House burned down

D71 said:

Not sure what was changed but think op changed batteries….after these were put up. Link at bottom.

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LFP Powerwall

a few pictures of my own built 'home energy system'. I run my house, workshop and if needed charge my tesla model S with it. currently 3 multiplus 2 5 kVa units for 3-phase system, 48 V battery: 3 banks of 16 200 Ah cells, monitored by batrium. The victron system runs the ESS template. One of...

diysolarforum.com

The wire way melted away.

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The op changed shelves and Added a 7th string after. The black cabinet is gone. There are pictures in the powerwall thread by the OP.

robbob2112 said:

The the subdivision down near Cortez me and the wife are moving to requires an electrical permit be pulled when being built, but no inspections after that. The PoCo will only inspect if you grid tie and sell back.

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Had a friend ask to use my electrical license in a rural Ohio county. He said Duke utility didn’t require a permit just needed install by a licensed electrician. So I went to friends, checked his work, put some detox on fittings. And the Utility hooked him up.

robbob2112 said:

The op changed shelves and Added a 7th string after. The black cabinet is gone. There are pictures in the powerwall thread by the OP.

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Jejochen said:

So, after 4 to 5 years of working flawless, the 100 kwh lifepo4 battery caught fire at night and burned our house down. Luckily our family just made in out on time.
Inspection of the fire expert revealed that a melt fuse melted, and created an arc between the 2 points wich ultimatly started the fire.
So i learned to not use melt fuse anymore, plus once the house is rebuild, i will put the new system in a seperate shed outdoor.

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Thought I'd share this. It was a set of AC 600 volt fuses on a 500 volt DC feed from the panels on a nice sunny day. If this were properly rated fuses, I wouldn't have taken this picture.

The current from the panels exceeded expectations and one of the fuses blew, effectively creating a 10KW arc lamp on my wall. This is why I have a renewed respect for electrical codes.

dianea said:

It was a set of AC 600 volt fuses on a 500 volt DC feed from the panels

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Fuses or breakers between panels and inverter create more fire hazard than safety benefits.

AntronX said:

Fuses or breakers between panels and inverter create more fire hazard than safety benefits.

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I think you have to use a fuse if paralleling more than two strings - I don’t have parallel strings; mine are all in series as I wanted high voltage. We did put in 600v DC Midnite SPDs between the panels and inverters. I don’t remember what the connectors that we used are called. They were like an industrial wego but the wires were secured with screws (I think). I’ll ask my electrician next time I see him.

SilverbackMP said:

I think you have to use a fuse if paralleling more than two strings

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Even that is bogus reason if you really model most probable panel short circuit failure. Once you go above 2 panels in series per string you can have 1 bypass diode fail short and not cause excessive sink current across remaining cells. You would need 0.7V per cell to make it absorb 10A. If you got a bunch of panels in parallel (none in series) then fuses on each panel make sense.

AntronX said:

Fuses or breakers between panels and inverter create more fire hazard than safety benefits.

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Would you just do something like an imo disconnect between them?

dianea said:

Thought I'd share this. It was a set of AC 600 volt fuses on a 500 volt DC feed from the panels on a nice sunny day. If this were properly rated fuses, I wouldn't have taken this picture.

The current from the panels exceeded expectations and one of the fuses blew, effectively creating a 10KW arc lamp on my wall. This is why I have a renewed respect for electrical codes.

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I'm guessing that was a steel enclosure and not the random Amazon plastic combiner boxes.

Brucey said:

Would you just do something like an imo disconnect between them?

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Sure something like PV isolator switch. But if you insist on using fuses/breakers then at least install them inside steel enclosure. Same for PV surge protectors. Another interesting point is that fuses are ineffective until 2x rated current. So for 10A panels you'd use 15A fuse that will not blow in reasonable time until 30A fault. That means 4 parallel strings are needed (1 faults and 3x10A supply current).

dianea said:

Thought I'd share this. It was a set of AC 600 volt fuses on a 500 volt DC feed from the panels on a nice sunny day. If this were properly rated fuses, I wouldn't have taken this picture.

The current from the panels exceeded expectations and one of the fuses blew, effectively creating a 10KW arc lamp on my wall. This is why I have a renewed respect for electrical codes.

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What sort of fuse was it? I ask because a 600v fuse on a 500v feed shouldn't matter at all. With fuses it is all about the current running through it. Most fuses are way over the voltage used. The voltage limitation is all about the insulation.

AntronX said:

Sure something like PV isolator switch. But if you insist on using fuses/breakers then at least install them inside steel enclosure. Same for PV surge protectors. Another interesting point is that fuses are ineffective until 2x rated current. So for 10A panels you'd use 15A fuse that will not blow in reasonable time frame until 30A fault. That means 4 parallel strings are needed (1 faults and 3x10A supply current).
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Yes, metal enclosures for sure. I'm switching my mnpv6 combiner box over to fuses from 150V mnepv breakers now that I have the 450/100. Also a good place to transition from PV cable to fine stranded to go to the sccs.

robbob2112 said:

Most fuses are way over the voltage used. The voltage limitation is all about the insulation.

