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EG4 3000 EHV-48 fire. Been running a 12 panel system with 2 EG4-lifepower batteries and the EG4 3000 EHV-48. Added the battery rack and 3rd battery

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Endsofearth

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EG4 3000 EHV-48 fire. Been running a 12 panel system with 2 EG4-lifepower batteries and the EG4 3000 EHV-48. Added the battery rack and 3rd battery4 days ago, charge got up to 91% each day but stopped there. Today we had more sunlight and charge was up to 95% at 1pm and at 2 was still at 95% when I checked it. I was near when I heard a loud POP and saw smoke coming out of EG4 unit. Error code 13 (over current or surge) . shut off switch, shut off panels, ran for fire extinguisher, when I got back battery cables under EG4 were also on fire. Smothered fire with CO2 (not the best for electrical fires). Shut off batteries and put out fire again. My panels are Q Peak duo blk-G5 310
310 watts
Short circuit amps9.83
Open circuit voltage 40.2
current at max power 9.36
Voltage at max power 33.12
max system voltage 1,000
EG4 is burned inside at top left corner and battery cables right below where they enter unit.
What caused this?
Any ideas? I was looking to add more panels (arriving Monday) and another EG4 Not ordered yet. Should I upgrade? Right now we are only running an RV Fridge, 2 laptops, water pump 5 min every 3-4 hours. and a few chargers, Ryobi cordless, weather station.
 

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Wow... that sounds scary..... Sorry it happened.

There is not a lot to go on so the following is little more than wild speculation:

The burning battery cable makes me think either 1) there was a short or something in the inverter that was drawing way too much current, or 2) there was a loose connection where the battery cables bolt to the inverter. The minimal load that is described does not seem enough to cause a fire even with a loose connection. Furthermore, the damage in the top part of the inverter seems unlikely to be from a loose connection at the bottom of the inverter. But if it was not a loose connection, what could cause a short??

Are all 12 panels all in series? That would be 12x40.2=482.4V for the array Voc. That seems too close to the Max 500V of the inverter. Could it be that you exceeded the PV input voltage? Can you tell if the fried board is part of the Solar Charge Controller? I assume you are in the northern hemisphere and it is fairly warm where you are..... and that would drive the voltage down. But...... there is something that is called the cloud edge effect where a cloud edge can refract the light and concentrate it on the panels.

The other hint that the problem is related to the SCC is that it seems that the batteries had quit charging before the problem. (There are other reasonable explanations for this so by itself it does not mean much.... it is only a hint).

Having said that, it would be a weird cascade of events for the PV voltage to cause a short on the Battery cables.


BTW: How is the system fused? It is concerning that the battery cables got hot enough to catch fire without a fuse blowing.
 
Each battery has a fuse, 100 amp. The battery cables were not shorting out or at least not fused together but the insulation was on fire. Unless there was a crack in the insulation and the cables were arcing. I pulled on all the wires before disconnection and did not find any that were loose. I think I should have a 100 amp fuse off the battery bank or a 125.
Panels were in series, suggestion to set up 2 banks may work better. The most voltage I saw was 412 volts. I was worried that the system was not working.
Output was fused at 20 amps and fed a single outlet then a cord to the RV, separate cord to water pump. Load a few minutes before was 380 to 400 watts at 120 VAC.
The cable insulation took a lot to put out, I shut down all 3 batteries and the cables kept relighting.
Thanks for the suggestions
 
What gauge are the wires for the PV, and for the Battery?
What type of wire insulation was it?
Was the wire UL Listed, 1000V PV Wire or the cheap LV wire they sell on Amazon?
Did you use a Torque wrench to secure every connection? (This should be standard practice guys.)

A loose PV connection, stray strands of wire, or anything that causes a path for current to flow across PV + to -, with a 450V string, will typically melt the connectors or terminals, but UL Listed PV wire does not catch fire, and definitely would not re-ignite.

