House burned down

[Hedges]

Where is "1-5 A"?

Type J

https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/fuses/bussmann-series-high-speed-fuses/bus-ele-ds-1048-dfj.pdf

"Ratings • Volts • 600Vac (or less) • 450Vdc (or less, 15-600A) • Amps 1-600A • IR • 200kA RMS Sym. • 100kA DC"


CHSF

https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/fuses/bussmann-series-high-speed-fuses/bus-ele-ds-10414-chsf.pdf

"Ratings • Volts - 500Vac/dc • Amps – 50-400A • Interrupting rating • Max AC – 200kA • Min AC 400% • Max DC – 50kA • Min DC 800%"


50kA or 100kA good for LiFePO4 banks with multiple cell strings.


Previously I was considering 4p16s (which could need such a fuse), but I do have concerns about individual cells sucking current not able to be isolated by BMS.

Now I'm thinking 16s4p, each 16s with its own BMS.

In that case, one 200A class T fuse per string of cells.
Combine with busbar.
Separate 2/0 wires to each inverter, not protected at near end (and 4p separate fuses don't protect against overload) but protected by 125A breaker in inverter.

In the event of a short, the 4 parallel fuses could deliver 800A but if 2/0 cable gets shorted it will fast-blow the fuse.

 

[user2562]

Am I reading this wrong from the data sheet, "50 kA DC (1-5 A)" I take that as being a 1-5 amp current for that fuse type?

thats on the tech specs for FWH ferrule type fuses that don't go beyond 30A. Different from FWH 300A blade end style.

https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/fuses/data-sheets/bus-ele-ds-720038-fwh-(.25-30)a6f.pdf

 

[CVCPJared]

I would need to heat the batteries and inverter in the winter. It can get to -10F here in Wisconsin. And at the same time that I would need to heat the insulated shed, I would be netting about 8-12kW / day making it completely pointless. All of my solar would go to heating the outbuilding and it probably wouldnt be enough.

Just need an R99 shed with dedicated geothermal heating. Totally worth it

 

[HighDesertDrifter]

I sympathize with you. Your build looked to be a professional build looking at your previous post.

When fuses blow, then there is a root cause for the fuse to blow as I found out with my 93 Dodge Ram truck when one of the fusible links blew and the mechanic changed out the link without determining the root cause and it blew again which left me stranded in a very precarious situation.

I know this is hard for you but for all of us in this forum that have their family at risk, the more that we can find out about this tragic loss the safer we will all fill. I have my 110kwhr LFP pack in the cellar of my home. If that caught on fire, then the whole house would go.

I have my Cells divided into two parts with two class t 200 amp fuses to protect the Cells. There are 128 -280 amp Cells. I did not put my Cells in a metal enclosure or compress them. They are on a nice piece of wood. This has really got me thinking about what I can do to protect myself further.

I am thinking about maybe fire blankets or some sort of a fire alarm that can be heard while sleeping two floors above the cellar.

Any suggestions would be appreciated. The simpler the better.

Check out Ceramic fiber, I use it as a heat shield where needed. Warning, the micro fibers are NOT good to inhale, use a mask when handling. There are various versions of this material, some are foil backed etc.
Ceramic Fiber on Amazon

 

[robbob2112]

Check out Ceramic fiber, I use it as a heat shield where needed. Warning, the micro fibers are NOT good to inhale, use a mask when handling. There are various versions of this material, some are foil backed etc.
Ceramic Fiber on Amazon

For rockwool they have spray that can be used to stiffen the sheets of it into panels. I would assume these can either use the same or similar ... Sometimes stiff sheets are easier to deal with than flexible stuff.... Just have to make sure the spray isn't flamable.

Rockwool also comes in stiff sheets verse bats and is similar to the stuff in the link, just not as pretty.

 

[thomBangor]

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.

Thank you for posting. I've been on this forum long enough to start believing the 'fires aren't a problem' hype. I built my 1st system in a shed and was planning to upgrade to an indoor unit this year. Your post persuaded me to repeat the shed thing instead. I appreciate it and my family does too! Thank you and sorry for your loss.

 

[Jejochen]

Thank you for posting. I've been on this forum long enough to start believing the 'fires aren't a problem' hype. I built my 1st system in a shed and was planning to upgrade to an indoor unit this year. Your post persuaded me to repeat the shed thing instead. I appreciate it and my family does too! Thank you and sorry for your loss.

Now the system is on the shed, it has other advantages. No more noise from the fans (was running 100% of the time: victron), and we have an extra space were the 1st battery was. Extra storage for the wife's stuff

 

[HighDesertDrifter]

Glad you all made it out safely! Stuff can be replaced.

Seems like every house fire I remeber here has either involved a failed fuse or a rack collapse?

Am I missing something? Or is that pretty much the case?

I have a smaller 2 x 300 ah 24 V system and don't fuse my batteries. Been running this way 8 - 10 years, LA batteries now Lithium thankfully no fires yet!

 

[Brucey]

There are 58V rated mega fuses for 48V nominal systems. Personally for a 100+kWh bank, I would be using class ts or midnite 125V 250A mnedc 250 DC breakers.

