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Overland catches fire for no reason

ShadowsPapa

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Semantics, what part of that body/fender engine bay do you think is going to sustain 200amps without catching on fire?

The answer is none of it.

It's a complete waste of time, but if it makes you feel better by all means install one.

ETA: a disconnect relay and a fuse or breaker are obviously not the same thing. If you want to be certain, just unhook the positive cable.
Based on the vehicle catching fire without the winch being used, a disconnect would have possibly saved it because the power would have been disconnected next to the battery. There'd be no power going through cables to the winch.
The disconnect relay is the same as taking the winch cable off the battery - there's nothing there to worry about if the cable gets pinched or hit.
It's as good as pulling the positive cable at the battery, but you can do it with a switch. Turn it on to use the winch, turn it off and you have no power through those cables.
LOL - ya think I don't know the differences between fuses, relays and breakers?
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bgenlvtex

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Based on the vehicle catching fire without the winch being used, a disconnect would have possibly saved it because the power would have been disconnected next to the battery. There'd be no power going through cables to the winch.
The disconnect relay is the same as taking the winch cable off the battery - there's nothing there to worry about if the cable gets pinched or hit.
It's as good as pulling the positive cable at the battery, but you can do it with a switch. Turn it on to use the winch, turn it off and you have no power through those cables.
LOL - ya think I don't know the differences between fuses, relays and breakers?
Well your first post goes on about fuses and circuit breakers then evolved to a master disconnect, so maybe you can see where I would think that.

Properly installed and shielded cabling does not require a master disconnect. It of course is a secondary safety that adds security both electro-mechanically as well as psychologically.

My point has never been that there is no virtue in a disconnect (although I don't personally use them) simply that a fuse or breaker is a waste of time and effort.
 

ShadowsPapa

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Well your first post goes on about fuses and circuit breakers then evolved to a master disconnect, so maybe you can see where I would think that.

Properly installed and shielded cabling does not require a master disconnect. It of course is a secondary safety that adds security both electro-mechanically as well as psychologically.

My point has never been that there is no virtue in a disconnect (although I don't personally use them) simply that a fuse or breaker is a waste
of time and effort.
As often happens, I doubt we are that far apart.........
I had originally forgotten about the disconnect switches, at this point it would be my preference if I were to do something along the line of "safety" aside from isolating the cables and routing them safely. That's a biggy there. Large enough cables, routed safely, where they can't be easily pinched or wear or scraped.
Many many classic car collectors use battery disconnects - totally disconnect the battery when the car isn't in use.
In fact, at many high-end shows, you MUST disconnect the battery in some way.
 

bgenlvtex

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As often happens, I doubt we are that far apart.........
I had originally forgotten about the disconnect switches, at this point it would be my preference if I were to do something along the line of "safety" aside from isolating the cables and routing them safely. That's a biggy there. Large enough cables, routed safely, where they can't be easily pinched or wear or scraped.
Many many classic car collectors use battery disconnects - totally disconnect the battery when the car isn't in use.
In fact, at many high-end shows, you MUST disconnect the battery in some way.
At this point we are saying the same thing, yes.

If what I think happened in the OP pics is what actually happened then :
(A) properly installed and shielded cabling would have kept if from happening
(B) A master disconnect in the off position would have kept it from happening
(C) any combination of A and B would have kept it from happening
 

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Early Land Rovers (Series) had a negative battery disconnect under the dash. Not a bad plan as isolating the negative entirely shuts everything down. Of course that is a little more difficult to accomplish in a vehicle with two batteries. In this case, a battery disconnect on the battery would have been worthless. Holy hell opened up around that battery and only a fool would have attempted to stick their paw in there and throw the switch. This is a great example of where the postmortem analysis shows that the only real fix was prevention as correction is not possible.
 

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TLife

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a fuse or breaker is a waste of time and effort.
This is completely incorrect.

I don't know the details of this fire, but a properly sized breaker will greatly reduce if not totally eliminate the risk of a fire downstream of it. To correctly size the breaker you need to have know motor use periods and have time current curves for the breaker you're looking to use. Here's an article that explains it decently:

http://comeupusa.com/2016/01/how-to-choose-the-right-circuit-breaker-for-your-winch/

Let's say that a bolted fault (direct positive to negative fault) results in a 1200A current (hypothetically, because I'm not going to look up this specific battery). Looking at the example TCC from the article the breaker will trip in approximately 0.3 seconds. While this will not be without some damage, certainly it won't be causing any fires in 0.3 seconds.

Please don't tell other people that a breaker is a waste of time and effort if you're not properly informed on the subject, it's genuinely a safety issue.
 

bgenlvtex

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This is completely incorrect.

I don't know the details of this fire, but a properly sized breaker will greatly reduce if not totally eliminate the risk of a fire downstream of it. To correctly size the breaker you need to have know motor use periods and have time current curves for the breaker you're looking to use. Here's an article that explains it decently:

http://comeupusa.com/2016/01/how-to-choose-the-right-circuit-breaker-for-your-winch/

Let's say that a bolted fault (direct positive to negative fault) results in a 1200A current (hypothetically, because I'm not going to look up this specific battery). Looking at the example TCC from the article the breaker will trip in approximately 0.3 seconds. While this will not be without some damage, certainly it won't be causing any fires in 0.3 seconds.

Please don't tell other people that a breaker is a waste of time and effort if you're not properly informed on the subject, it's genuinely a safety issue.
Either you didn't read, or didn't understand what you linked.

