Vbus Over Range, but No PV

Come on! Someone has to have some idea why this inverter would say this despite having no PV input?

I have seen a few threads on here and other places regarding this.  The typical culprit is often either a grounding issue someplace, needing a firmware update, or there was one that ended up being a multifunction printer (believe or not, that was with a 6000xp I believe).

It seems you have narrowed it down to the Eaton 3kVA UPS.

I would suggest calling your supplier or using the contact for on the EG4 site and work with a tech directly on this.

But a few things you might chase out.

You mentioned that having something else on tends to mitigate the problem.

Is that other load generally on the other leg of the 240 than the UPS or the dryer?

I have read a few vague references to leg imbalance issues where if one leg is significantly higher than the other leg it can cause problems.  I have not investigated it all but just read about it in passing.

On something like this though I would really suggest reaching out to the EG4 techs using this link:

EG4 Technical Support - EG4 Electronics

Sorry I wasn't any help and maybe someone else will chime in.

JB

I made a separate post about how I solved this, but it is apparently stuck in moderation hell, so maybe I can get the word out here. This problem seems to be caused by non-linear loads with poor power factor. Some hair dryers use half-wave rectification to get a low power setting and this drives the inverter crazy. My UPS has a bad power factor to similar result. Another poster here was having a problem with a laser printer in his parents' camper and I verified a similar result with a laser printer.

Since power factor seems to be the culprit, power factor correction seems to be the answer. I experimented with some motor run capacitors that I had on hand and found that I could get a stable result with my UPS with 50 uF. I need 160 uF to get the inverter to stay online with a hair dryer and the UPS. And with 240 uF the inverter will handle anything I throw at it. So my solution is to get large electrical enclosure and put the capacitors in it, protected by a 30 amp breaker.

With 240 uF of capacitance, about 21 amps flows. But the cool thing is, this is purely reactive current and doesn't represent any real power. The inverter doesn't even register it on the screen. In other words, even though 21 amps is flowing through the capacitor wires, almost no power is being drawn from my batteries. I will experiment with adding some resistors in series to reduce the current and see if it still allows those pesky loads to operate fault free. But for now, I'll live with the 21 amps.

Maybe EG4 will send me a free battery or two for solving this problem😁