# Where to get fuse holder at reasonable price



## swoozle (Nov 13, 2011)

If you are so inclined, they are pretty easy to make. Sourcing the plastic may be the challenging part. There's a west coast chain (TAP Plastics) with a local store that I was able to buy cheap excess at, but another option is buying phenolic sheet from some place like McMaster Carr. My materials ran less than $10; the phenolic option would probably put it in the $30 range.







White plastic primary base, black plastic spacers and secondary bases for the actual fuse bolts. Fuse lugs bolted directly to cable lugs. Fasteners from the local hardware.
The foam is to keep the cover from rattling. The aluminum square tube base isn't part of it, that's just where it worked out to mount easily.


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## sabahtom (Mar 1, 2011)

Hi Swoozle

You've done a slick job there. I'm not in the USA, so I may have to use a wall socket enclosure and a chunk of kitchen cutting board as the white plastic base. Not pretty but I guess it'll work.

Any considerations for melting point of the plastic or protection from arcing?

I've also seen it suggested that two fuses should be used in the main circuit to ensure at least one will blow. Do many EV's have that?


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## Duncan (Dec 8, 2008)

Hi Guys

Why mess with plastic?
I used MDF - just give it a nice coat of varnish or paint to protect it from water


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## swoozle (Nov 13, 2011)

sabahtom said:


> Any considerations for melting point of the plastic or protection from arcing?
> 
> I've also seen it suggested that two fuses should be used in the main circuit to ensure at least one will blow. Do many EV's have that?


That's actually a good question about melting. Certainly the fuse shouldn't get that hot in normal use, but I'm not familiar with how hot they get in a failure situation before they blow. Maybe someone with experience can weigh in. 
Temp resistance would be one advantage of going with phenolic. 

It's easy enough to size the pieces to eliminate any arcing concern. A couple tenths of an inch well give you well more than enough standoff through air. 

I haven't heard the multi fuse suggestion. I only have one. Why would one not blow?


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## sabahtom (Mar 1, 2011)

*Redundant fuses*

I saw it on a US ev manufacturer website a day or two ago, can't remember which one. They also sell fuses so they may be trying to double their sales 

Their theory was that fuses of the same rating may take slightly longer to blow than advertised, so if two are used in series then you've got a better chance of staying below the allowable current. I guess by that logic three would be better than two.


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## sabahtom (Mar 1, 2011)

Duncan said:


> Hi Guys
> 
> Why mess with plastic?
> I used MDF - just give it a nice coat of varnish or paint to protect it from water


Hi Duncan

I haven't done a fuse holder before, but the ones I see on the net are glass or high temp plastic. I was thinking of plywood but ditched the idea because it's flammable. Wouldn't that be an issue?


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## major (Apr 4, 2008)

The fuse is one of those things that adds no performance but consumes space and cost money. But it is a critical safety item which you must have. So don't skimp. Use the proper fuse and proper fuse holder properly installed. Period.

Sometimes it is advisable to use multiple fuses in the main battery circuit. Most often this is due to multiple battery boxes. Each energy storage source should be fused to protect that portion of the battery and the cables connecting it.

When things are working well, the fuse is often forgotten. It can sit hidden and not inspected for years. So be prudent with the installation. Do not use a wooden base or some crap like that. Get some moisture and rot and you'll have a loose fuse bouncing around.

Do it right and it will be there to save your butt should you need it. Yeah, you're a careful driver, but there are thousands of idiots sharing the roads with you.

I've seen one EV burn to the ground. A Lola. And it was not a battery fire or crash on the track. It was an improperly installed fuse


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## Duncan (Dec 8, 2008)

Hi Major
I like wood - it's non conductive, cheap strong, not very inflammable

It can rot - but not if it is well varnished 
After all they make boats out of it!

You don't want to use wood somewhere tucked away out of sight and wet
But then I don't want my fuse somewhere like that


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## Ziggythewiz (May 16, 2010)

*Re: Redundant fuses*



sabahtom said:


> Their theory was that fuses of the same rating may take slightly longer to blow than advertised, so if two are used in series then you've got a better chance of staying below the allowable current.


