Are you using fuse in battery harness? What type?

[meelis11]

Hi,
I made my serial harnes with inline blade fuse holder and using 30A fuse. Peak draw is 28A so it does not blow. But it gets warm when riding fast (around 20A continuous) because wire gauge should be fatter - at least 14 gauge is fatter than wire in fuse holder, probably 16 or someting.

Do you use fuse in your harness to make things little more safer or not. I should save connectors when connecting packs wrong or something. I have fried some XT60 connectors when connecting packs to serial and parallel same time That was reason I put fuse to my harness.

What type of fuse/fuse holder is best/better? Seems that blade type is not so good for higher continuous amps. Blade fuse has some burn/spartk marks and I lost power today and did head sparking - fuse did not make good connection. Took it out and turned it other way to hopefully make better connection with fuse holder (swapped fuse legs) and so far it is working.

Meelis

 

[Joe Perez]

I run a 30A automotive blade fuse in mine, pulling 25A continuous. No problems at all. The fuse holder is just one I picked up at Frys Parts Express, nothing fancy.

 

[icecube57]

I used to use AGU fuses in my harnesses but after having them explode when they blow leaving you to pick shards of glass out your fuse holder not to mention the fuse ends caps being stuck in the holder I use Mini ANL now. Ive also had good luck with Maxi Fuses but only with a good fuse holder. Or if you are skilled solder spade connectors with a short lenth of wire. This will be 1 time use but it will ensure a solid connection. With that setup I always had a spare that I could swap if it blew then I went home and salvage the wire and connector and throw away the fuse and put it on a new one and then this becomes my backup directly to the blades for a solid connection because the Maxi Fuse holders and ATC fuse holders tend to melt under extended high amp loads leaving you unable to open the holder and or remove the fuse.

 

[bee]

I ordered an ANL fuse & holder, haven't installed it yet but it seems like the best choice for high amp e-bike stuff:
http://www.ebay.com/bhp/anl-fuse

 

[Joe Perez]

So I went and looked through some order history. This is the exact fuseholder which I have on my big bike, which runs 52v at 25A: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=070-675

In it, I am running this exact fuse: http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=071-380


I put 30A Anderson Powerpole connectors on both pigtails of the fuseholder, and simply inserted it inline with the battery. (I'm using a Cell-Man battery, which came with 30A Andersons already, so the fuseholder literally just plugged right in.) I carry a spare pack of fuses with me inside the battery bag, however I have never needed one. I've been running this setup for about a year and a half, and I have not had any problems at all with the fuses failing.

This would be in contrast to the internal 5x20 glass fuses which my previous battery (a bottle battery from Amped) used, which melted or exploded about once a week on average.

 

[alsmith]

Hi,
I made my serial harnes with inline blade fuse holder and using 30A fuse. Peak draw is 28A so it does not blow. But it gets warm when riding fast (around 20A continuous) because wire gauge should be fatter - at least 14 gauge is fatter than wire in fuse holder, probably 16 or someting.


Meelis

Don't do that!

A bigger gauge number is a smaller diameter wire = less current carrying capacity.



I take it your gauges are AWG? 14G is ok for 32A chassis wiring, 12G 31A, 11G 47A, 10G 55A, 9G 64A etc........
Power transmission wiring is much lower ratings.
If you change to 16G the wires and insulation would probably burn before the fuse blows.

So you should be ok, I'd probably go to at least 12 gauge for safety- you want the fuse to blow .

 

[meelis11]

Hi,
I made my serial harnes with inline blade fuse holder and using 30A fuse. Peak draw is 28A so it does not blow. But it gets warm when riding fast (around 20A continuous) because wire gauge should be fatter - at least 14 gauge is fatter than wire in fuse holder, probably 16 or someting.


Meelis

Don't do that!

A bigger gauge number is a smaller diameter wire = less current carrying capacity.



I take it your gauges are AWG? 14G is ok for 32A chassis wiring, 12G 31A, 11G 47A, 10G 55A, 9G 64A etc........
Power transmission wiring is much lower ratings.
If you change to 16G the wires and insulation would probably burn before the fuse blows.

So you should be ok, I'd probably go to at least 12 gauge for safety- you want the fuse to blow .