View attachment 212029

Just wanted to follow up because in the process of replacing my 58V 125A megafuse in my distributor with an 80V ceramic unit, I found that my 58V megafuse was damaged, presumably when it was torqued down. Couldn't be seen really until the positive cable was removed.

It was still passing current but running hot to the touch when it was passing 100A through from a 450/100, I noticed the positive was feeling hot when feeling with fingers with cover on but just thought that was normal.

With the 80V replacement in place there's barely any heat at all.

Something to keep in mind if there was a huge battery bank behind those.

 

[CVCPJared]

Just wanted to follow up because in the process of replacing my 58V 125A megafuse in my distributor with an 80V ceramic unit, I found that my 58V megafuse was damaged, presumably when it was torqued down. Couldn't be seen really until the positive cable was removed.

It was still passing current but running hot to the touch when it was passing 100A through from a 450/100, I noticed the positive was feeling hot when feeling with fingers with cover on but just thought that was normal.

With the 80V replacement in place there's barely any heat at all.

Something to keep in mind if there was a huge battery bank behind those.

View attachment 276181
View attachment 276182

Brucey, you mentioned having the MNEDC breakers before. I think it was off this thread giv8ng me the fear of burning things down - but i took that advice abmnd bought both T-class and mnedc Did you mount those in the expensive Midnight boxes or was that a DIY job?

 

[Brucey]

Brucey, you mentioned having the MNEDC breakers before. I think it was off this thread giv8ng me the fear of burning things down - but i took that advice abmnd bought both T-class and mnedc Did you mount those in the expensive Midnight boxes or was that a DIY job?

Total diy bud

Just couldn't swing the megabucks for the 1000A and 2000A midnite combiner boxes and they are gigantic, 3ft wide etc. I just ordered bus bars so I can double up with another 250A as I'll soon be approaching the single breaker limit during peak solar charging. Rather do that than go with the lynx shunt as there's some reports of failures and the smartshunt 500A is rock solid reputation wise.

 

[ricardocello]

Brucey, you mentioned having the MNEDC breakers before. I think it was off this thread giv8ng me the fear of burning things down - but i took that advice abmnd bought both T-class and mnedc Did you mount those in the expensive Midnight boxes or was that a DIY job?

You haven't seen the famous flying midnite breaker photo? oh he just reposted it above.

 

[SomethingAppropriate]

Total diy bud

Just couldn't swing the megabucks for the 1000A and 2000A midnite combiner boxes and they are gigantic, 3ft wide etc. I just ordered bus bars so I can double up with another 250A as I'll soon be approaching the single breaker limit during peak solar charging. Rather do that than go with the lynx shunt as there's some reports of failures and the smartshunt 500A is rock solid reputation wise.

View attachment 276191

I got one of those too, I think because of you!

Why is there that 2 inch long copper pipe on these for the lugs?

I should have asked 3 months ago/

 

[Brucey]

I got one of those too, I think because of you!

Why is there that 2 inch long copper pipe on these for the lugs?

I should have asked 3 months ago/

It's to adapt from m8 on the distributor to m10 studs on the mnedc250, not needed I could have drilled out the distributor or used a jumper. It's solid copper, was from another project where I was going to do a diy lynx shunt with 3d printed case, with 275a victron switch and smartshunt. However I need more than 250a so doubling up on the mnedc250s is the easiest solution I can find.

 

[CVCPJared]

Total diy bud

Just couldn't swing the megabucks for the 1000A and 2000A midnite combiner boxes and they are gigantic, 3ft wide etc. I just ordered bus bars so I can double up with another 250A as I'll soon be approaching the single breaker limit during peak solar charging. Rather do that than go with the lynx shunt as there's some reports of failures and the smartshunt 500A is rock solid reputation wise.

View attachment 276191

Ok cool. Yeah, same boat. I thought it was some kind of standard "monster breaker" that had a standard mount with a name, doesnt seem to be such luck.

Got $20 8x8x4 enclosures from Home Depot, was going to use a multi-tool and see how they turn out

 

[Sonne]

Just wanted to follow up because in the process of replacing my 58V 125A megafuse in my distributor with an 80V ceramic unit, I found that my 58V megafuse was damaged, presumably when it was torqued down. Couldn't be seen really until the positive cable was removed.

It was still passing current but running hot to the touch when it was passing 100A through from a 450/100, I noticed the positive was feeling hot when feeling with fingers with cover on but just thought that was normal.

With the 80V replacement in place there's barely any heat at all.

Something to keep in mind if there was a huge battery bank behind those.

View attachment 276181
View attachment 276182

I like that form factor - is the fuse itself a victron product or just the plastic carrier it’s sitting on? I’d like to find a fuse which can sit local to battery terminals but which remains contained in the event of a failure, rather than the type which can spit out molten metal and start a fire like we’ve seen at the start of this thread.

 

[Brucey]

I like that form factor - is the fuse itself a victron product or just the plastic carrier it’s sitting on? I’d like to find a fuse which can sit local to battery terminals but which remains contained in the event of a failure, rather than the type which can spit out molten metal and start a fire like we’ve seen at the start of this thread.

