Neutral buss & ground buss. Measure the voltage before even turning on my breaker and get L1-124v & L2-119 without any loading at all. So turn on breaker and L2 has the inverter load of about 6.5 amps 117v and L1 goes up to 126v and 0 amps. So I am completely convinced that the problem is not in my RV. I may even convinced the maintenance man! We will see if and when we get the cable ran back at our pad for the season!

[wolfe10]

124/119 on the two legs is quite possible and not necessarily a problem.

If, say there are 20 sites on that CG power supply circuit, if more people are running things on L2 (50 amp) or L2 supplies more 30 amp outlets that are in use, that variance is explainable.

Again, 108- 132 is acceptable (120 plus/minus `10%).

[ralph0808]

Ok guys, this is what we did today. We packed up once again and moved to a different location in the same park that had a new 50 amp service just completed 2 years ago. The meter base was only about 30 feet away from pedestal. Anyway I measured the voltage on each leg and to neutral and also to ground. It looked good and I put the PT50 in the socket and it showed good power E-0 L1 121v 0 amps L2 121v 0 amps. I had my hopes up but the DW wasn't as hopeful. So anyway we plugged the RV in and started checking the system out. We loaded it down on each leg separately and both legs at the same time. We have finally found a good source of 50 amp 240 volt power. The legs only varied by a volt or two when a load was applied to that specific Leg which was to be expected, not like before the opposite Leg would go up to 127 or 128 and other leg would go down to 110 or 109. So I have finally convinced park management that the Host site at the other park needs new power wire ran, capable of handling 50 amps on each leg with a good solid neutral and ground. It is a relief to have a good source of power. Thanks for your help and discussion of my power problems that were not in my RV.

[DrDaveMA]

Ralph, glad to hear you got it worked out. I have found the Progressive Industries products are rarely not right.