[want33s]

To stop confusion in the other thread lets talk about this crap here.

My winch is protected by ANL gold fuses.
When I purchased them I was told they have an advertised load rating and a much lower dead short value.
I don't understand how this works but have taken the sellers word for it.
After posting about these fuses a few people have said it is impossible, maybe it is maybe it isn't I don't know.

I sent a question to the seller on Ebay (Derek Bester Automotive Engineer)....

want33s wrote:

"Hi Derek, I have heard these fuses can handle a 200A load but will blow a lot lower if a dead short is present EG:30-40A. Is this correct? Thanks, Jas."

He replied with....

Derek Bester Automotive Engineer wrote:

"Yes that is correct."

Ebay store...
http://myworld.ebay.com.au/4145derek?ss ... TQ:AU:1181

[Bugsta]

I'm having lunch with my dad today who is a retired mechanic and did a lot of auto electrical to. I'll ask his opinion on this, but it sounds like rubbish to me.

[squibby]

Good research thanks. I personally view my winch as an emergency recovery device. So fusing it is a hinderence if the fuse blows during an emergency recovery mission. I'd rather bare the hot 35mm cables and a bit of overcurrent for a few seconds so long as it pulls me out of the bog I'm stuck in.

On the other hand I wouldn't knock anyone who decides they want to fit them. Each to their own.

I do note that in event of a frontal accident it is possible that a winch cable may get frayed/earthed. So whats the go with those cables from the winch solenoid to the winch motor? Are any of them 12V live at all times? or only live under operation of the winch? If so I reckon I might be tempted to fuse.

[shep]

has jas, how does the fuse handle winch loads? my 6500 can draw over 400amp

[Reubs]

want33s wrote:

want33s wrote:

"Hi Derek, I have heard these fuses can handle a 200A load but will blow a lot lower if a dead short is present EG:30-40A. Is this correct? Thanks, Jas."

He replied with....

Derek Bester Automotive Engineer wrote:

"Yes that is correct."

Ebay store...
http://myworld.ebay.com.au/4145derek?ss ... TQ:AU:1181

Electricity doesn't work like that. I = V/R That is, the current across a dead short will always equal the voltage divided by the resistance, limited only by the source = i.e. a cranking battery capable of delivering hundreds of amps. A dead short fed by a car battery will only be 30-40A if there is LOTS of resistance in the wiring or the run of wiring is as long as your street!

What these fuses would actually do is blow faster than a standard fuse, which is why you see interesting fuses powering amps etc instead of regular maxi blade ones.

All fuses (automotive or otherwise) are designed to blow in a particular amount of time proportionate to the current flowing through them. Circuit breakers also perform similarly. Example for a 10A blade fuse, you will be able to pass 15A through it but it might blow in 30 minutes. At 20 amps that fuse might blow in 30 seconds and at 50A that fuse might blow in 0.5 seconds. At 200A that fuse might blow in 1/20th of a second. A fuse which is designated as fast acting might have a similar curve, but might blow in half the time for each given current value.

[want33s]

shep wrote:

has jas, how does the fuse handle winch loads? my 6500 can draw over 400amp

My winch is a chinese 9500lb unit.
I had a ceramic 400A in mine and it blew when the winch field shorted out.
I couldn't get another 400A fuse at the time so replaced it with a 200A gold fuse.
Have done some triple pull winch recoveries on Patrol and cruiser stuck in black swamp mud up to headlights and not blown the 200.

[shep]

want33s wrote:

shep wrote:

has jas, how does the fuse handle winch loads? my 6500 can draw over 400amp

My winch is a chinese 9500lb unit.
I had a ceramic 400A in mine and it blew when the winch field shorted out.
I couldn't get another 400A fuse at the time so replaced it with a 200A gold fuse.
Have done some triple pull winch recoveries on Patrol and cruiser stuck in black swamp mud up to headlights and not blown the 200.

looks like i will be sticking one on each of my cars then

[royce]

squibby wrote:

Good research thanks. I personally view my winch as an emergency recovery device. So fusing it is a hinderence if the fuse blows during an emergency recovery mission. I'd rather bare the hot 35mm cables and a bit of overcurrent for a few seconds so long as it pulls me out of the bog I'm stuck in.

If a fuse is correctly rated and the install is sound it will never blow and never be a hinderance

this is much much better than melted cables and a burning car while you try to winch getting out of a bog cause you didnt try to make life easier for it to begin with.

