diy solar

diy solar

Shunt snapped and caused a fire🔥

Some of my Observation, which a few people have mentioned some of them already.

LOOK AT MY ARROWS:
Analysis.jpg
1) The burned green copper is the wire that got the hottest and it's worst on the Right breaker in the zoomed in picture Above.

2) That is also the only breaker that is Still fully in the ON state. The other seemed to have worked properly, but that one failed.

3) The Wire is Frayed broke just at the point on the Table where it seems like the top half of the Metal Table bar has been welded by the Wire.

Thanks for sharing.
 
k490 said:
Makes me rethink using wood for a battery box. I have a mig welder and some steel. Need to treat these like Lipos charge them in a wood stove.
Click to expand...
I wouldn't be so worried about it.
I plan to make my next rack out of steel (if I don't find a cabinet).

The major reason I'll use steel is for strength... Add a couple lift points and I can easily pick it up with the engine hoist when I move.

Any install can have major issues if things are done incorrectly or cheaply.

Mine are currently happily exposed in a wooden rack.
 
robby said:
Some of my Observation, which a few people have mentioned some of them already.

LOOK AT MY ARROWS:
View attachment 197892
1) The burned green copper is the wire that got the hottest and it's worst on the Right breaker in the zoomed in picture Above.

2) That is also the only breaker that is Still fully in the ON state. The other seemed to have worked properly, but that one failed.

3) The Wire is Frayed broke just at the point on the Table where it seems like the top half of the Metal Table bar has been welded by the Wire.

Thanks for sharing.
Click to expand...
What breakers were these?
 
robby said:
Some of my Observation, which a few people have mentioned some of them already.

LOOK AT MY ARROWS:
View attachment 197892
1) The burned green copper is the wire that got the hottest and it's worst on the Right breaker in the zoomed in picture Above.

2) That is also the only breaker that is Still fully in the ON state. The other seemed to have worked properly, but that one failed.

3) The Wire is Frayed broke just at the point on the Table where it seems like the top half of the Metal Table bar has been welded by the Wire.

Thanks for sharing.
Click to expand...
Looks like either the insulation melted off and arced into the shelf support because the battery was still on or the insulation was frayed as you say and shorted into the shelf and ate away at the metal.
 
I did a search of other posts by the OP and humidity issues were discussed, condensation.
The particle board as the failure point certainly comes to mind, since humidity and particle board are a bad combination,
as does the higher intensity (appearance) fire on the lower row: ie if the upper shelf collapsed onto the lower one.

I don't see a mechanisim for the shut to be the cause, unless over current caused it.
I see the failure being either cell over voltage -- leading to venting leading to ignition
Or the collapse of a shelf leading to damage/short/ venting. hard to know from the limited information.
I would like to know two things: 1. what is the amperage of those 3P MCCB. (why are they 3P?) and 2. what is the size of the PV system, what amperage does it send to the ESS, what are the controls over that PV current?
robbob2112 said:
Looks like either the insulation melted off and arced into the shelf support because the battery was still on or the insulation was frayed
Click to expand...
if this was the cause, we would expect the breaker to cut the current. unless the cable shorted between the battery and the shelf before the breaker. or the breaker fused closed first. why is that breaker still closed after this event?
 
42OhmsPA said:
Wow that looks miserable, fortunately it wasn't worse.

Are you sure the shunt was the root cause? Is it possible one of the particle board shelves collapsed causing a dead short and the shunt to fail?
The shunt was on the negative, correct?
Click to expand...
Reviewing the photos again it sure looks like those shelves weren't up to the task.
Screenshot_20240223-194854__01.jpg

OffGridForGood said:
I did a search of other posts by the OP and humidity issues were discussed, condensation.
The particle board as the failure point certainly comes to mind, since humidity and particle board are a bad combination,
as does the higher intensity (appearance) fire on the lower row: ie if the upper shelf collapsed onto the lower one.
Click to expand...
Agreed.
 
If you look at the photo I zoomed in, the vertical leg of the shelf was eaten away, likely there was current leakage between shelving, and arcing started the fire.

I will ALWAYS take before pictures of anything I build, and post them on this forum for all the experts, armchair or otherwise to peruse and critique.
 

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robby said:
Some of my Observation, which a few people have mentioned some of them already.

