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amosnandy · 04-13-2021, 08:04 AM

Brief description. (well not so brief) While parked this winter with a 50 amp hookup, I was watching tv and suddenly lost all 110 volt power to all of my outlets. Anything that ran directly from the 50 amp breaker panel still worked. Heat/AC, water heater, engine heater, battery charger, etc. Anything that ran through the 30 amp subpanel was dead. Which is basically just the 110 outlets, including the microwave. So I pulled the faceplate off both the 50 main distribution panel and the 30 amp sub panel. Got the VOM out and started checking voltages. Everything in the main had correct voltage, but nothing was being fed to the 30 amp sub. I checked the 30 amp breaker in the main, that feed the 30 amp sub and voltage was fine. I then started checking the power to the power management board that is in the 50 amp distribution panel. It appeared it was being fed by the 30 amp breaker in the main, but was not putting anything out to the sub. So I switched to the ohms and started checking what fed the sub. Figured out which wire went directly to the 30 amp sub panel and CAREFULLY put a 12 gauge jumper wire to the sub panel. One at a time I flipped the breakers on for the various 110 lines. Each worked. So I came to the conclusion somehow the power management system failed. I left it like that for a day, being careful not to draw more than 15 amps on the jumper. When I got ready to travel, I took the jumper off, so as not to have anything change going down the road. Well all the outlets now worked, without the jumper, but the inverter was showing it shut off due to overload. I powered everything down and looked up the reset procedure, (press the invertor button 3 times) and checked the 30 amp breaker on the invertor but no 110 invertor power. The only thing I had ever used this for going down the road was to run the refrigerator on 110 to save LP. It showed a draw of 450 watts. But I still have no power from the invertor. Anybody have any suggestions before I start ripping into the invertor? Anyway to tell if it is a failure of some kind in the PMS or if it is in the invertor? The charge function on the invertor charger still works fine. I do know from doing some checking before that turning the house batteries off at the dash does not shut the 12v to the invertor off. Short of disconnecting the battery cables is there a way to shut off the power from house batteries from the invertor? IF you got this far and have some answers, thanks. I know its a long post. I've been around these things all my life and I hate posts that you have to go digging for answers from the guy who is asking for help.

okcnewbie · 04-13-2021, 08:16 AM

Not sure but; If you connect to 50amp and AC units and other things work I would think that power management is working.
This sounds like inverter to me. I would disconnect the batteries for a few minutes and then hook them back up. Verify you have a 12-15 volts going to inverter and then get out the manual for the inverter. My inverter has two separate branches and we blow one of them regularly even when plugged into 50 amp service. I think I have a schematic for the power man. system somewhere if you need it but I'm thinking inverter

SKP Kirk · 04-13-2021, 02:28 PM

Because I don't completely understand what you posted, I would have to be there with my meter to give much by way of suggestions, but I will be interested to see what you come up with.

tomgrigsby · 04-13-2021, 05:09 PM

I had a similar issue, lost all outlets. The inverter passes 110 shore power to outlets. Had a melted wire nut under the inverter cover on the output black wire

amosnandy · 04-14-2021, 08:00 AM

Quote:

Originally Posted by okcnewbie

Not sure but; If you connect to 50amp and AC units and other things work I would think that power management is working.
This sounds like inverter to me. I would disconnect the batteries for a few minutes and then hook them back up. Verify you have a 12-15 volts going to inverter and then get out the manual for the inverter. My inverter has two separate branches and we blow one of them regularly even when plugged into 50 amp service. I think I have a schematic for the power man. system somewhere if you need it but I'm thinking inverter

That's what I am thinking. Because while all the outlets went dead, the power to anything that runs off the 50 amp main was still working. I'm thinking with only a 2000 watt inverter it only feeds stuff on the 30 amp sub panel. I do know that when you switch off the house 12v from the switch on the dash 12V still goes to the invertor. So yeah, I will try and disconnect the batteries to see if the invertor resets. I know it is getting 110v because the charger works as normal and it must be feeding the house batteries and the coach batteries because all that works. Voltages are fine. Also I have not really checked the PMS on 30 amp. In Mexico we only have 30 amp so I used it all winter. I did mooch dock at my cousins for a couple days, with a 15 amp cord, but I never try and run anything but the tv and fridge, and keep the batteries charged. The indicator on the PMS was working correctly showing a draw between 2 and 8 amps.