If there were a short circuit at the Inverter DC bus, (Blown MOSFET/IGBT) it would draw maximum current from the battery and from the PV input simultaneously. It should blow the 20A PV fuse, and yes you should have a fuse or MC circuit breaker between the inverter and the battery bank to protect those cables. This could've easily started a battery fire and that would've been disastrous! I'm glad you're okay! This is why battery wires and PV wires should be in EMT conduit when they enter your home or garage, all the way to the inverter. All wires should be concealed, for your own safety.
 
PV uses 8 gauge wire, THHN 600 volt rated. (did not catch fire)
The battery cables that came with the EG4 were the ones that caught fire. Not sure what they are rated.
I used a cordless impact driver to set every connection then checked with lever type torque wrench to 1.6.
Thankfully this is all in a storage container until the house is built.
I like the idea of having the batteries outside the house.
 
The cables that come with the batteries are not large enough to carry multiple batteries in parallel to the inverter. I wonder how many amps were flowing on the cables.
 
timselectric said:
The cables that come with the batteries are not large enough to carry multiple batteries in parallel to the inverter. I wonder how many amps were flowing on the cables.
Click to expand...
The cables that came with the batteries run to the bus bar on the rack and are a lot smaller, the cables that came with the Inverter/charger are heavier and fit the connectors, I don't think larger cables would fit. I looked to see if larger would work. I just checked the gauge, the cables were #4.
 
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Just wondering, what is/was the charging amps set at, and also discharging amps?
 
I like the same setup off of the Will Prowse videos. Is there anyone else who has this setup, I've read about other problems but never fires with EG4.
 
timselectric said:
The cables that come with the batteries are not large enough to carry multiple batteries in parallel to the inverter. I wonder how many amps were flowing on the cables.
Click to expand...
Even if they have the gauge correct, it sounds like the insulation is wrong.

Also, what happened to the over current protection? If the inverter shorted the 48v DC bus, the breakers on each battery should have tripped. What are they 100 amps each?
So a max sustained current of 300 amps. With a typical breaker trip curve I'd expect a shorted DC bus to pull 1000's of amps.

I wonder what the interrupt rating is on the EG4 battery breakers? It may be they aren't rated to interupt the high short circuit current that the cells can provide.
 
Endsofearth said:
Each battery has a fuse, 100 amp. The battery cables were not shorting out or at least not fused together but the insulation was on fire. Unless there was a crack in the insulation and the cables were arcing. I pulled on all the wires before disconnection and did not find any that were loose. I think I should have a 100 amp fuse off the battery bank or a 125.
Panels were in series, suggestion to set up 2 banks may work better. The most voltage I saw was 412 volts. I was worried that the system was not working.
Output was fused at 20 amps and fed a single outlet then a cord to the RV, separate cord to water pump. Load a few minutes before was 380 to 400 watts at 120 VAC.
The cable insulation took a lot to put out, I shut down all 3 batteries and the cables kept relighting.
Thanks for the suggestions
Click to expand...
It sounds to me like the inverter developed an internal short.....perhaps something like a cascading failure where all the FETs failed in a short circuit... It seems unlikely but I have seen some pretty strange failures.

Of course that still leaves the question of why is shorted. Was it a plane old component failure or was there something external that triggered it.

I will say again that it is concerning that the cables got that hot but the fuses and BMSs did not shut down.... Something seems very wrong about that.

Endsofearth said:
Panels were in series, suggestion to set up 2 banks may work better.
Click to expand...
Yes, definitely. Even if the PV voltage had nothing to do with the failure, an Array Voc of 482V is asking for trouble. Even a cool day and the calculated Voc will go north of 500V.

diysolarforum.com

Adjusting Solar Panel Voc for temperature

When designing you solar panel system, it is important to adjust you solar panel Voc for temperature in order to ensure you do not over-voltage the PV inputs of your solar charge controller. This paper shows how to calculate the Temperature...
diysolarforum.com diysolarforum.com
 
Cyanlite said:
MPP Solar, SunGold, Growatts, and EG4 are made from same Chinese company (Voltronic)
Click to expand...

Well I thought that these Chinese inverters are clones of MPP Solar and EG4 as they look similar, turns out MPP Solar and EG4 are also made in China.
 
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