LOOK AT MY ARROWS:
View attachment 197892
1) The burned green copper is the wire that got the hottest and it's worst on the Right breaker in the zoomed in picture Above.

2) That is also the only breaker that is Still fully in the ON state. The other seemed to have worked properly, but that one failed.

3) The Wire is Frayed broke just at the point on the Table where it seems like the top half of the Metal Table bar has been welded by the Wire.

Thanks for sharing.
Click to expand...
Idk, all of that could have happened once the cells started venting into the fire creating a flamethrower effect…
 
robby said:
Some of my Observation, which a few people have mentioned some of them already.

LOOK AT MY ARROWS:
View attachment 197892
1) The burned green copper is the wire that got the hottest and it's worst on the Right breaker in the zoomed in picture Above.

2) That is also the only breaker that is Still fully in the ON state. The other seemed to have worked properly, but that one failed.

3) The Wire is Frayed broke just at the point on the Table where it seems like the top half of the Metal Table bar has been welded by the Wire.

Thanks for sharing.
Click to expand...
Above the arrow you have pointing down there is a LOT of frayed strands not in the breaker… why?
 
Supervstech said:
If you look at the photo I zoomed in, the vertical leg of the shelf was eaten away, likely there was current leakage between shelving, and arcing started the fire.

I will ALWAYS take before pictures of anything I build, and post them on this forum for all the experts, armchair or otherwise to peruse and critique.
Click to expand...
and since this was before that main breaker - it didn't trip and cut off the circuit.
 
I threw together a bunch of old Caleb cells in a toolbox, and am rigging everything together for a 3ish kWh portable power station…
I will start a thread when I finish with it in the power station forum
 
But, what caused the insulation on that heavy cable to fail at the steel shelf rail?
Surely there was no abrasion no reason for the cable insulation to rub through right at the angle iron rail? This is a stationary ESS.
What caused that cable insulation to fail at that rail to create the arc?
If the shelf above failed, and drop, with 200 lbs of cells on it...maybe that?
 
OffGridForGood said:
But, what caused the insulation on that heavy cable to fail at the steel shelf rail?
Surely there was no abrasion no reason for the cable insulation to rub through right at the angle iron rail? This is a stationary ESS.
What caused that cable insulation to fail at that rail to create the arc?
If the shelf above failed, and drop, with 200 lbs of cells on it...maybe that?
Click to expand...

Welding cable insulation will always fail if exposed to a thin metal edge.
 
OffGridForGood said:
But, what caused the insulation on that heavy cable to fail at the steel shelf rail?
Surely there was no abrasion no reason for the cable insulation to rub through right at the angle iron rail? This is a stationary ESS.
What caused that cable insulation to fail at that rail to create the arc?
If the shelf above failed, and drop, with 200 lbs of cells on it...maybe that?
Click to expand...
I would feel like the insulation probably melted off that wire from fire or short current. A knock on failure from the original short.
 
But, let's consider:
this is a very large ESS, and has likely been running quite some time, - That would be a good question actually - OP How long has this set up been running?
The edge of any standard shelf angle iron is not sharp, it is rounded off. AND the shelf angle is painted.
Something caused the short to take place.
The fact that all the other breakers are tripped except this one, seems to be a clue to the cause.
 
Want the limber fine-strand wire for a few reasons, including less stress on battery terminals.
Is there a suitable sleeve sufficient for mechanical protection?
Convolex? braid? BX?
 
k490 said:
Makes me rethink using wood for a battery box
Click to expand...
42OhmsPA said:
I wouldn't be so worried about it.
I plan to make my next rack out of steel (if I don't find a cabinet).

The major reason I'll use steel is for strength... Add a couple lift points and I can easily pick it up with the engine hoist when I move.

Any install can have major issues if things are done incorrectly or cheaply.

Mine are currently happily exposed in a wooden rack.
Click to expand...
It is a double-edge sword really:
Steel = conductive = potential problems
Wood = flammable = potential problems
Steel lined with tile backer or FR-4 on every surface, but what about the cable entry points?
I have used plywood, and fuses, quality BMS, good cables and proper sizes for these.
Plus heat and smoke detectors...that alarm next door where I live, a safe distance away!

Sorry not trying to detour from the original discussion. What caused the fire? (and change the Post Tiltle - we don't know the shunt is the cause (or not) shouldn't put this in the title.)
 
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