Outback Inverter Tripping

Tess

I have a new offgrid solar system. I created a 48 volt battery bank using 4 each, 100Ah, LiFePO4 Battle Born batteries wired in serial. I'm using an Midnight Solar epanel stretch for Outback equipment. The epanel uses a 175 Amp battery shut off for inverter (MNEDC175) for my configuration of Outback VFXR3648A Inverter/charger and FX80 Charge Controller. My battery bank is 9ft from epanel with 2/0 cable. In the middle of the 9 ft run I have wired a 48v battery switch which honestly doesn't appear very sturdy. 
My Charge Controller functions fine, displays about 53v for the battery bank and all the connections up to the 175 amp battery shut off are testing at 48 volts nominally. The Charge Controller will continue to function normally until I turn on the 175 Amp switch opening the connection to the inverter. Then everything goes dark. I can turn back on the Charge Controller again and it will function normally again until I switch back on the Inverter. The inverter during these tests has no loads. It doesn't appear the inverter stays on long enough to register errors in my Mate 3s.
Also, this shutoff of the inverter and subsequently the charge controller happens whether the PV array is on and feeding the charge controller or not.
I have replaced the battery switch for the battery on the positive battery connection and upgraded the bus bar for the negative to a stronger bus bar in the battery shut off box.
My other concern is a pre-wired battery positive connection with lower ampacity rating from the input to the 175 amp inverter switch that feeds the battery positive to the charge controller but that is functioning fine as long as the inverter switch is set to off. The 175 amp inverter switch is specified for my configuration.
Can someone provide some input on what I might try to isolate the issue? ... or have other suggestions?
I can provide the image of the epanel if that is acceptable here. I'm very frustrated with Outback's caliber of support. They took weeks to answer a simple, previous question. 

wellbuilt

I’m no expert but I have the same equipment  ,  
 First I would   Isolate the inverter  You could power up just the inverter and see if it works , then add components AC out see if it inverts . 
  I had a  problem with a double ground that would pop my inverter breaker , I believe there was a green ground wire in the inverter that need to be moved so there was only one common ground . It’s under the top cover 

wellbuilt

I have a flex power one system out back 36 48 there  is a quick start guide the shows the wiring clearly maybe this could help . 
 

Photowhit

Something  isn't right.   I admit to not understanding/following your description of the wiring.  Photos are always welcome.

I did a couple diagrams of my E-panel wiring for another forum, so someone could understand the flow;


This is the path into the E-Panel and out to the Charge controllers(2 arrays);
+ is red
- is blue/gray


I was showing the path from incoming from the array, so it shows arrows out to the battery, but of course it's DC current and the energy will go where needed. The inverter draws from the system. 

Also this is a photo while I was wiring the system, There is no AC breaker yet or Neutral - Ground bond.

mcgivor

Just a thought, when an inverter is initially turned on the capacitors demand a high momentary current which may overwhelm the battery's internal BMS. You may want to ask Battleborne, they seem very willing to help, a 3.6Kv inverter is not small in comparison to the limited battery capacity, the initial inrush may, or may not be the cause of the problem.

Estragon

Does the epanel have GFP breakers on the pv input?

mike95490

I'll take "Initial Inrush" !

To test that theory, wire a high power light bulb (like a +100w halogen bulb) and place that across the switch, or area you are making that final 48VDC connection.  The bulb will limit inrush amps till the caps charge up, and when the bulb dims down and goes out, you can make the final connection and then remove the bulb & it's wire.   If it was Inrush, and still works, the bulb did the trick.

If the system faults again, time to keep digging.  I'd start at the 9 foot long 48VDC run,

Estragon

It could be inrush, but would that pull Vbatt low enough for long enough for the CC to shut down (and apparently not log an error)?  

IIRC, the FX does a POST (power on self test) for several seconds before normal operations begin.  Do the leds on the unit flash and fan test run before it shuts down?

When swapping boards on one of mine a few years ago, it seems to me I tested it on the bench using some dry cell lantern batteries in series, and it got through the POST process with just those forpower.