A circuit breaker will have to function under full load for some prescribed period of time before it trips.

In their example a 380a current draw on a 190a breaker trips at 30 seconds.

Meaning the welding machine is running under the hood for 30 seconds before the breaker interrupts the circuit.

By that time it is on fire, metal is on fire, composites are on fire and you aren't going to put it out with a 2lb extinguisher.

ETA : specifically they are talking about protecting the winch motor in that link.
 

Factoid

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I didn't think that was his point. in a catastrophic short, think full battery amperage that would be shut down almost immediately.
 

ShadowsPapa

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I didn't think that was his point. in a catastrophic short, think full battery amperage that would be shut down almost immediately.
EXACTLY. If a wire rubs for some reason and you get a full positive voltage to the negative, it would trip.
My fear is that you are driving along and minding your own business and some idiot pulls out and you get a front end or front corner smack and the cable running to your winch is pinched - everything that battery can send down that cable and that the cable can handle suddenly hits ground - melted wires, fire.
That's my thing - not that the draw of a normal winch will melt wires - if you have done your work your wires are likely too large anyway.
My fear is the unknowns.
So I would opt for a full electric disconnect via a switch like sold for that exact purpose, or some other protection that would cut or break the circuit in case of a full GROUND situation. Front end hit, truck trauma that can otherwise be fixed becomes impossible after a fire hits that aluminum (and plastic and vinyl)

The point isn't normal winch draw, it's the full power of the battery under an abnormal situation.
If I'm using the winch, I have CONTROL over it, the draw it has, and more - I'm right there watching over things.
It's when I am NOT using it I am wanting to cover.
 

TLife

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Either you didn't read, or didn't understand what you linked.

A circuit breaker will have to function under full load for some prescribed period of time before it trips.

In their example a 380a current draw on a 190a breaker trips at 30 seconds.

Meaning the welding machine is running under the hood for 30 seconds before the breaker interrupts the circuit.

By that time it is on fire, metal is on fire, composites are on fire and you aren't going to put it out with a 2lb extinguisher.

ETA : specifically they are talking about protecting the winch motor in that link.
You're failing to realize the difference between motor full load current, which occurs when the motor is being used as designed, and a bolted fault, which occurs when there is a very low resistance connection between the positive and negative terminals of the battery. In a fault situation, which is what likely happened here, the motor full load current is totally irrelevant. In that situation as much current as the battery can provide will be pumped out until the circuit is broken, either by totally melting whatever was causing the fault or an interrupting device opening the circuit.

Trust me when I tell you that I read and understood the link.
 

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bgenlvtex

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I didn't think that was his point. in a catastrophic short, think full battery amperage that would be shut down almost immediately.
Sheet metal won't carry 190a without catching fire.

You would have to have direct ground to a contactor capable of supporting the load and not catching on fire before the breaker tripped.

Sheet/gauge metal isn't that conductor.

That link is discussing a protection circuit for the winch.
 

bgenlvtex

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You're failing to realize the difference between motor full load current, which occurs when the motor is being used as designed, and a bolted fault, which occurs when there is a very low resistance connection between the positive and negative terminals of the battery. In a fault situation, which is what likely happened here, the motor full load current is totally irrelevant. In that situation as much current as the battery can provide will be pumped out until the circuit is broken, either by totally melting whatever was causing the fault or an interrupting device opening the circuit.

Trust me when I tell you that I read and understood the link.
It won't be "pumped out" into a material that won't accept it.

If you bridge the positive and negative cables with a piece of coat hanger on a 199a breaker, which do you think will happen:
The breaker will trip immediately.
The coat hanger will turn cherry red and light shit on fire.

Pick one
 

TLife

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It won't be "pumped out" into a material that won't accept it.

If you bridge the positive and negative cables with a piece of coat hanger on a 199a breaker, which do you think will happen:
The breaker will trip immediately.
The coat hanger will turn cherry red and light shit on fire.

Pick one
It depends on how the breaker is sized, what the maximum output of the battery is and the physical properties of the coat hanger. Assuming it was correctly hooked up somehow (battery positive > coat hanger > breaker input > breaker output > coat hanger > battery negative) and the breaker is correctly sized for whatever application you're imagining, the breaker will trip. That's literally its entire job.

Don't do this, but if you stick something metal into both prongs of an outlet and touch them together you will get a relatively small spark and immediately trip the breaker. The breaker will trip well before you could ever dream of lighting anything on fire. That's its job.
 

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Badlands 12000 winch at full load draws 300 amps. (Look in the owner manual)
Warn 12000 pound winch pulls something like 470 amps.

According to Warn specs, they pull a whole lot more than most of their competition as far as amperage.

There are disconnect switches which I believe are 350 amp switches (allow you to turn the power to your winch on or off from the dash - it's basically similar to a Ford style starter relay but for more constant duty)

I think Warn might call it a "power interrupt switch". Basically, no power to the winch unless you turn the relay on. That would seem the ultimate safety. Not sure what Warn's version is rated at.
Sorry for necromancing an old thread … but I wired my Badlands 12000 winch with the Warn Power Interrupt kit inline with the relay part connected to my AUX4, and on the battery side is a 500A fuse. Blew that fuse Saturday trying to winch my JTR out of the mud. Suction was insane and my line was bunged which didn’t help. But I could have been pulling more than 500A right?
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