[squibby]

Ok, I've been talked me into it. I'll fit a 200A very slow blow fuse to my winch and see how I go. The far-fetched stories about cars burning are a bit drama queen to be honest though. My install is sound and freak accident's are unlikely. It's most likely like my winch will grind to a halt and I'll cut the power within a second or two afterwards if I ask too much of it, perhaps slightly warm to the touch cables. I'm more bothered about the fact the winch cables are routed around the front impact zone of my vehicle, so a short circuit is a reasonable possibility.

[Dr_Snapid]

Thanks for making a thread for this. Much better than hijacking old mate's topic which is regrettable.

Reubs has it pretty straight according to my own knowledge and experience. I admit that I am not an auto electrician (or an electrician, either) and I acknowledge that sometimes practice can work differently to theory. But I just cannot see how a fuse can blow at a 'low current short' (or even what a low current short is for that matter) and still support a much higher current draw without blowing.

A few points:
1) If you ask me, from a fuses perspective, a short is just a bloody huge current draw. Any fuse that can handle 400A+ for any useable period of time without melting will brobably not 'fast blow' intil some seriously massive current is drawn.
2) A fuse that can handle more current than the wiring it's in series with is not a fuse. The cable will fuse first. So you really must have a good gap between the current capability of your fuse and your wiring. I would say 70% of your cable's capacity at most. So if you cable can carry 100A then 70A fuse at most. Maybe there is some sort of official standard on this. This is just a guidline I would use.
3) Some have said the fuse protects the wiring. I guess thats true but personally it's the possibility of melted wiring causing much worse outcomes that I worry about (ie car on fire, kids strapped in back seat)

So in relation to a winch.

IF you only use your winch for a matter of minutes at a time, you may be able to draw your 400A peak (the real current will vary with load so will likely average less during a recovery) through a 200A fuse without blowing it. It will warm up but not to the point where it melts, or at least not in the time it takes to finish recovering. So I would still fuse a winch with a lower value fuse(say 200 amp, if your cables are OK for 300A continuous) . Maybe chuck a larger one in for emergeny use if the worst should happen.

[Blakey]

squibby wrote:

Good research thanks. I personally view my winch as an emergency recovery device. So fusing it is a hinderence if the fuse blows during an emergency recovery mission. I'd rather bare the hot 35mm cables and a bit of overcurrent for a few seconds so long as it pulls me out of the bog I'm stuck in.

On the other hand I wouldn't knock anyone who decides they want to fit them. Each to their own.

I do note that in event of a frontal accident it is possible that a winch cable may get frayed/earthed. So whats the go with those cables from the winch solenoid to the winch motor? Are any of them 12V live at all times? or only live under operation of the winch? If so I reckon I might be tempted to fuse.

There will be 12V up to your Winch Relay after that there will only be 12V to the winch when your switch the Relay. UNLESS you are Negatively Switching your winch then you will have 12V potential to the motor.

so you would only short that cable if your relay was crushed unless its negatively switched then the entire cable would be likely to short to negative in a crash as it is live.

either way its still best to Fuse All Cables at or close to the battery as well at to fuse both ends of your battery interconnect as both batteries can feed the fault if they are not. The fuse is there to protect the Cable which in turn protects against Fire. a large battery can easily put out in excess of 800A in a short.

as well at to fuse both ends of your battery interconnect. as both batteries can feed the fault if they are not.

if you want to protect your cable and car from fire in the event of a crash but still have a usable winch free of annoying blowing. you put in larger cable and properly rated fuse to protect the cable that is over what your winch uses at max load. and put in a very fast blowing fuse,

you don't really want a slow blow fuse unless your starting a huge motor, that takes allot of amps to start up. A winch is not a large motor it doesn't require a huge start up current that is greater then the fuse, so they are not needed at all. and will just cause problems in a real fault. as they will keep the fault on longer then what you want it on.

I it takes less then a second at 800-900A for a cable to melt and catch fire in a fault unless its like 90mm² which might be able to handle that for a small amount of time. and some slow blow fuses can take 2-5sec to blow when they are only at 150% rated current

[want33s]

Some reading... No answer but good info nonetheless.

http://bluesea.com/viewresource/95

[Dr_Snapid]

Thanks for the link, it seems to confirm that the behaviour of ANL fuses is different from the bahavior of other fuses. I wonder if that's why the ebay seller said they werent like normal fuses.

