Question I Blew a 250A Fuse at the Battery After an Upgrade, Looking for Help

[annotat3r]

Hello All,

This spring I put in the effort to upgrade the power configuration in my 2020 Starcraft Autumn Ridge 182RB 23' travel trailer. I upgraded my 65 amp-hour lead-acid battery to a 100Ah LiFePO4, and I replaced my converter with a 2000W Charging Inverter as previously there was no inverter installed. I also added some solar panels to prolong usage while off-grid, as my wife and I primarily boondock camp. I consider myself fairly competent with both AC and DC power systems so I felt good about tackling this project by myself.

For reference to my question, I have attached 2 PDF files showing the wiring diagram of my systems pre and post project.

Say what you will regarding Chinese products, but I selected the SungoldPower 2000W 12V Pure Sine Wave Inverter with Charger as my charging inverter over a name-brand unit such as Victron or similar. After having done a fair amount of research, these sungoldpower units are well reviewed and the $650 price I paid fit into my budget better than the $1,400 price for a Multi-Plus or similar.

The basics of my project were, remove the old lead-acid battery and replace that with the new Lithium Iron Phosphate battery. The new battery then connects to the charging inverter through a 250A fuse using 00 gauge wire, which then connects to the 12V DC Fuse panel. Previously, the lead acid battery connected directly to the fuse panel.
Remove the factory converter, which was not compatible with LiFePO4 batteries.
On the AC side, the shore power now connects to the AC input side of the Charging Inverter (previously shore power connected directly to the AC Breaker Panel). The AC Output side of the Charging Inverter is then connected to the AC Breaker Panel.
Add a Victron 100V 30A solar charge controller and solar panels.

After all of this work was completed, everything works as intended. 12V DC inverts to 120V AC when shore power gets disconnected. Shore Power charges the new battery. All Solar functions work. AC outlets and appliances work as expected both off shore power and while the inverter is doing its thing, and no problems on the DC side of things.

My only issue is when I am connected to shore power and the inverter is in bypass mode (not inverting DC to AC) and I flip on the Air Conditioner unit, I torched the 250A fuse connected between the charging inverter and the battery on the DC side. I'm having trouble understanding what would be happening that turning on the AC would attempt to draw any amperage from the battery at all if I'm connected to shore power, let alone draw enough amps to blow a 250A fuse. If the charging inverter is in bypass mode, the AC shore power should literally be just passing through the charging inverter to the load, not trying to draw from the battery, correct?
Needless to say, I have a lot of questions on why this would be happening but rather than sit and speculate and sink a ton of money into trying to troubleshoot, I wanted to see if anyone could offer some sound advice on the subject. For reference, my AC unit is a Dometic 13,500 BTU rooftop unit. AC worked and ran fine before this power upgrade.

I would really appreciate any thoughts on this.
-Ryan

 

[Kevin D Pem]

You have a lot of information to digest!!!

Because there is a dip switch setting for frequency, make sure it is set for 60hz.

Make sure the line/common connections are correct for in and out as they seem to be inverted. (AC)

Make sure the delay switch allows for a dip in frequency if your using a generator. A sag due to the extra load may trigger the inverter.

Last but not by any means least, because the manual on the inverter shows a transfer switch, your inverter may be trying to supply the grid if it has a slightly higher frequency than the grid.

It is difficult to answer what the programmers algorithm was to handle variations.

 

[annotat3r]

You have a lot of information to digest!!!

Because there is a dip switch setting for frequency, make sure it is set for 60hz.

Make sure the line/common connections are correct for in and out as they seem to be inverted. (AC)

Make sure the delay switch allows for a dip in frequency if your using a generator. A sag due to the extra load may trigger the inverter.

Last but not by any means least, because the manual on the inverter shows a transfer switch, your inverter may be trying to supply the grid if it has a slightly higher frequency than the grid.

It is difficult to answer what the programmers algorithm was to handle variations.

Hi Kevin,

Yes, the DIP switch is properly set to 60hz.
What makes you believe that the line/common connections are inverted?
I am not using a generator.
The inverter has a digital display which indicates the frequency of the inverter output when in inverter mode, and indicates the AC line in frequency when on shore power. First, the inverter should not be in inverter mode while plugged into shore power, it should be in bypass mode, where the line in simply passes through the device and the input hertz is equal to the output hertz. When in inverter mode, there is no grid to supply. Either way, the indicated AC frequency is 60Hz plus/minus 1Hz.

 

[Kevin D Pem]

The legend on the manual shows (l ) (c) (c) (l) as I recall, my initial thought would be to connect black white black white, that is how my mind works. . But it is saying black white white black.

Just something I might have done had I installed it. That is why I check everything about 3x.

Because the ac has a higher load, I am thinking it may be handing the load over to grid and that may be the problem.

Honest! I would have a text into the engineers!!! I simply thought I would share my troubleshooting skills, I have never seen your unit before.