Fuse help

[Justintoxicated 10+ year member]

Hi I'm looking for a Large Maxi fuse for my Streetwires Distribution block for a Diamond D5 1200.1

Will a 120 amp fuse be large enough? Too Large? I can't find anything larger than 120 amps....hell I'll be lucky if I can pull that much from my alternator...

Also for the ANL fuse for my battery 0ga run I should just add the fuses I'm using for both amps together and find the closest fuse or higher right?

Thanks,

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[helotaxi 5,000+ posts]

The contacts on any MAXI fuse block I've ever seen are only rated for 80A. If you want to go higher than that, I would switch fuse type to either MIDI or ANL for that amp. Before you go to that trouble, hook it up with only the 80A fuse. I think you'll be suprised.

For your main fuse, you can either add up everything or fuse to the 1/0 wire. 250A or less. Something else you can try (what I'm doing for my 2100HCCA right now in fact) is to not run a fuse on the sub amp and use the correct fuse size for it on the main power wire. I have a 150A fuse in my main fuse holder and no other fuse on the + wire for the 2100.

 

[Justintoxicated 10+ year member]

This is what I am using.

http://www.streetwires.com/products/fusedDistBlock/comboFuseBlock.cfm

I don't see why the block would take any less current than the others. I have found maxi's up to 120 amp.

I won't be replacing this block as it is somewhat permanently mount in my truck and it was not cheap either. If I have to I will sell the amp instead (which is not even here yet!) //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[helotaxi 5,000+ posts]

Someone may make fuses rated at 120A, that doesn't mean that the fuse holder is rated to that.

 

[Justintoxicated 10+ year member]

I understand but the fuse holder is HUGE and I don't see how it would not be rated any less that the other ones on that page (there is no listed rating) that take fuses with way over 120 amp ratings. The fuse blocks that hold other types of fuses are basicaly the same design only they don't use blade fuses. I mean i'ts not that complex of a device it's 2 chunks of nickle plated copper with a fuse in between (same thing for all 3 of them on that page only they use different fuses). What difference does it make what kind of fuse is between the 2 pieces of copper other than the what the fuse is rated at? Correct me if' I'm wrong but I'm not understanding. It's not like it's a tiny maxi you get at autozone, the fuses are quite large, I think it's like 6 inches long total.

Actualy the one I'm using is twice as big as those as it is also connecting a 0ga ground. This is a Large block for 2 runs of 0ga wire, it branches out into 4 4ga grounds and 4 power wires it is quite stout no some POS off ebay.

I guessing the 1200.1 uses a 140 amp fuse but I'm not sure as diamond does not have the specs listed. So will a 120 amp fuse be close enough?

 

[helotaxi 5,000+ posts]

Its not the body of the holder that's the issue. The solid chunk of brass can handle a TON of current. It's the little spring contacts that make the connection with the fuse that are the issue. The spring connection is fairly high resistance and has a small contact patch. The result is a lot of heat generated if you pull too much current through that connection. There is a reason that no reputable company markets a MAXI fuse larger than 80A, the fuse holder contacts can't handle more current than that.

I know what a MAXI fuse is. I use them in my current setup in a Stinger Expert block. Even that block which is a 3# lump of brass has contacts only rated at 80A. ATC fuses are only rated to 40A. If you want bigger you need to step up to a fuse with a screw down wide area connection, not a quick change spring contact.

 

[KaeZoo 10+ year member]

There are some Maxi fuse holders constructed with set screws to clamp the fuse blades.

 

[Justintoxicated 10+ year member]

Oops...I went ahead and ordered 120 amp maxi fuses to use with my block...

Should I instead order some 80 amp fuses and just live with them blowing every now and then? (I may be able to change my order.)

I can not find what the max rating on my block is...The contacts appear to be gold plated and are extremely tight holding the fuse, there’s not allot of space or spring action going on with them. They are pretty much pressed against the heavy copper block when the fuse is inserted. Yea these blocks are real heavy!

Also my Current ANL Primary fuse is rated @ 150 amps...I guess typicaly this should be ok? or should I step it up to a 200 amp fuse?

I emailed street wires and asked what the largesgt maxi I can use is...If they tell me $80 amps which of the holders above would you recommend? I think the screws hole are in the same places...You see I screwed this thing into my back wall on my truck, and decided I will never mount anything like that again...I think I paid $90 for this block last year so I will be taking a huge $90 loss to solve this problem....

So the only thing I can replace this block with is one of the others with the same type above…

 

[helotaxi 5,000+ posts]

Unless you just wang on it all the time, I think you will be suprised to find that an 80A fuse will do just fine.

As far as the MAXI holder with set screws, if it doesn't have washers to increase the contact area (and there's really no way for that to work with a MAXI fuse), I wouldn't consider it any better than a regular spring clip MAXI holder and a lot less convenient.

 

[Justintoxicated 10+ year member]

Unless you just wang on it all the time, I think you will be suprised to find that an 80A fuse will do just fine.
As far as the MAXI holder with set screws, if it doesn't have washers to increase the contact area (and there's really no way for that to work with a MAXI fuse), I wouldn't consider it any better than a regular spring clip MAXI holder and a lot less convenient.

Ok here is the response I recieved from Streetwires.

"If you have a 120 amp MAXI fuse that will fit then you should have no

problem with the distribution block."

When I look at the holder the gold plated spring type contacts (one on each side) make pretty decent contact with the fuse, probably 80% or more of the contact tabs of the fuse are in contact with the large, long, flat spring tabs. Also the spring contact itself seems to press against the fuse block but I can't verify this for sure. Guess thats the difference between a $60-80 distro block and some crap off ebay?

I think I'm going to run the 120 amp maxi fuse.

I'm thinking to just run the 150 amp ANL primary fuse off the battery as well, unless someone recomends I change it for sure. If it pops I will replace it with a 200 amp fuse.

Thanks for your help and concern, and for clarifying why there could be an issue with such a high amp maxi fuse.