[got_bar_work]

Well looking at that I don't know where the guy gets the 40a from
A 200a fuse blows at 320a which makes sense why it didn't blow

[britvit]

squibby wrote:

Ok, I've been talked me into it. I'll fit a 200A very slow blow fuse to my winch and see how I go. The far-fetched stories about cars burning are a bit drama queen to be honest though. My install is sound and freak accident's are unlikely. It's most likely like my winch will grind to a halt and I'll cut the power within a second or two afterwards if I ask too much of it, perhaps slightly warm to the touch cables. I'm more bothered about the fact the winch cables are routed around the front impact zone of my vehicle, so a short circuit is a reasonable possibility.

My car set on fire with unmodified standard wiring - it was a freak accident- they can and do happen.
If the cables on your winch are getting warm they are probably undersized- pvc insulation doesn't like heat, overtime it will get brittle and fail.

[fordem]

So now that we've seen the numbers - can we agree that your eBay seller is misrepresenting the capabilities of the product?

According to the link you've provided, ANL fuses are a delay type fuse, and your 200A ANL fuse will allow 320A for 500 secs - it can't tell the difference between a load draw & a short circuit - all it does is get hot and when it's hot enough to melt, it does, interrupting the current flow - the higher the current draw, the hotter it gets, the sooner it will melt - if it's going to melt with 40A, it will melt with 200A - conversely - if it will withstand 200A it will also withstand 40A.

[Dr_Snapid]

fordem wrote:

So now that we've seen the numbers - can we agree that your eBay seller is misrepresenting the capabilities of the product?

That is my view. Perhaps the seller misunderstands the way it works.

[want33s]

fordem wrote:

So now that we've seen the numbers - can we agree that your eBay seller is misrepresenting the capabilities of the product?

Well, NO. In order to agree that the seller is misrepresenting the product I would need to KNOW otherwise and I don't.
I have already stated I don't understand how it could work and that I'm no auto electrician hence not qualified to make a statement for or against.
Just repeating what my seller told me.

I provided a link to the Ebay store above. Why don't you ask him?

[royce]

Another option is to fit an isolator switch somewhere close to the battery, so you can kill all the power if it all goes to shit, you might already be in fire but it wont get as bad as quickly

[Dr_Snapid]

Your winch can be isolated until you need it anyway

[Mike57]

I found this site had a good explantion as well. http://www.bcae1.com/fuses.htm I must admit to just a quick read of the previous posts so excuse me if I am repeating what may have been stated before. The ANL 200 amp fuse will take more than 8 minutes to blow with 320 amps through it (my reading anyway). That is why you can run a 400 amp winch through it without it blowing. If there was a short circuit then the current flowing will be whatever the battery can deliver governed only by the resistance of the cables. This will be more like 650 amps and so under a short circuit the fuse will blow in a relatively short time. No way will this fuse blow with only 40 amps.

As stated before this is a very slow blow fuse and I have no idea really what the right application would be for such a fuse. You would have to be very careful about dimensioning all the cables and connections to handle the potential current before this fuse blew and then risk cooking your battery in the process if you made the wrong fuse selection. Might be best to consult with an automotive electrician to check what they would use.

[got_bar_work]

Circuit breaker
That way it does both over current and instant trip with short circuit
They use bimetal strips for over current and a electo magnet for short circuit
A 350a cb with 2x rated current instant trip would be the go but i dont know if u can get them
That fuse looks like the car will burn to the ground before the fuse melts

[Reubs]

got_bar_work wrote:

Circuit breaker
That way it does both over current and instant trip with short circuit
They use bimetal strips for over current and a electo magnet for short circuit
A 350a cb with 2x rated current instant trip would be the go but i dont know if u can get them
That fuse looks like the car will burn to the ground before the fuse melts

I disagree. These aren't exact figures but this is the general idea put simply...

Consider your winch is using large cables (greater than maybe 70mm^2). The working temperature (continuous) for said cables would be at least 75 deg c but more likely 90 deg c. As long as your earth from body and chassis to the battery is also up-rated (to protect your oem loom) to around 70mm^2 with good solid clean connections and your positive feed is protected (as close to the battery as possible) with one of these ANL fuses then no short-circuit will see the car catching fire - the low resistance in the electrical return path from the point of fault back to the battery will see maybe 1000A. The fuse might blow in 1/5th of a second but the wire is very heavy and won't generate enough heat to catch fire or melt. In a case where the fault is smaller, the fuse might take longer to blow, but in this case the wiring will heat up more slowly (remember it is maybe good for 90 deg c) and the fuse will still blow in only a few seconds. If the fault is very small then the fuse won't blow but because you have very large cables they won't heat up and burn - instead you will likely flatten/damage your battery instead.

