Shore power with only 30 and 15 amp in pole?

[virginiacamper]

Hi, we have a new (to us) XL with a magnum inverter/converter and 6 house batteries. All works great when plugged into 50 amp or running the generator, but given we are traveling in areas with only 30 and 15 in the pole we were hoping to use one of the cable systems where it allows us to plug the 50 cable into a 30 and 15. When we tried it our coach power protector (progressive) shows both legs at correct voltage and all ok, but the magnum will not charge or pass the power into the rig.

I am guessing the turn on voltage drops at first which shuts the magnum down. I do see many class As plugged into 30 and would have thought I could as long as the draw stays low (running a fridge and a few lights). Am I missing anything or is this just the way it works in the world of 50amp inverter/converters?

PS - because of the above we have been running our generator once or twice a day and people have complained since we are in a powered space. We use the 15 amp to run an extension cord for a fan, but keep the batteries for just the fridge and sone lights. I also have the magnum remote and have checked all of the settings. The only one that I thought could impact this is maxshoreamps which I turned down with no apparent effect. Appreciate any help as I can't be the first running into this for sure.


Thanks!