Do you know if this works with Eaton and Blue Sea fuses? So you can stack two of them in battery terminal?
Searching for: Mega fuse holder that bolts directly to battery terminal
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Do you know if this works with Eaton and Blue Sea fuses? So you can stack two of them in battery terminal?
Vigilant24
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I >think< the fuse holders for these MRBF fuses are common to all brands, but I am not sure.
The dual fuse holder just has an extended tab from the battery that allows two fuses to be put flat on it (rather than just one). Rach fuse can protect a separate circuit, and they aren't stacked or in series (so blowing one won't affect the other fuse).
There is a picture at this link. I've seen these dual-fuse holders sell for about $16 elsewhere.
https://www.amazon.com/Dual-Termina...se&qid=1684761777&sprefix=mrbf,aps,712&sr=8-8
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Vigilant24
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Yes, getting a multitude of formats/types is a problem, especially if it is for a remote/emergency installation where it might be hard to get replacement bits and flexibility is important.
The Megafuses (of brands I know and trust--Littlefuse, Buss, etc) sell for about $10-$15 each in small quantities. They are cheaper if bought by the bag with an unknown branding from China. The MRBF fuses from brands I know (Buss, etc) cost about $15 each. If no-name brands are okay, this place offers the MRBF fuses for about $5 each. A dual-fuse block complete with two fuses sells for about $20.
https://www.amazon.com/VOZINMOST-Hi...2728&sprefix=mrbf+fuses+eaton,aps,126&sr=8-39
I don't plan on burning through a lot of these (hopefully!), so replacement cost isn't a huge factor for my case.
Vigilant24
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Those .might< work, and they would be cheaper than a purpose-built MRBF fuse holder. Points I'd want to consider:
1) Technical: Would they adequately do the same thing? It would be useful to make sure that the contact area with the fuse is sufficient, if their contact metal is compatible with the fuse material, etc.
2) Legal/liability: If the fuse fails to function and the sharp-eyed inspector sent by the insurance company comes sniffing around for a reason to deny paying a fire claim, I'd like to have complied with the guidance of the fuse manufacturer. (I think this is a very unlikely situation for me, but it may mean a lot to others).
3) Practical: That final positive terminal on the battery pack is some valuable real estate. If the post is physically monopolized by a stand-off insulator with an MRBF on it, then everything else will be in serial with that fuse. That might included lesser loads (e.g. another smaller inverter, DC loads, etc) and also the input from the solar charge controller. I suppose we could stack up additional fuses pagoda-style to protect these smaller loads, but it would get cumbersome and if a fuselower down in the stack gets blown, everything loses connection >and< the whole stack neds to be disassembled to change a lower fuse. Using the standard fuse holders puts just one tab on the battery post (and that tab can host 1 or 2 MRBFs each with its own load) and there's still vacant threaded space remaining on the battery post for future expansion.
Anyway, the standoff insulators might work just fine, I don't know.
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The main issue here is not physically supporting the fuse, but anchoring the ends of the often massively thick and heavy cables going to the fuse.
To change the fuse, you just remove a couple of nuts, swap out the fuse then back into operation.
The cartridge fuse itself is designed to contain all the fire and explosive fury within, no need for any additional enclosure to protect nearby parts.
These standoff insulators are parts DESIGNED for high voltage heavy duty electrical applications. That is what they are for. They meet all the statutory requirements for electrical insulation and flammability, so in that respect are at least equal to a purpose built fuse holder.
The theory of using electrical lugs, is that the bolt must not carry the current, it merely provides clamping force to compress the copper parts and hold them very securely together. High tensile steel bolts are ideal for that function. The electrical current then flows directly between the copper parts.
I would not bolt one end of a fuse directly onto one of the battery terminals, any movement applies stresses the parts were not designed for.
Much better to bolt the standoff insulators to a rigid part of the metal battery frame, in a readily accessible location, and use a short length of flexible wiring between the last battery terminal and the fuse. Its also then possible to locate the fuse where metal tools are less likely to cause any shorts to ground when replacing the fuse.
Its not rocket science, but any electrical inspector will be looking for obvious points of danger, or potential failure. If its a well thought out, neat, and practical installation, the inspector is more likely to appreciate the thought and effort that went into it.
To change the fuse, you just remove a couple of nuts, swap out the fuse then back into operation.
The cartridge fuse itself is designed to contain all the fire and explosive fury within, no need for any additional enclosure to protect nearby parts.
These standoff insulators are parts DESIGNED for high voltage heavy duty electrical applications. That is what they are for. They meet all the statutory requirements for electrical insulation and flammability, so in that respect are at least equal to a purpose built fuse holder.
The theory of using electrical lugs, is that the bolt must not carry the current, it merely provides clamping force to compress the copper parts and hold them very securely together. High tensile steel bolts are ideal for that function. The electrical current then flows directly between the copper parts.
I would not bolt one end of a fuse directly onto one of the battery terminals, any movement applies stresses the parts were not designed for.
Much better to bolt the standoff insulators to a rigid part of the metal battery frame, in a readily accessible location, and use a short length of flexible wiring between the last battery terminal and the fuse. Its also then possible to locate the fuse where metal tools are less likely to cause any shorts to ground when replacing the fuse.
Its not rocket science, but any electrical inspector will be looking for obvious points of danger, or potential failure. If its a well thought out, neat, and practical installation, the inspector is more likely to appreciate the thought and effort that went into it.
Why not use a Bussmann marine fuse holder? I bolt those to a battery bank busbar and connect the individual batteries to the busbar through these fuses. I believe Deep Sea may stock these. I have bought my fuse holders through AliExpress but the fuses are genuine Bussmann.