That's just ill-informed logic. They don't blow quickly at their sticker rating because that's how they're designed. A 400A fuse might blow after an hour over 400A, but 1 second at 1,000 amps. The key is to know what you're getting and spec it appropriately. For most EV fuses that means sizing it a little over average usage, not peak.

If you use 2 or 3 oversized fuses they'll all take an hour to blow.


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## JRP3 (Mar 7, 2008)

Duncan said:


> Hi Guys
> 
> Why mess with plastic?
> I used MDF - just give it a nice coat of varnish or paint to protect it from water


Why mess with MDF and paint?


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## Zappo (Sep 1, 2011)

Duncan said:


> I like wood - it's non conductive, cheap strong, not very inflammable


Hi Duncan,

Not saying it would happen at lower voltages but this reminded me of a Jacobs Ladder I made with an ignition transformer years ago. It was for a vocational school open house so I made the sides out of plexiglass to keep fingers out of it. I made the top out of plywood.

It worked great for about an hour. The arc would travel up the rods until almost to the top and then start over at the bottom, just like in the old horror movies. All of a sudden, the arc disappeared. A few seconds later, the plywood started smoking. It turned out that it got a carbon track through one of the inner plies of the plywood. The outside of the plywood looked great. The inside ply was completely black.

It was pretty cool, but I've never trusted wood with electricity since.


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## Ziggythewiz (May 16, 2010)

Hopefully your EV wouldn't have as much arcing as a Jacob's Ladder.


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## sabahtom (Mar 1, 2011)

Most of my driving is on flat roads so I expect to be under 1C (100ah cells, 309v pack), but I live on a hill that is 80m high with lots of sharp bends, meaning low rpm/high amps for about two minutes at a time.

I think this fuse will be the right one?

[h1]COOPER BUSSMANN - 160FEE - FUSE, 160A, 690V, TYPE T [/h1]


Product Information


 FUSE, 160A, 690V, TYPE T
 Voltage Rating V DC: 500V
 Voltage Rating V AC: 690V
 Fuse Current: 160A
 Blow Characteristic: Fast Acting
 Fuse Size Code: FEE
 Fuse Size Metric: 37mm x 94mm
 Fuse Size Imperial: 1.46" x 3.7"
 SVHC: No SVHC (18-Jun-2012)
 Approval Bodies: BS
 Approval Category: UL Recognised
 Body Diameter: 19mm
 Body Length: 46mm
 External Length / Height: 94mm
 Fuse Type Blowing Characteristic: T
 I2t @ 415V: 3700s
 I2t @ 660V: 5700s
 I²t Pre-arcing: 1000
 Power Dissipation Pd: 46W
 Power Dissipation Pd: 46W


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## Ziggythewiz (May 16, 2010)

Looks like it's rated to blow at 500A in 10 seconds, or 600A in 1 second. What's your controller put out?


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## sabahtom (Mar 1, 2011)

Hi Ziggy thanks for the quick reply.

Azure Dynamics is out of business so I haven't been able to nail down exactly which model I've got (I bought it second hand). 

The max motor current is given as either 250 or 280A RMS depending on model 59kw or 78kw. 

Since the controller and motor are a matched set I guess that's the controller max as well.


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## Duncan (Dec 8, 2008)

JRP3 said:


> Why mess with MDF and paint?


Cause I've already got some?

And plastic is either expensive or inflammable or both (for our American cousins -flammable)


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## steven4601 (Nov 11, 2010)

Is there no moderator who monitors shared advise content?

Like not allowing to promote to give advise to start running with sharp pointy things / siscors etc.


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## JRP3 (Mar 7, 2008)

Duncan said:


> And plastic is either expensive or inflammable or both (for our American cousins -flammable)


And wood isn't?


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## Duncan (Dec 8, 2008)

JRP3 said:


> And wood isn't?


If I just take it off my odd-bits shelf - wood is cheap!
Wood is inflammable - but not very - some plastics are a LOT easier to ignite!


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