Class T fuse holder termination - I think I screwed up.

[SparkyJJO]

A long while ago I bought my 250A Class T fuses and holders from shunts.com. Good price and actually had them in stock at the time too.

But... I goofed.



Bare wire termination. Somehow, I don't think that I should be sticking my fine strand welding wire in there and cranking the screw down, right?

Meaning, I need to either use a ferrule (which 2/0 ferrules and crimpers are expensive), or buy new fuse holders with lug terminations, right?

Just double checking before I go blow another $100 on a pair of fuse holders

 

[ricardocello]

I’d use copper ferrules, but i would also thermally image the connections while running like 200A through it to be sure.

https://www.amazon.com/XL-Uninsulated-Wire-Ferrules-Copper/dp/B0B7YTVTHP

Every milliohm counts….

It’s a round hole, so either use a hex crimp or no crimp, just torque the hell out of the terminal.
Square crimp in a round hole probably not a great idea.

 

[AntronX]

buy new fuse holders with lug terminations, right?

That would be ideal solution.

I don't think that I should be sticking my fine strand welding wire in there and cranking the screw down, right?

If welding wire is large enough then you can get away with it. Screw contact point is smooth in those type of terminals and should not cut wire strands.

 

[hwy17]

Yeah I would change to a bolt lug holder.

 

[AntronX]

Meaning, I need to either use a ferrule

Don't

 

[SparkyJJO]

Anyone want some bare wire termination class T holders for cheap?

 

[robbob2112]

Another possible idea is if you got some copper flashing and cut to width then wrap the strands once before inserting

https://www.amazon.com/Copper-Flashing-99-95-Pure-Contractors/dp/B0CNSS8KXQ/

This would work to protect the strands, but you would need to check for heating at 200amps afterward to make sure it isn't heating up.

This is the same thing as using a bare copper ferrule but allows the wire to squish more.

 

[ricardocello]

Anyone want some bare wire termination class T holders for cheap?

No, thanks!
But would you buy from shunts.com again? I’m looking for reliable no-fuss vendors.

 

[SparkyJJO]

Maybe. Not a bad idea. I've done my share of odd fixes before. But at 200A with LFP batteries I really don't want to make something blow up and be the next guy up in smoke. I just bit the bullet and bought two Blue Sea 5502 holders.

I asked Shunts.com if I could buy just holders from them. Their response was yes, at about $25 each, but I had to buy a minimum of $500 worth

 

[SparkyJJO]

No, thanks!
But would you buy from shunts.com again? I’m looking for reliable no-fuss vendors.

Yeah I would, just make sure to get the right holder the first time The one I got is VERY solid otherwise. They aren't too helpful if you want just a fuse or just a holder though.

 

[glandpuck]

A long while ago I bought my 250A Class T fuses and holders from shunts.com. Good price and actually had them in stock at the time too.

But... I goofed.

View attachment 215329

Bare wire termination. Somehow, I don't think that I should be sticking my fine strand welding wire in there and cranking the screw down, right?

Meaning, I need to either use a ferrule (which 2/0 ferrules and crimpers are expensive), or buy new fuse holders with lug terminations, right?

Just double checking before I go blow another $100 on a pair of fuse holders

Please see photo. You are supposed to crimp a terminal lug on the battery wire.

 

[JRH]

Anyone want some bare wire termination class T holders for cheap?

Blue seas holders are not as high now days, if they will fit the fuses you have .

 

[glandpuck]

A long while ago I bought my 250A Class T fuses and holders from shunts.com. Good price and actually had them in stock at the time too.

But... I goofed.

View attachment 215329

Bare wire termination. Somehow, I don't think that I should be sticking my fine strand welding wire in there and cranking the screw down, right?

Meaning, I need to either use a ferrule (which 2/0 ferrules and crimpers are expensive), or buy new fuse holders with lug terminations, right?

Just double checking before I go blow another $100 on a pair of fuse holders

Regarding ferrules and 2/0 wires, the ferrules are very thin and are one time use just to keep the fine strands from being outside of the connection and arcing. Just slip it over the wire and it will compress down when tightened.
But you need proper copper lugs to carry the amperage. And a reminder to all: fine stranded welding wire is EPDM rubber coated and kind of meant to be used in environments where the wire is on the floor of a business coming into contact with oils, grease or other shop used compounds in the welding process.

The most appropriate battery wire to use is fine stranded THHN/THHW which will bend and be able to pass through conduits easily.

 

[SparkyJJO]

Blue seas holders are not as high now days, if they will fit the fuses you have .

I have 250A Littelfuse fuses. Same ones that the Blue Sea holders use. Shouldn't be a problem.

Regarding ferrules and 2/0 wires, the ferrules are very thin and are one time use just to keep the fine strands from being outside of the connection and arcing. Just slip it over the wire and it will compress down when tightened.
But you need proper copper lugs to carry the amperage. And a reminder to all: fine stranded welding wire is EPDM rubber coated and kind of meant to be used in environments where the wire is on the floor of a business coming into contact with oils, grease or other shop used compounds in the welding process.

The most appropriate battery wire to use is fine stranded THHN/THHW which will bend and be able to pass through conduits easily.

I've never seen "fine stranded" THHN. That's why so many people use welding wire, is it not?

Please see photo. You are supposed to crimp a terminal lug on the battery wire.

But that's not how the fuse holders I originally bought were designed to work, hence the reason for this thread.

 

[ricardocello]

fine stranded welding wire is EPDM rubber coated

I’ve never tried to put my Class K Welding Cable into conduit. Are people successfully doing that?
Edit: Clarified Class K, wasn’t trying to make a joke.

 

[glandpuck]

https://www.amazon.com/gp/product/B001VJ03LA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1#:~:text=to%20zoom%20in-,Blue%20Sea%20Systems%20Class%20T%20Fuse%20Blocks,-Brand%3A%20Blue%20Sea

This is what should be used. Very secure, stable and allows easy replacement of a blown fuse.

 

[glandpuck]

I’ve never tried to put my Class K into conduit. Are people successfully doing that?

Funny. Fuses and their holders don't go into conduit. Wire goes into conduit.

 

[SparkyJJO]

https://www.amazon.com/gp/product/B001VJ03LA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1#:~:text=to%20zoom%20in-,Blue%20Sea%20Systems%20Class%20T%20Fuse%20Blocks,-Brand%3A%20Blue%20Sea

This is what should be used. Very secure, stable and allows easy replacement of a blown fuse.

Yeah, That's what I bought.

Funny. Fuses and their holders don't go into conduit. Wire goes into conduit.

He wasn't talking about his fuse. Class K is welding wire. There is also Class M. Has to do with how fine the strands are (M is finer and a little more flexible, I think).

 

[robbob2112]

People use welding wire because of bendability and the higher heat rating on the sheath so it has a higher ampacity in free air. And Victron and other vendors recommend it for the DC side of their equipment.

The reduced resistance is minimal especially over the distances we use.

 

[robbob2112]

One more tidbit I found -




And it seems like "Fine stranded" THHN is commonly refered to as battery wire like they use in a car. More strands than standard but not as many as welding wire.


We really need a good resource write up on the various types of wire commonly available with a comparison of their ampacity, heat rating, and common use.