In industrial situations large conductors are similarly rated in this fashion - that is they have a 'fault rating' maybe several kA (thousands of amps) for a given time (usually 1 second). It is the job of the fuse or circuit breaker to act before the rating is exceeded, but the conductor WILL SAFELY see many times it's rated curent for a short amount of time until the protection operates.

Reubs

[got_bar_work]

Yeah thats all good in in the real electical world but dodgy auto electrical world we r trying to pull that 400a through 25-35mm2 cable
Also i dont care if the cable starts to melts its the flash at the point of of the short thays going to cause the fire probly in a car
I dont think some of the smaller car batteries could supply a big enough fault current to blow the fuse instanly
So its going to sit there arching away for a few seconds before it melts

[Mike57]

I was also going to suggest a circuit breaker but I have never seen one for an automotive application. The problem with the CB I think is that a winch start up current under load might spike to something quite high for a short time thus tripping the breaker unnecessarily.

[got_bar_work]

Ive only seen 100a cb used by a auto sparky
U probly could get bigger
The bigest problem with all this is the small fault current of the battery
At best its only going to be 3x rated current
Most cb need 7-12x rated current to trip instanly
We need to a fast blow 400a fuse
Something that will melt in under 5sec at 500a

[Reubs]

Mike57 wrote:

I was also going to suggest a circuit breaker but I have never seen one for an automotive application. The problem with the CB I think is that a winch start up current under load might spike to something quite high for a short time thus tripping the breaker unnecessarily.

Only reason you don't see rows of circuit breakers in cars instead of fuses is cost.

Thermal-magnetic circuit breakers generally have a similar current vs. time tripping curve to fuses. Most ac motors draw 6 times overcurrent on startup. I'm not sure of typical dc motor figures but miniature dc circuit breakers (Schneider Electric) still have a 7 to 14 times instantaneous trip - same as their ac counterparts, and most larger moulded case breakers are the same, thus motor startup current causing nuisance tripping is not an issue.

If you could get a magnetic only (no thermal protection - just an instant trip above rated value such as in a short circuit) circuit breaker with a trip setting around 400A then that would be the way to go. These exist in the industrial electrical industry but I've never seen one for an automotive application and an industrial 400A moulded case circuit breaker will cost more than most people's winches.

EDIT: Got_bar_work beat me to it LOL.

[coily96]

Up until now im isolating the power to my winch near the battery, now im seriously thinking of fusing it just to be safe.

The winch is new and only tested while running the wire onto the drum. Details on the winch, 9000lb tmax, 6.6hp motor, leads 25mm2

amp draw 90a @ 0, 190a @ 2000lb, 260a @ 4000lb, 335a @ 6000lb, 410a @ 8000lb, 425a @ 9000lb.

Battery used is a EA falcon battery 550CCA but a 660CCA is recommended.

What fuse does anyone recommend i use?

[Dr_Snapid]

Well honestly if your winch is isolated at the battery (at all times unless the winch is in use) you are probably safe without a fuse.

I've been giving this some thought and those who say a fuse could be troublesome for a winch could certainly be right. Those things draw like crazy, and some people say they have had the fuse blow.

Those who say it isnt safe to have massive live cables out the front are also right. In a prang might start a fire.

But if you isolate properly instead of fuse, you will be safe in an accident, plus you will at least be right there to hit the isolator if something goes wrong when you go to use the winch (it will likely happen right away) with no chance of blowing the fuse and being stranded.

As for a link between a dual battery system, you must fuse/breaker because you cant really isolate. But for a winch I reckon you already have the best setup, IMHO

[want33s]

Dr_Snapid wrote:

But if you isolate properly instead of fuse, you will be safe in an accident, plus you will at least be right there to hit the isolator if something goes wrong when you go to use the winch (it will likely happen right away) with no chance of blowing the fuse and being stranded.

The whole idea of the fuse, if it does go, is to let you know there is a problem for whatever reason and you can go to your onboard toolbox and retrieve a spare fuse.
Who is stranded anywhere?



I'm curious about this isolator idea....
How do you know if there is a short? Is it when the isolator switch block melts or when the cables catch fire?
Where can you buy 400A battery switches?