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No! The limitation is often the ability to break DC voltage (DC rated AIC).

yabert said:

No! The limitation is often the ability to break DC voltage (DC rated AIC).

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The DC voltage rating isn't the AIC rating - they are different all together. The voltage rating is where it won't arc over/through the insulation into anything else. The AIC rating is the ability to break an arc inside when it opens. The AIC is always rated in amps or kilo-amps, not volts

AIC rating can vary with voltage.

Hedges said:

AIC rating can vary with voltage.

Interrupt Capacity

10000A @ 14V DC 5000A @ 32V DC 2000A @ 58V DC

MRBF Terminal Fuse - 30A - Blue Sea Systems

Space-saving ignition protected fuse for 30 to 300 Amp loads. Must use with Terminal Fuse Block.

www.bluesea.com

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Agreed, but a 600v fuse used on a line with 500vdc and 30amps shouldn't have a problem so long as the 30 amps is not exceeded.

But, the resistance of fuses does vary by the amp rating, which means heat output varies by amp rating.

From my testing with the class T and Chint fuses the higher the amp rating the lower the internal resistance.

From looking back earlier in this thread where I posted a picture of a bunch of fuses side by side, the larger the higher the voltage rating the larger the fuse. The Class T in the picture are rated 125vdc and 160vdc. The larger is physicaly bigger. The Chint have a way higher voltage rating and much larger. But their internal resistace is higher so more heat loss. But they sit in the holder in open air to disipate the heat.

See


Now, all that said - our friend @dianea had a fuse mounted to a DIN rail and looked like screwed to a sheetrock wall verse inside an enclosure and she was kind enough to post a picture of it as a warning - so I was asking for any details she could provide about the fuse itself. As in type/voltage/amps from which we can see why it did what it did.

I suspect from the picture there was a short somplace or more likely the fuse was being run near its amp limits and it heated up like the filament in an old light bulb. and burned the wall and melted whatever the casing it. That looks like a fuse holder that has a flip out door and you put a fuse inside it.


P.S. @dianea - if you have more pictures I would like to see one from farther way showing all the damage, looks like the wire on the right had a melted sheath.

robbob2112 said:

The voltage rating is where it won't arc over/through the insulation into anything else.

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The voltage rating is so that it can safely break an arc and not explode/catch fire and cause this forum thread.

From dianea: ''It was a set of AC 600 volt fuses on a 500 volt DC feed from the panels''
AC voltage is way easier to break than DC voltage.
It's why some class T fuse have 200ka AC interrupting rating, but only 20ka DC rating.

yabert said:

From dianea: ''It was a set of AC 600 volt fuses on a 500 volt DC feed from the panels''
AC voltage is way easier to break than DC voltage.
It's why some class T fuse have 200ka AC interrupting rating, but only 20ka DC rating.

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I missed the AC part of that, but most AC fuses are also rated as DC fuses at lower volts. And it makes a difference on fuse type of how much lower that rating is.

I do see your point now - valid - so she was using the incorrect rated fuse in that because her string voltage was so much higher that.

I think she was using something like this - (random off amazon) - 600vac might be a 380vdc fuse....

robbob2112 said:

What sort of fuse was it? I ask because a 600v fuse on a 500v feed shouldn't matter at all. With fuses it is all about the current running through it. Most fuses are way over the voltage used. The voltage limitation is all about the insulation.

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The vaporized fuses used to be Littlefuse CCMR 15, rated "600 VAC or less " no DC rating at all. This was in my shop and happened during destructive FAFO testing of improper parts. The fuses were installed in a surplus three phase Allen Bradley 1492-FB3C30 fuse holder with indicators. It's indicators weren't needed this time to let me know the fuses had failed. This experiment may suggest using wrong fuses for the wrong application with no enclosure might cause infinite more harm than any good. And a reminder that rated enclosures are a good idea...

robbob2112 said:

So one thing I notice in all the pictures of the battery cells. It appears there is no separator between the individual cells? Seems like I remember reading that if they are under any sort of compression or even straight confinement sonthe expansion is limited there should be some sort of separator used?

I know in one of the threads the OP had one or more vented cells. Could that be a cause? Cell vent which off-gases hydrogen among other things. Shorted cell generates heat and with the hydrogen confined it just needs a spark. If the high current causes the fuse to blow but arc keeps it alive it will melt the casing and catch fire. One reason I don't like the ANN, ANL, and all their cousins.