My text was misleading - this fuse folder I have right now, has thinner wires (thinner than 14AWG, maybe it is 16AWG? insulation does not have rating printed to it) than my wiring harness, which is 12AWG. My plan is to change it so it is also 12AWG like other harness wires.

What chassis wiring means? Dont we use wires for power transmission?

 

[NeilP]

nope..no fuse...started off with 70 amp big blades..went to 80 and 90's kept blowing the buggers and melting the fuse holders. Gone to home made fusible link soldered in now/. probably good for about 200 amps.

 

[alsmith]

My text was misleading - this fuse folder I have right now, has thinner wires (thinner than 14AWG, maybe it is 16AWG? insulation does not have rating printed to it) than my wiring harness, which is 12AWG. My plan is to change it so it is also 12AWG like other harness wires.

What chassis wiring means? Dont we use wires for power transmission?

Chassis wiring is like car wiring, bike wiring etc. kind of user stuff. Transmission is like those wires that scar the coumtryside-they are always on at full rate and a bit longer that the wires we use. The derating for that application for 14awg is under 6 Amps, 12awg is 9A and you need to go to 7 awg to get 30A.

 

[meelis11]

My text was misleading - this fuse folder I have right now, has thinner wires (thinner than 14AWG, maybe it is 16AWG? insulation does not have rating printed to it) than my wiring harness, which is 12AWG. My plan is to change it so it is also 12AWG like other harness wires.

What chassis wiring means? Dont we use wires for power transmission?

Chassis wiring is like car wiring, bike wiring etc. kind of user stuff. Transmission is like those wires that scar the coumtryside-they are always on at full rate and a bit longer that the wires we use. The derating for that application for 14awg is under 6 Amps, 12awg is 9A and you need to go to 7 awg to get 30A.

Your values seems really low/conservative - maybe these values are for solid copper wire used in home wiring (=power transmission?). Super-fine stranded wire can be used for much more amps. 12AWG stranded should be plenty for 30-40A continuous. Probably 14AWG should be ok for 30A max too.

 

[Joe Perez]

Your values seems really low/conservative -

There are a number of different ways to spec current limits for cabling, and stranded v. solid actually doesn't have anything to do with it. The AWG ratings for stranded vs. solid make the two equivalent in terms of cross-sectional conductor area.

Depending on the application, a chart may be assuming individual wires in free space, or jacketed cable, or bundled wiring in conduit. These all have different formulas. Different applications also rate wiring at different temperatures; typically 60°C for household AC wiring, but industrial cabling might be rated at 75°C or 100°C. And different bodies apply different rules as to what "acceptable" loss is. The NEC has one set of opinions, a manufacturer of industrial robotics might have another, etc. And, of course, the LENGTH of the conductor matters hugely. When I'm doing prototype stuff in the lab at work, I might use a piece of 30 AWG bus wire in a circuit that's going to have 10 amps going through it, and I know I can get away with this because the wire is only 2cm long.


Long story short: There is no one, single formula that you can use to say "The maximum current for an X AWG wire is Y amps."

 

[icecube57]

When you start getting into teflon and silicone wiring the ratings get rather retarded. Meaning they can carry alot of amps not because the wire is better but the Insulation is rated at higher temperatures 200C+ I prefer silicon cause the jacket is thick and takes a ton of mechanical stress and heat before it starts to degrade Teflon tends to be stiffer and lower strand count the jacket is thin on the lower gauge but stands up to heat pretty damn well. The PVC shit that these fuse holders come with is garbage. They tend to have higher (thinner) gauge wire and a very thick insulation. But the insulation isnt that good 80C usually. So when the amps start flowing they tend to melt. Next thing you know you have twizzlers pull and peel. and hope to god they didnt melt and fuse together to where the conduit shorts.

 

[alsmith]

Yep, what is safe is variable depending on the application it's better for less experienced to have a rule of thumb that errs on the cautious side - you can't know the application and all the variables. The table is reasonable advice.

 

[friendly1uk]

You can solder a nice gauge wire straight on to the fuse's terminal blades. No need to buy a holder. Just shrink wrap. You might be surprised just how compact and cheap this method is.

If my load was 15amps I would fuse my pack at 20amps with a fuse in a fuse holder. Then add a 30 amp fusible link (constructed as above) to each of the individual bricks within my pack. The size difference is for discrimination. If there is a motor or controller fault, you know it is the 20 amp exchangeable fuse that will blow. The 30s only blow in the event of unthinkable circumstances not worth wasting any money and space on.

