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diy solar

Do fuses work at all?

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actually in boats/cars, with a fixed connection (ring terminal to bolted connection, battery terminal to battery) wherever vibration exists, soldering a terminal can lead to wire breakage long term.
A weathertight sealed crimp is much better.
Agree
 
I am a HUGE fan of solder. Yes crimp but then solder.
A lot of my back round in wiring cars . With vibration and things going from hot to cold sooner or later the connection can fail.
Soldering after crimp insures a much better connection long term.
I also like to use diaelectric where I can on bare connectors.
as others have pointed out... in high reliability areas (military, space, high vibration environments, etc.) crimping is always the method of choice.
and soldering after crimping is not really a good idea.
when done correctly, crimping is superior to solder..but notice the caveat which is very important "when done correctly".
If you do not have the right tools, yea, just solder hehe
 
actually in boats/cars, with a fixed connection (ring terminal to bolted connection, battery terminal to battery) wherever vibration exists, soldering a terminal can lead to wire breakage long term.
A weathertight sealed crimp is much better.

I completely agree.

This solder/crimp argument has been had many times on the forum and rarely has anyone changed their mind.

However, after studying the issue, I gave up soldering for these type connections after decades of soldering.

I still get my solder smoke fix on building circuits :cool:
 
It's your fuse holder. Get a real fuse holder and maybe ditch the ANL type altogether. If this is the fuse immediately downstream from your battery then consider a Class T fuse.

There was a post a few months back where the forum member came close to a fire because his fuse holder melted down. Cheap fuse holder.
 
when done correctly, crimping is superior to solder..but notice the caveat which is very important "when done correctly".
I have seen way too many crimps done with the wrong crimp tool, over crimped to the point where it cuts some wires, or under crimped to where is will not stay on long term.
That being said, with the broad range of users on here and from what I have experienced in the field, I stick to how I do it but completely understand where some of you are coming from.
 
Do you have a picture or a link to your fuse holder? Are you fuse holder terminals clean?
 
The wire chart shows that 2/0 should take up to 300a

Sure, if you're using heat resistant wire insulation such as TBS, SA, or SIS, and if you're ok with the wire nearly reaching 200F in normal operation. Not to mention the huge resistive losses that turning the wire into a room heater will result in.

Keep in mind that your shunt meters sample the current frequently, but not continuously, so they will likely miss short huge overcurrent spikes.

Trusting them more than a fuse seems a little backward.

Regardless, it appears your problem is complex enough that we really need a full system diagram, including cable lengths, loads, and sources as it could be something more esoteric such as inductive spikes, cable length issues, etc.

If you want a breaker, use a breaker. There's no requirement to use a fuse, and given that you've blown more than one, a breaker will save you money since you can clear the fault and reset it, rather than buying another fuse.
 
Personally, I like MRBF fuses. I've used them on marine systems and carried them over to my solar installation at my cabin. It really takes the crappy fuse holder problem out of the picture. Blue Sea makes good ones.

 
See post #8 for a link to it.

Baomain brand.

That’s my primary suspect in this mystery. ?

First I checked fuse time curve.
Then I looked at the fuse holder.

How about a picture of your cables connected to your fuse and your fuse holder?

Wires getting hot just near the fuse indicates heat is generated there.

Here's what I'm hoping to find out is the problem:
Because that fuse holder doesn't have separate stud for cables, the fuse and the cables are on same stud but with >something< between them. If that something is anything other than copper, say a nut or washer of other material, it could be a high resistance connection.

I prefer separate studs/bolts for wires vs. fuses because then I can unbolt fuse without risking a flying wire coming lose and shorting somewhere.

(Yes, 2/0 is good for well over 200A if individual conductors in free air, for cooling. Just in cable or conduit it's about 200A. But as you say not hot so it's not the problem here.)

I think you have a 6kW inverter. 300A at 24V is 7200W, not enough for inverter inefficiency and 25% headroom to avoid nuisance trips. So shouldn't be run full load continuously. I now add 12% more headroom due to high ripple current.
 
See post #8 for a link to it.

Baomain brand.

That’s my primary suspect in this mystery. ?
Whoops. Totally went past that. Yep. I bet that fuse block has a nasty contact resistance. Massive red flag to me. If OP’s connections are okay otherwise and gets an Eaton/Bussman fuse holder, the problem might go away.
 
Whoops. Totally went past that. Yep. I bet that fuse block has a nasty contact resistance. Massive red flag to me. If OP’s connections are okay otherwise and gets an Eaton/Bussman fuse holder, the problem might go away.

Ahh, but what does that fuse block have to do with contact resistance? Only one stud per terminal. Only way to connect a cable is to stack fuse and cable on same stud. Could have done that with a bolt, no block at all. All that should matter is having terminal make good contact to fuse.
 
If you have a Flooded Lead Acid Battery, your ANL fuse should be OK. You do need to make sure the fuse holder and fuse are ABYC rated for primary battery. THere’s plenty of cheaper models out there intended for stereo useage to blow at a peak of 200 amps, usually a $5 ANL fuse, compared to a ABYC primary battery fuse which around $25. If your ANL fuse has an S you look at to see if it blows, I doubt its that.

Also, check voltage ratings on the fuse, I’m not sure about ABL, but my Maxi fuses are only rated for 33 volts, so that will be good for a 24 volts system. ANL fuses may not be rated for a 48 volt system. I don’t know what you have.

AIC is a big deal and that’s why you use Class C fuses for lithium batteries.
 
Ahh, but what does that fuse block have to do with contact resistance? Only one stud per terminal. Only way to connect a cable is to stack fuse and cable on same stud. Could have done that with a bolt, no block at all. All that should matter is having terminal make good contact to fuse.
Fair point. Hopefully that brand of block permits him to properly torque-sandwich the direct cable-to-fuse connection.
 
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