Fusing a winch
- Thread starter brushogger
- Start date
slomatt
Adventurer
Del City is a good company. I've ordered from them several times and have never had a problem.
- Matt
The biggest circuit breaker that is available for DC applications like this is about 200 amps. Even at a 25% pull on the winch, you're drawing that much. At full pull you're drawing 400+ amps. There simply isn't a circuit breaker available that can deal with that much. A 450 amp fuse is like $7-8. Even the 200 Amp reset-able circuit breaker is ~$50. So you could blow a fuse 7 or 8 times before it would pay off to get a circuit breaker (even if one were available). Also, the only reason you would blow one is because you got a short in the circuit, which is going to be very seldom and hopefully you've dealt with the issue causing the short before you blow 8 fuses.
Thanks Matt, I've hopefully found a place in town that has them. But otherwise, I'll look at getting them from Del.
toyotech
Expedition Leader
450 amp fuses are 7-8$. The Toyota 100amp alternator fuses are $50-100 each.
450amp fuses isn't gonna protect anything will it? Whole point of a fuse is to protect the wires from melting. The wire would catch fire and melt before a 450 amp fuses goes??
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450amp fuses isn't gonna protect anything will it? Whole point of a fuse is to protect the wires from melting. The wire would catch fire and melt before a 450 amp fuses goes??
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No, 450 amps will not necessarily melt the wire. In my particular case, I've got 12' of 000 cable. At 450 amps, the 000 wire will be putting out about 150 watts of heat which is about enough to raise the temperature in the cable by 1 degree Celsius every 8 seconds. So if you ran the winch at a full 8000 lb pull for two minutes straight, you'd raise the temperature of the cable by all of 15 degrees C. At that point your winch would probably melt.
The purpose of the fuse is to protect the batteries and wires in the event of a direct short. If you have a direct short with no fuse, you have only as much resistance in the circuit as is provided by the cable, connections, and the internal resistance of the battery. If we assume that the resistance of the battery dominates the other two, you could have a potential current of 4300 amps, which will blow up the battery and/or melt things especially if you have a dual battery set up with high amperage capacity.
onetraveller
Adventurer
It's an interesting discussion, but I am a bit surprised. I've installed two different Superwinch Tiger Shark 9500s in the past 3 years and they both came with inline circuit breakers that mount at the battery. It's interesting that the Talon does not.
This is the type of circuit breakers that came with both of my winches.
https://cdn.shptrn.com/media/mfg/4377/media_document/4398/InstallationGuideofSuperwinchTigerShark950011500CircuitBreaker.pdf?1363972868
Mike
This is the type of circuit breakers that came with both of my winches.
https://cdn.shptrn.com/media/mfg/4377/media_document/4398/InstallationGuideofSuperwinchTigerShark950011500CircuitBreaker.pdf?1363972868
Mike
Attachments
That's interesting. That is actually 4 individual circuit breakers in parallel with buss bars. I'm a structural engineer, not an electrician, but my father is. When I suggested circuit breakers in parallel, he said that while that works in an ideal world where all of the breakers trip at once, really, they all have minutely different trip currents as well as different resistances. One will trip before the others, the current will spike in the others until the next one trips, etc. etc. etc. So I said, OK so what. Well, each circuit breaker has a certain resistance to it, as you dump all of the current back through the remaining circuit breakers, the voltage drop across them increases. Eventually, if your fault is large enough and the circuit breaker is small enough, you can arc through the breaker and cause a fire/explosion depending on the breaker. Albeit that most likely is only really a danger on the big high voltage breakers that they have on transmission lines. I still think it would be very difficult to get a parallel circuit breaker system together that would behave in a predictable manner without explicitly testing the setup. Which seems like a lot of faff to go through.
It's also interesting that the setup you have a picture of has two 30amp breakers and two 50amp breakers. Unless the 30 amp breakers have lower resistance than the 50 amp breakers, the 50 amp breakers are effectively useless as the circuit would only (ideally) carry 4x30 amps before starting to trip not 2x30+2x50. Unless of course those are there because they are accounting for the effect mentioned above. IDK. Something else to consider i guess. I ended up just running mine commando for our trip on the OBCDR this last weekend, no fires yet, but I will be getting one before our next trip on the TAT.
Exactly. If I had a couple of feet worth of cable going from the battery down to a permanently mounted front winch, I wouldn't worry about it. As you said, typically people don't fuse big winches. But having 12' of 000 cable wrapped through my frame and back up to plugs in the bed, there's all sorts of opportunity for the cable to get pinched between the frame and the body or for the insulation to get worn through from vibrations or for a big rock to crush it against the frame. I've routed the cable to minimize those locations and protected it where I can, but you can't prevent everything.
brianjwilson
Some sort of lost...
Maybe it's just me, but if you're worried about tampering, I would just install a blue sea or similar battery switch near the battery and leave it off until I need to use the winch. Yes it is more expensive, but I'm not sure a 500 amp fuse is going to really protect anything.
https://www.bluesea.com/products/9003e/e-Series_On_Off_Battery_Switch
https://www.bluesea.com/products/9003e/e-Series_On_Off_Battery_Switch