AC Power drops for 2 - 3 seconds then comes back on

[StoryOnTheRoad.com]

I have a 2020 Solitude 375 RES-R. Every day using both air conditioners, we will get a sudden AC power disconnect for about 2-3 seconds and then the power will come back. This has happened at 3 different campgrounds. I had installed a Victron Multiplus 2000 inverter to charge Battle Born lithium batteries and run the residential frig and some outlets. Also installed a BMV 712 to monitor 12V usage. Originally I had the Victron wired through an AM Solar Smart Phase Selector. I double checked the wiring diagram to make sure I didn't make a mistake there and everything was okay. Thinking it might be bad, I disconnected it and ran one leg of the entrance wiring directly to the main panel and connected the other leg through the Victron and out to the other side of the 50amp breaker in the main panel. Still have the power drop using both air conditioners and no other items other than a couple of small drain 115 outlets. No big load anywhere. The Victron only shows about 13 - 15 amps going through it. I was using a Hughes Autoformer at the pole. So I replaced it with a Progressive Surge Protector thinking it might be that. Still no change. What am I missing. I am monitoring the Victron from Bluetooth and it is showing 50 amp pass through. I can't figure out where we could be getting a hit. Would an air conditioner cause something like this? When it happens the back air conditioner is running. I can't say if the one in the bedroom is running. We have them on auto.

Wayne Story
2020 Solitude 375 RES-R
2017 Ford F-350 Lariat Dually

[howson]

Power drops on BOTH of the incoming 120vAC legs for 2-3 seconds? The entire trailer loses 120vAC?

[TucsonJim]

Do you have an electrical management system? Either portable or hard wired?

Jim

[StoryOnTheRoad.com]

Yes, the entire trailer looses power just momentarily. Then comes back on. No breakers are triggered. The post breaker is not triggered.

TucsonJim, I'm not sure what you mean by an "electrical management system", if you mean at the power campground power pedestal, I had a Hughes Autoformer and then replaced with a Progressive Surge Protector.

[StoryOnTheRoad.com]

When it goes, both air conditioners go off and of course will not come back on because the thermostats go to off. Everything else works after its automatic reset. But I cant figure out what could be causing the automatic reset. Other than the Victron Inverter, there is nothing in the AC line coming to the house breaker panel box.

Wayne

[howson]

When it goes, both air conditioners go off and of course will not come back on because the thermostats go to off. Everything else works after its automatic reset. But I cant figure out what could be causing the automatic reset. Other than the Victron Inverter, there is nothing in the AC line coming to the house breaker panel box.

Wayne

The thermostats work off of 12vDC. Do they go blank when the air conditioners turn off? Do you lose all the lights, too?

[howson]

By "lights" I mean the overhead LED lights in the living area, bathroom, bedroom--any and all of the lighting in the camper (they are all 12v LEDs).

[StoryOnTheRoad.com]

Howson, I can't say for sure about the 12v system. This almost always happens in the afternoons when the ACs are going. It is off such a short time that I don't have time to get up and check anything. That's what is so puzzling. It will also happen when we leave for the afternoon and comeback and the ACs are off. We have been here several times when it happens and if we are watching the TV, it will go off with the rest of 115 circuits and then we can turn it right back on. The thermostats on the air conditioners reset to off when it happens.

[howson]

Howson, I can't say for sure about the 12v system. This almost always happens in the afternoons when the ACs are going. It is off such a short time that I don't have time to get up and check anything. That's what is so puzzling. It will also happen when we leave for the afternoon and comeback and the ACs are off. We have been here several times when it happens and if we are watching the TV, it will go off with the rest of 115 circuits and then we can turn it right back on. The thermostats on the air conditioners reset to off when it happens.

You have Coleman air conditioners, right? I don't think the thermostats will reset to OFF with a loss of AC power. I'm headed out to my camper right now to do a test...be right back.

[howson]

StoryOnTheRoad.com ,
Yep--the problem is in the 12vDC side of your camper, not the 120vAC.

The system in my camper is far from OEM, so I first turned off my inverter and solar, completely disabling those components. They were not on so had no effect on these tests. I did not turn off shore power so the AMSolar device (I have it, too) didn't change or affect anything, either.

I turned on the living room Coleman 15K air conditioner and verified the compressor was running. I then shut off the main 50A circuit breakers on the Power Distribution Panel, killing all 120vAC. The thermostat stayed active and set on COOL HIGH. When I turned the AC breakers back on the Coleman started running again.

I repeated this test but instead of turning off the main 50A 120vAC breakers I switched off DC power. Within a moment the air conditioners were off and (predictably) the thermostats were blank. When I restored 12vDC the display showed OFF.

[TucsonJim]

Yes, the entire trailer looses power just momentarily. Then comes back on. No breakers are triggered. The post breaker is not triggered.

TucsonJim, I'm not sure what you mean by an "electrical management system", if you mean at the power campground power pedestal, I had a Hughes Autoformer and then replaced with a Progressive Surge Protector.

An EMS such as from Progressive Industries shuts down power if the incoming electrical current has an issue. I have one and it will frequently shut down the rig if I'm parked in an RV park with lots of people running their AC in the afternoon. When too many people are drawing from the RV park grid, they may cause a low voltage condition which your EMS would shut down the power in order to protect your electrical equipment including your air conditioners.

But unless you paid to have one installed, it won't have one. And if you had the Hughes autoformer running at the time the power went out, it's not likely that you'd have seen a low voltage situation anyway.


JIm

[StoryOnTheRoad.com]

Howson, I will check the 12 v system. It runs through the brand new Victron inverter to two 100 amp hour Lithium batteries from Battleborn. Why would the 12 v system cause the 115 AC system to reset also? We hear the other electrical systems like the microwave reset. Both of the Coleman air conditioners shut down when this happens. What in the 12 v system do you think could cause this.
Wayne

[StoryOnTheRoad.com]

Jim, I don't think it is a campground voltage problem. I'm watching the Bluetooth app on the Victron and it seems to show a steady 119 - 121 v ac. We have been to 3 different campground two with few people in them and the same thing happens. I have been using the Hughes Autoformer to handle the lower voltages.
Wayne

[howson]

Howson, I will check the 12 v system. It runs through the brand new Victron inverter to two 100 amp hour Lithium batteries from Battleborn. Why would the 12 v system cause the 115 AC system to reset also? We hear the other electrical systems like the microwave reset. Both of the Coleman air conditioners shut down when this happens. What in the 12 v system do you think could cause this.
Wayne

When the Victron loses 12vDC, it also turns itself off. When that happens any 120vAC being passed from shore power through the Victron also stops. (Easy to test--with shore power ON, turn the Victron OFF. What stops working in the camper?) For me it is everything on leg 1 ("L1" in the picture below) as L1's 120vAC passes through the inverter. Inverter off--no 120vAC on that leg (even with shore power connected).

Make sense?

Why is the 12vDC system dropping offline? Total conjecture on my part, but it sounds like the Battery Management System ("BMS") inside one or both of the Battle Borns are sensing a problem and are turning themselves off. After a second or two they no longer sense the issue and turn back on. But that is a (semi-educated) guess.

It could just as easily be a loose ground wire issue. On my 315RLTS there was a gaggle of grounds tied together with a wire nut near the front "A" frame. I rewired by adding lugs and then attaching all of them to a lug post. Jim ( TucsonJim that posted earlier) went even further and put his grounds on a lug bar (and did a fantastic job).

[StoryOnTheRoad.com]

Thank you Howson, I will go through the ground wires and check.