They are Victron, 80V 5 packs. Have to scroll down on the list they are at the bottom. You may want to consider mrbf type fuses on your battery terminals, they will have a higher aic rating (10,000 AIC) than a megafuse at perhaps 3000 AIC. Class t being 20,000 aic and mnedc250s at 50,000 aic. And then use the 80V megas for your loads.

Victron MEGA-Fuse 32V/48V/80V

MEGA-Fuse by Victron Energy are designed for heavy-duty applications, providing superior protection for battery and alternator systems. Ideal for high current and heavy-gauge applications.

bluemarine.com

 

[Sonne]

They are Victron, 80V 5 packs. Have to scroll down on the list they are at the bottom. You may want to consider mrbf type fuses on your battery terminals, they will have a higher aic rating (10,000 AIC) than a megafuse at perhaps 3000 AIC. Class t being 20,000 aic and mnedc250s at 50,000 aic. And then use the 80V megas for your loads.

Victron MEGA-Fuse 32V/48V/80V

MEGA-Fuse by Victron Energy are designed for heavy-duty applications, providing superior protection for battery and alternator systems. Ideal for high current and heavy-gauge applications.

bluemarine.com

Thank you! I’ll look at MRBF. The main feed from battery bank into my load system is already fused with NT00 type fusing, I’m just looking for something to protect the parallel cell banks from discharging into each other in the case of a cell internal short, as this would not trip the main fuse.

I was going to use ANL fuses for this purpose but kinda lost faith in them due to potential for spitting molten metal out.

 

[Crowz]

Ok cool. Yeah, same boat. I thought it was some kind of standard "monster breaker" that had a standard mount with a name, doesnt seem to be such luck.

Got $20 8x8x4 enclosures from Home Depot, was going to use a multi-tool and see how they turn out

That's what I did basically.

Got this off amazon :

Amazon.com

Then mounted the bus bars, precharge resistor stuff and the breaker in it.

Even mounted the victron smart shunt inside it.

 

[Brucey]

Thank you! I’ll look at MRBF. The main feed from battery bank into my load system is already fused with NT00 type fusing, I’m just looking for something to protect the parallel cell banks from discharging into each other in the case of a cell internal short, as this would not trip the main fuse.

I was going to use ANL fuses for this purpose but kinda lost faith in them due to potential for spitting molten metal out.

Yes be careful of parallel strings treat them with respect. I would spend just as much effort on protecting the parallel strings as you do the main feed out to the loads.

 

[CVCPJared]

That's what I did basically.

Got this off amazon :

Amazon.com

Then mounted the bus bars, precharge resistor stuff and the breaker in it.

Even mounted the victron smart shunt inside it.

View attachment 276291View attachment 276292

Nice. That's a much larger and nicer box than the HD ones, but gonna have to make do. Glad to see it's been done

 

[CVCPJared]

That's what I did basically.

Got this off amazon :

Amazon.com

Then mounted the bus bars, precharge resistor stuff and the breaker in it.

Even mounted the victron smart shunt inside it.

View attachment 276291View attachment 276292

2 days of revisiting and staring at your beautiful box and my ugly ones was bugging me. Then 1 size that should work well went on sale and they got me lol. Home Depot boxes are going back, thanks again for the recommendation

 

[Brucey]

I picked up one of these 250A 14 position midnite battery combiner boxes, thinking mount an mnedc250 on the side:

They make a version with integrated 250A breaker (different style than the mnedc) but way more expensive grabbed this new on ebay for $250. If you are 9k with 250A limit may be an option for some,

https://www.midnitesolar.com/productPhoto.php?product_ID=686&productCat_ID=9&sortOrder=1&act=p

 

[Crowz]

2 days of revisiting and staring at your beautiful box and my ugly ones was bugging me. Then 1 size that should work well went on sale and they got me lol. Home Depot boxes are going back, thanks again for the recommendation

Your going to love that plate on the inside that covers the center part. I can remove it and then mount things like the busbar and the victron smart shunt to it and then reinstall the plate back inside afterwards.

 

[Batvette]

I sympathize with you. Your build looked to be a professional build looking at your previous post.

When fuses blow, then there is a root cause for the fuse to blow as I found out with my 93 Dodge Ram truck when one of the fusible links blew and the mechanic changed out the link without determining the root cause and it blew again which left me stranded in a very precarious situation.

I know this is hard for you but for all of us in this forum that have their family at risk, the more that we can find out about this tragic loss the safer we will all fill. I have my 110kwhr LFP pack in the cellar of my home. If that caught on fire, then the whole house would go.

I have my Cells divided into two parts with two class t 200 amp fuses to protect the Cells. There are 128 -280 amp Cells. I did not put my Cells in a metal enclosure or compress them. They are on a nice piece of wood. This has really got me thinking about what I can do to protect myself further.

I am thinking about maybe fire blankets or some sort of a fire alarm that can be heard while sleeping two floors above the cellar.

Any suggestions would be appreciated. The simpler the better.

If that went up Im not sure the fire dept in a major city could save the house.