Sandwich a solid plate of polymer under the bolt head. It wouldn't need to be very thick to provide absolute isolation.
I would just use T-Nuts like these.
DIY Fuse Holders and Distribution Busbars
- Thread starter ArthurEld
- Start date
I would just use T-Nuts like these.
ArthurEld
Solar Wizard
I could paint those T nuts in the stuff made for insulating tools and just use it for a terminal stud or the base for a busbar or fuse.
Or Flex Seal it ?
Last edited:
ArthurEld
Solar Wizard
Guys, here's my first attempt with a 100A class T fuse.
Since I moved my BMS the fuse is awfully close to the lug.
There's a T nut in the wood block. I will make terminal lugs out of screw down T nuts for the fuse and the BMS lugs.
My main positive cable will connect to the left side of the fuse.
I plan to put a piece of hose over the BMS lug.
But the class T fuse has way too much contact exposed. I have to come up with a cover for the fuse that won't melt or catch fire.
I will appreciate any suggestions. I have to do 4 of these so I want it safe and decent looking
Since I moved my BMS the fuse is awfully close to the lug.
There's a T nut in the wood block. I will make terminal lugs out of screw down T nuts for the fuse and the BMS lugs.
My main positive cable will connect to the left side of the fuse.
I plan to put a piece of hose over the BMS lug.
But the class T fuse has way too much contact exposed. I have to come up with a cover for the fuse that won't melt or catch fire.
I will appreciate any suggestions. I have to do 4 of these so I want it safe and decent looking
ArthurEld
Solar Wizard
I'm still hacking away. I put on the T nuts. And moved the BMS terminal farther away from the fuse.
I will switch the bolts for studs.
For temporary safety I added a piece of clear hose split so I could get it over.
And a piece of cardboard corner. Makes me feel a little better. I doubt the fuse will catch it on fire but I will come up with a better idea.
I will switch the bolts for studs.
For temporary safety I added a piece of clear hose split so I could get it over.
And a piece of cardboard corner. Makes me feel a little better. I doubt the fuse will catch it on fire but I will come up with a better idea.
One comment about mounting terminal bolt to flammable material. If those nuts ever get loose, the contact resistance is going to increase and the connection is going to get hot. Since this is the primary wiring to the battery, you could easily be seeing > 100A passing through those connections.
I would use proper surface or bulkhead mount terminal blocks that are made out materials rated to handle the temperature.
Something like this if you want to pass it through a wall.
Or something like this is you just want to bolt it to a surface (no penetration of wire through the surface).
These will work with conductive or nonconductive surfaces.
ArthurEld
Solar Wizard
Well, I like your T nut suggestion. And thanks for the reminder.
I guess it is possible that screw could get red hot.
I will look for some non flammable material to mount the t nuts to.
It is a 100A fuse and I don't plan to go over 50A
I guess it is possible that screw could get red hot.
I will look for some non flammable material to mount the t nuts to.
It is a 100A fuse and I don't plan to go over 50A
Problem is if the hardware loosens up. For a mobile application you definitely need to use some kind of locking hardware. I like star washers in general. Not sure if they are a good idea for copper bus bars.
For a residential application, I would use nylon locknuts. Don't forget, nylon locknuts loose holding power each time you loosen and retighten them. So hold off on using them until the system is fully commissioned.
This is what a loose connection can do. Think about how many watts you could be pushing through that termination.
Pic is from an AC panel which is higher voltage and lower amps. Low voltage DC wiring pushing a lot of amps is more likely to overheat.
Pic is from an AC panel which is higher voltage and lower amps. Low voltage DC wiring pushing a lot of amps is more likely to overheat.
ArthurEld
Solar Wizard
The cardboard and plastic hose are just for when it's not in use.
I will make my terminal blocks to be as safe as the ones from Amazon but I don't think they'll help much for something like that.
The plywood on my battery would be difficult to catch on fire but there's no sense pushing my luck.
I will make my terminal blocks to be as safe as the ones from Amazon but I don't think they'll help much for something like that.
The plywood on my battery would be difficult to catch on fire but there's no sense pushing my luck.
That is what I was thinking off. They are not very expensive. Would hate to burn down your power shed (or house if you put this inside the house).
To coin a phrase "Fences may make good neighbors, but outbuildings make for longer marriages." I have a blacksmith friend who would have no problem with that sentiment.
Roswell Bob
Solar Enthusiast
Try Glastic
Roswell Bob
Solar Enthusiast
ArthurEld
Solar Wizard
Yea, I have come to the conclusion that I need something like that. Hedges posted some isolating standoffs like that.
I didn't think I needed to isolate the base since it's attached to wood. But it is probably considered sloppy to have everything electrified including the screws going into the wood.
The isolating standoffs would also isolate the heat.
DIY often comes with the risk of doing something dangerous because of ignorance.
I don't think what I was planning to do would ever cause a fire. But I can see that it is the wrong way to do it.
I am not impressed by the terminal studs sold on Amazon. Some are better than others I'm sure but the plastic base looks weak and it looks like the plastic might catch on fire. My wood probably wouldn't catch on fire but it might with melted burning plastic all over it.
Last edited:
ArthurEld
Solar Wizard
This is looks pretty good - https://www.altestore.com/store/enc...ocks/110a-class-t-fuse-and-fuse-holder-p2119/
Looks like my Blue Sea Class T holder. About the same price too.
ArthurEld
Solar Wizard
I had trouble finding that size. I think you are right that it is Blue Sea. It says that it comes with the fuse too for that price.
I ordered 4
I ordered 4
Maybe not Blue Sea then. My holder alone was $42. Fuses were not included.
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,660
I got this fuse holder, but difficult to remove cover without breaking plastic:
www.bluesea.com
Consider this one instead, has clips to hold cover:
www.bluesea.com
Alternatively, there are Class T holders one piece or two that can be spaced to fit any size. Cover not included.
Class T Fuse Block with Insulating Cover - 225 to 400A - Blue Sea Systems
Allows use of Class T fuses for high speed circuit protection of electronic equipment and inverters.
www.bluesea.com
Consider this one instead, has clips to hold cover:
Class T Fuse Block with Insulating Cover - 225 to 400A - Blue Sea Systems
Allows use of Class T fuses for high speed circuit protection of electronic equipment and inverters.
www.bluesea.com
Alternatively, there are Class T holders one piece or two that can be spaced to fit any size. Cover not included.
I got this fuse holder, but difficult to remove cover without breaking plastic:
Class T Fuse Block with Insulating Cover - 225 to 400A - Blue Sea Systems
Allows use of Class T fuses for high speed circuit protection of electronic equipment and inverters.
Consider this one instead, has clips to hold cover:
Class T Fuse Block with Insulating Cover - 225 to 400A - Blue Sea Systems
Allows use of Class T fuses for high speed circuit protection of electronic equipment and inverters.
Alternatively, there are Class T holders one piece or two that can be spaced to fit any size. Cover not included.
With what I know now, I would absolutely go with the fuse holder with clips. While I haven't broken my cover (the first link), it sure is a PITA to remove and almost as difficult to install.
Similar threads
- Sticky
