seneysolar
Solar Addict
These dont like to be in continuous duty. The ends they crimp on will get very hot. Best to make your own cables or buy custom 4/0 cables from an outfit like Windy Nation.
How many amps is it trying to carry?
Beware of Amazon's class t fuses
- Thread starter Osmethne
- Start date
How many amps is it trying to carry?
Just always remember you want to provide the least resistance for power to flow. Adding something between the path like that washer adds huge amount of resistance. If the lug doesn't fit all the way flush because it is too tall then you can file the top edge off so it will fit. But as has been mentioned that is still a badly designed fuse holder for solar installs. The quality ones have a separate bolt that the cable lugs attach to so you don't have to remove the cable to replace the fuse.
ricardocello
Watching and Learning
150VDC HSF21J High Speed Fuse
Westking is renowned as a 150VDC HSF21J High Speed Fuse professional manufacturer and supplier in China, specializing in providing high quality 150VDC HSF21J High Speed Fuse to meet your requirements. Additionally, we offer competitive pricing for customized 150VDC HSF21J High Speed Fuse. By...
www.westking-fuse.com
The specifications look pretty good to me. Does not imply quality, but I don’t think the fuse is to blame.
I like how they call themselves “renowned”
#1 washers, #2 fuse holder
There is a torque specification!
Also, the fuse will put out 17.6W of heat at 200A.
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42OhmsPA
What's in a title?
Osmethne
Solar Enthusiast
150VDC HSF21J High Speed Fuse
Westking is renowned as a 150VDC HSF21J High Speed Fuse professional manufacturer and supplier in China, specializing in providing high quality 150VDC HSF21J High Speed Fuse to meet your requirements. Additionally, we offer competitive pricing for customized 150VDC HSF21J High Speed Fuse. By...
The specifications look pretty good to me. Does not imply quality, but I don’t think the fuse is to blame.
I like how they call themselves “renowned”
#1 washers, #2 fuse holder
There is a torque specification!
Also, the fuse will put out 17.6W of heat at 200A.
View attachment 221219
I was planning on replacing that fuse even before this event. My reason was that I can't find any UL or ETL listing on this fuse.
It's interesting there's a torque spec. Usually I tighten these things until I think I'm causing damage.
Osmethne
Solar Enthusiast
That's good to know about the automotive cables. I'll have to look into that more.
It usually spends about 3 or 4 hours a day around 70 to 80 amps. It's been carrying this load for the last 6 months. Which is why I think something other than the washers caused this. Don't get me wrong. I see the logic in it. It's just that if getting the washers wrong were enough to cause that much heat then I think I would have seen this happen months ago.
Brett V
Mad Scientist
I have 4 of these in service without issue.
Outback Power 300 Amp Class T inverter/ battery Fuse Block, holder & fuse | eBay
Outback Power 300 Amp Class T inverter/ battery Fuse Block, holder & fuse.
www.ebay.com
Bluedog225
Texas
- Joined
- Nov 18, 2019
- Messages
- 3,299
I was under the impression that this was the first time you put the thermal camera on it. Are you saying that you have thermal earlier and there was not a heat issue?
meetyg
Solar Addict
- Joined
- Jun 4, 2021
- Messages
- 1,221
Finally, an affordable class T fuse ?
I'm used to seeing these at double the price.
Of course we don't know much about the quality, but specs seem to good.
I just might be tempted to replace my MBRF fuses. Although I like the bolt-on style of the MBRF fuse holders. Keeping the fuse as close as possible to the battery terminal.
I'm used to seeing these at double the price.
Of course we don't know much about the quality, but specs seem to good.
I just might be tempted to replace my MBRF fuses. Although I like the bolt-on style of the MBRF fuse holders. Keeping the fuse as close as possible to the battery terminal.
DIYrich
Solar Wizard
Any opinion on South Bend fuses?
I bought one when Blue Sea was out of stock.
I bought one when Blue Sea was out of stock.
seneysolar
Solar Addict
Acts more like a spring to push the nut/bolt away.
Tulex
Solar Wizard
Hope they are good, they are in my first 3 batteries and going into my next 3. Made in USA, so there's that.
Also certified to UL blah blah... Doesn't mean UL listed though.
And not sure about the fact so many of the reviews are "free product" reviews.
But, that said, I'd trust it more than a Chinese knockoff.
cs1234
Solar Wizard
- Joined
- May 9, 2022
- Messages
- 2,791
This link is better, same price, more options, faster shipping from Amazon.
Osmethne
Solar Enthusiast
Partly. Really only the bright section at the bottom. I assume the rest is hot air trapped by the grill cover.
Osmethne
Solar Enthusiast
Thermal no. But when I first started moving serious power through it I would check it the first couple of months by putting my hand close to all the wiring to feel for heat. Pretty sure I would have noticed something that hot.
robbob2112
Doing more research, mosty harmless
Can anyone find a datasheet or a time/current curve on these? The only ones I can find with the datasheet are either littlefuse or busman. Mersen makes the same body style but you can't get them in the states except on Ebay
Bluedog225
Texas
- Joined
- Nov 18, 2019
- Messages
- 3,299
Pretty easy to test when you get a blue sea fuse holder (or similar). Be interesting to see the temps with a steel washer and without.
robbob2112
Doing more research, mosty harmless
Depends - stainless steel isn't the best conductor and would be a few watts warmer than one without that. But if the connection was loosening with the expansion and contraction it would gradually get hotter an hotter until some kind of failure happened.
The very very few places I needed a washer to make a lug sit right on a connection I use pure copper washers that I clean and polish. Then I use a coating of no-ox-id special A on all surfaces.
ricardocello
Watching and Learning
Electrical Conductivity of Materials - Blue Sea Systems
Engineering high quality marine electrical components for safety, reliability and performance
www.bluesea.com
Stainless Steel is conductively horrible!
Resistivity of Common Conductors
Table of common conductors and associated resistivities.
web.mit.edu
Osmethne
Solar Enthusiast
Like I said, that connection was still tight even after the event.
Stainless is not a good conductor of electricity, but the fastener shouldn’t be a conductor. Stainless is however, very close to the same rate of expansion as copper yet much stronger than a brass fastener. Since it expands at the same rate it will be less likely to emboss a depression in the conductor hence maintaining a tight grip later when cool and not loosening as much after many cycles like a steel fastener could.
robbob2112
Doing more research, mosty harmless
I see what you are saying - and looking at the picture more I get where the fuse block as melted from it.
And to your point - every added connection adds resistance to the run. The resistance adds heat and wasted power. Each safety device adds 2 connections minimum that must be prefect in every way to actually protect your design. Each fuse type and amp rating have different resistance as well.
How much is to much?
All of these below have 2 connections with a crimp per lug with plus the wire and lug. Everything done right it is negligable. Anything done wrong at any place it could be a fire waiting to happen.
Figure - on positive
BMS ->terminal ->fuse/breaker -> bus bar ->fuse/breaker -> inverter
on negative
BMS -> terminal -> disconnect switch *1 -> bus bar -> shunt *2 -> bus bar ->inverter
SCC would connect to the bus bars unless it is from an IAO inverter.
Note *1 - optional or part of a 2 pole breaker that does both pos and neg
Note *2 - could be a shunt per battery or one for all batteries
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