Many won't realise a 20 amp thermal fuse doesn't actually blow at 20 amps. It is to protect a 20 amp circuit. At 19.9 amp it is not sat there white hot about to vapourise. To actually pop one might take 30 amps. You can't run it between 20 and 30 though as it would be too hot.

My lill frog box came with a 20 amp glass fuse.

 

[biohazardman]

I now have a unit with the blade fuse Like Joe's picture. The wire is probly 12Ga and I run a 30A 12V ATC auto blade fuse with 66V on my BMC V2. I have the controller programmed for 50A phase and 30A battery. I have blown the fuse twice in three years going up a hill without pedaling on a hot day. My first fuse holder had thinner wires, expect it was like yours, failed and got crispy after some months. Upgraded to one with the thicker wires and never had another problem.

 

[matterrr]

I've had success with these parts:

Fuse holder
http://www.digikey.com/product-detail/en/178.6152.0001/F5194-ND/2515821

Fuse
http://www.digikey.com/product-detail/en/166.7000.5302/F5168-ND/2515905

Most automotive fuses you find will be rated for 32 volts. When the fuse blows, there could be arcing across the fuse terminals which can further damage your components. These fuses are rated for 80 volts and have arc-quenching material (sand, I think) that melts at high temperatures to insulate the fuse terminals. The fuse holder is also rated for 80 volts.

 

[bee]

steveo recently pointed out to me the risk of arcing at a high voltage.

I'm thinking of soldering one of these inline with my battery:
http://www.ebay.ca/itm/Silver-Tone-Metal-Bolted-Fast-Acting-Fuse-80A-380V-AC-SYU-RGS11-/230914580520?pt=LH_DefaultDomain_0&hash=item35c394e028&_uhb=1

Opinions?

 

[icecube57]

Seems like a winner and a good price also.

 

[alsmith]

steveo recently pointed out to me the risk of arcing at a high voltage.

I'm thinking of soldering one of these inline with my battery:
http://www.ebay.ca/itm/Silver-Tone-Metal-Bolted-Fast-Acting-Fuse-80A-380V-AC-SYU-RGS11-/230914580520?pt=LH_DefaultDomain_0&hash=item35c394e028&_uhb=1

Opinions?

Are they self resetting or blow once? I'm not so sure soldering in a blow once fuse is good for replacement if it blows- can't do it 10 miles from home easily whereas if bolted all it takes is a spanner which we all carry in the toolkits we take with us. Or go home to get.

 

[ricklearned]

steveo recently pointed out to me the risk of arcing at a high voltage.

I'm thinking of soldering one of these inline with my battery:
http://www.ebay.ca/itm/Silver-Tone-Metal-Bolted-Fast-Acting-Fuse-80A-380V-AC-SYU-RGS11-/230914580520?pt=LH_DefaultDomain_0&hash=item35c394e028&_uhb=1

Opinions?

I think that fuse is rated for AC. It might not perform as expected on DC.

 

[ev tocak]

[quoteHi,
I made my serial harnes with inline blade fuse holder and using 30A fuse. Peak draw is 28A so it does not blow. But it gets warm when riding fast (around 20A continuous) because wire gauge should be fatter - at least 14 gauge is fatter than wire in fuse holder, probably 16 or someting.][/quote]

http://www.ebay.com/itm/30AMP-30A-4PCS-Car-AGU-Glass-Fuse-Gold-Plated-For-Car-Audio-/120924838557?pt=AU_Car_Parts_Accessories&hash=item1c27ae9a9d&vxp=mtr

you can solder conductors onto fuse terminals and shrinkwrap them leaving portion of glass visible for inspection +they are fast blow* and cheap to replace .

 

[docnjoj]

I just had a "fuse experience" this afternoon. I was rewiring my electrics and I managed to reverse polarity from the battery through the D/C 36/12 volt converter. Bam! The cap in the converter blew sky high, like a gunshot with smoke. Wow! I reversed polarity to correct and plugged in a new 12 volt converter (I have a few of them) and nothing. So I checked the 30 amp auto fuse and, low and behold, it was blown. Saved my controller and Smart Switch. Definitely a reason for a fuse! First time in 10 years I blew one. Lucky for my bike and me!
otherDoc