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Where do you get they off gas hydrogen from?
I know lead acid off gas plenty

All I see is this which doesn't directly say that

SparkyJJO said:

So uh where are you supposed to store propane tanks?
<eyes the 20lb tank in the garage>

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make concrete boxes for it with hardie backer board
I put my batteries inside a big box as well
Probably need a vent outside for the propane tanks? but it'd protect them from other stuff getting at them
We have always had big tanks that are like 30ft away from the house sit outside, never inside

You are looking at Lipo batteries. When the electrolyte breaks down from a shorted or overcharged cell...i.e high temp vent


1. **Carbon Dioxide (CO2)** - From the breakdown of organic carbonate solvents.
2. **Carbon Monoxide (CO)** - From incomplete combustion or decomposition of the electrolyte.
3. **Hydrogen (H2)** - Generated from the decomposition of organic materials and electrolytes under extreme heat.
4. **Phosphorus Pentafluoride (PF5)** - Produced from the decomposition of LiPF6, a common lithium salt in the electrolyte.
5. **Phosphorus Oxyfluoride (POF3)** - Another decomposition product from LiPF6.
6. **Hydrogen Fluoride (HF)** - Forms when PF5 and POF3 react with moisture; highly corrosive.
7. **Lower Alkanes and Alkenes (e.g., methane, ethane)** - These can form through the breakdown of organic solvents under severe thermal conditions.

From the article you posted -

The composition of off-gas on average is very similar between NMC and LFP cells, but LFP batteries have greater hydrogen content, while NMC batteries have greater carbon monoxide content.

I’ve got GAS.
Copper yellow tubing into black iron pipe which was fresh from China.
Mine.


BY CODE…420lb /120 gallon propane but anything larger goes 10feet away from home. Some HOA have additional higher requirements only propane allowed has to be buried tanks 10ft from home.

My garage right now. Shhhssss… sometimes these tanks leak. I never leave the valve open unless using. But. ….





Never ever tripped ….carbon monoxide alarm. Never ever. Somebody say can’t do that then they park … Charging EV or ICE half tank fuel or less…… in attached garage. Hush.

Now why did OP system go up in smoke? Was it in the garage? Some put their Solar inverter generators in home and park them…wire to pv and even tie into their home electrical system. Playing with fire. My small in home lifepo inverter generator setup…. Is Sitting next to my laptop with a battery that is not LiFePo in my closet. Hmmm….. had laptop for long time. No fires.

I was looking at a new lifepo power inverter generator setup the other day so went back to get screen shot to share. If they can’t get the advertising correct should they be trusted? Notice….ad.



Govt Test - start - intentional fires - explosions…for battery science and safety. These things in past were tested before being sold to public….UL Not anymore…..make it sell it let public test it until there is a problem. Then govt comes in.

More fun

Ppl are living dangerous. We do it all the time. The Samsung cell phones use to go up in flames too. the old disposable butane cigarette lighters were stated never to be around welding or cutting because spark would burn through - melt lighter housing and lighter explode. Some Ppl used them to light torch. I’ve used a butane soldering iron for years..
Stored energy - Dangerous

Notice Amazon Advertising. Caveat Emptor - Buyer Beware REASONABLE as Ignorance is no excuse….question becomes what is “reasonable” for burden. Also why you see sneaky disclaimers….example real estate agents often put up seller has to verify all stated is truth…ie: size home, property lines, school districts, so on.

“‘’’’’’
Cornell Law School Website.

caveat emptor​

Primary​

Caveat emptor is a common law doctrine that places the burden on buyers to reasonably examine property before making a purchase. A buyer who fails to meet this burden is unable to recover for defects in the product that would have been discovered had this burden been met. The phrase “caveat emptor” is Latin for “let the buyer beware.”
Caveat emptor principles are generally still followed today; however, they are subject to exceptions. Under the doctrine of concealment, for example, a seller who withholds material information when they have a duty to disclose is not protected by caveat emptor.
See, e.g. SEC v. Zandford, 535 U.S. 813 (2002).
See: Commercial law, Real property, Personal property
[Last updated in July of 2022 by the Wex Definitions Team]
“‘’’’

Ppl used to get sued for false advertising - govt had an agency just for that purpose Consumer Protection Agency.

D71 said:

I was looking at a new lifepo power inverter generator setup the other day so went back to get screen shot to share. If they can’t get the advertising correct should they be trusted? Notice….ad.

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Looks like some kind of possible scam while leveraging/cloning the Bluetti brand - BigBlue....

Brucey said:

Looks like some kind of possible scam while leveraging/cloning the Bluetti brand - BigBlue....

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Them saying it is “fuel type: lpg” was hilarious too. Crazy thing …. Hard to know what to trust as safe anymore. Most everything is accessed or unknown risk. We live in a technological risk and potential danger for everything. like reading side effect on medicines. Why labels are there.

It is a crazy world. Titanic ….. sub going to see the Titanic = Titan
Those recorded bangs which were just released were last thing the crew heard in a ms before it registered for the failure. Died near instant.

The Navy reported hearing those bangs in 1 news article…. Long distance away.

I bet the pictured fire at OP’s place made some crazy noise. He thought it was all figured out too. Comfortable even convinced. The story of Titanic and Titan. Same same comfortable convinced. Reality is Dangerous controlled but then the smoke gets out..

Caveat Emptor.

Me am looking at these batteries.



But looking at these too.




Hmmm imagine that sitting in your living room. Looks like modern furnishings. The EG4 battery has some kind of fire extinguisher built in their battery system Wonder what it is for that extinguisher?
HALON works well with fires but can kill everybody in closed room-space. Put out the fire but everyone dies because oxygen levels depleted. Win lose.