NorthWest Kayak Anglers
Kayak Fishing => For Safety's Sake => Topic started by: Martial Mathers on September 08, 2014, 10:43:25 PM
-
I was getting ready to launch off the beach on Sauvie's early Sunday morning to anchor up in 50' and try for a King. Fortunately I left my hatch open after plugging the ff into a fully charged, 12VDC, 7ah battery. I was tying up my rig and saw smoke coming from the hatch. I first thought it was was steam from warm air in the hatch meeting the cool morning air. I waved my hand over the hatch and it was like an oven. I reached in and burnt my hand. Luckily, my wits stayed with me. I immediately grabbed the battery by its base, brought it on deck, and disconnected the ff from the terminals with a Leatherman. My kayak is alright, but the casing on the power cable melted from the battery almost all the way to the head unit. This is troubling because, if I had closed the hatch; it's very likely that it would have quietly burned a hole through my hull and sunk me in 50'. I would have needed a powerboat rescue, and become a running joke on ifish. What happened is a total mystery to me. I'm fairly experienced with low voltage wiring and devices. No, the leads weren't crossed, and that wouldn't have done this anyway, there's a diode in the ff. Anyway, fuse your fishfinders for safety. That's what I'm going to do (if it still works). Humminbird is sending me a new power cable, so we'll see if I get a display again.
-
Sorry to hear about your meltdown. I'm sure you weren't entirely literal on your rescue comment. But in case you were, let's agree that most of us are fully capable of swimming to shore in that part of the river. I think it's important that we as kayak fishermen assume we'll perform self rescue in most situations. We should always promote that we are an asset on the water, rather than a liability. Sorry, I don't mean to hijack your thread. Now back to that battery.... I wonder why it didn't just fry your ff? Must have been a short somewhere.
-
Can a mod sticky this and/or the other one? Seems to be a continuing issue, and also one that many people think can't happen.
-
Sorry to hear about your meltdown. I'm sure you weren't entirely literal on your rescue comment. But in case you were, let's agree that most of us are fully capable of swimming to shore in that part of the river. I think it's important that we as kayak fishermen assume we'll perform self rescue in most situations. We should always promote that we are an asset on the water, rather than a liability. Sorry, I don't mean to hijack your thread. Now back to that battery.... I wonder why it didn't just fry your ff? Must have been a short somewhere.
I wouldn't have been in danger. I'd have a pfd on, and am quite capable of swimming to shore, especially in 70degree water. I just meant with all the boats around, someone would have scooped me up and had a good laugh about it. I don't know what part of electrical theory explains what happened, but it think it was caused by condensation in the plug part of the power cable (that plugs into the fishfinder). I'm going to reread the other post about a fishfinder fire. I wonder if that was also a hummingbird.
-
Never done marine electronics but fuse everything added on a car. Lawrence Mark 4 dsi 12v 7a batterie , what size inline fuse ? I was thinking 10 amp. All input appreciated.
-
Never done marine electronics but fuse everything added on a car. Lawrence Mark 4 dsi 12v 7a batterie , what size inline fuse ? I was thinking 10 amp. All input appreciated.
I use 5. You need to think about what the safe rating of your wires is. The recommended "Maximum amps for power transmission' for 14 gauge wire is like 5.9A.
-Allen
-
Humminbird lists a 1 amp fuse for my fishfinder. That's probably sufficient for most other FF models. The power cable it came with looked like 22AWG which is only rated for maximum 3.7 amps. I'm still plexed by what happened. In theory a device should never draw more current than it needs. A device that requires less than 1 amp, shouldn't pull enough current to turn red hot, and melt the PVC casing off its wires (even if the connectors get damp). This is a factory plug that runs from the head unit straight to the battery. There is no way to mess it up. Reverse polarity is the only possible error, and there's a diode to counter that. I've already PM'd Smokeyangler; I'm very curious if his unit that burned up is also a Humminbird.
-
I have some 2.5 amp I will start with if it blows I will put in a 5 amp and always carry spares. Thanks for the info.
-
Never done marine electronics but fuse everything added on a car. Lawrence Mark 4 dsi 12v 7a batterie , what size inline fuse ? I was thinking 10 amp. All input appreciated.
I use 5. You need to think about what the safe rating of your wires is. The recommended "Maximum amps for power transmission' for 14 gauge wire is like 5.9A.
-Allen
How do you keep your fuse from oxidizing going out in the salt and all. Everytime I put one in it lasts one or two days of fishing on the salt. Then in frustration I take it out.
-
Dirk1730.....This style fuse holder will prevent oxidation http://www.wiringproducts.com/atm-mini-waterproof-fuse-holder-16-ga-wire.html
You can find these at most auto parts stores too.
-
In theory a device should never draw more current than it needs. A device that requires less than 1 amp, shouldn't pull enough current to turn red hot, and melt the PVC casing off its wires (even if the connectors get damp).
It's not theory - it is a fact that the current draw is inversely proportional to the resistance of the load. What happened is that the resistance became greatly reduced, commonly called a short circuit. Check all the connectors. Sometimes a crack develops between poles and gets water or some other conductive crap in the crack. I used to work in a welding shop and the plugs there would get metal dust in the cracks and cause some poor welder to poop his pants when the plug blew up.
I use 5. You need to think about what the safe rating of your wires is. The recommended "Maximum amps for power transmission' for 14 gauge wire is like 5.9A.
-Allen
That current rating is ultra conservative, although I did see it listed in one table. A 14 gauge wire will safely conduct at least twice that, although that is not the point. The point is that you fuse for the load - two to three times the max current is good. I fuse my FF at 2A.
-
Most fuses are designed to open and clear the current through a system when that current of the system exceeds roughly 1.4 to 1.5 times the rated current value of that fuse. With a circuit such as a depth finder, you do not want the current to go too much more than the rated current for the depth finder, which is listed in the manual. Any current value that will cause an appropriately matched fuse to open in your electrical system indicates that there is a problem with your system and you don't want that system to operate anyway until the problem is identified.
My depth finder operates at about 650 mA. I have used a 500 mA fuse with it and it works just fine. I have also used a 1 A fuse and that works too, but the idea of more than an amp running through my system is enough to make me nervous. 500 mA fuses are kind of tough to find in stores. I have found them more often in the tubular form of fuses, so that is the type of fuse holder I use. I use the ones that say they are rated for marine use. They have a rubber casing. To keep them from corroding I squirt dielectric grease into the fuse holder before I put the fuse in, then wrap it in a few wraps of electrical tape after closing it up. That works really well.
-
I have also used a 1 A fuse and that works too, but the idea of more than an amp running through my system is enough to make me nervous.
Why does it make you nervous? Plenty of FF's draw 1A or more through the same power cables and generate negligible heat.
-Allen
-
500 mA fuses are kind of tough to find in stores.
Have you checked out any online sources? I know McMaster has <1A fuse and I just quickly saw a couple options in the 630 - 800 mA range on Radio Shack's site (probably won't find it in their stores). I bet Graybar, Platt or even Fry's would have them locally though. I agree with you and might also downgrade if I had a high-end unit. I currently run a 1A and feel fine with it for my cheap unit.
Martial - I would look on the cables and find where the burn ends. Since you stated that it didn't make it all the way to the unit, I'm guessing that there was some kind of internal short. That short is probably near where the burn ends. Is that part of the cable near anything that could have pinched it? Say like a hatch or a through hull fitting, zip tie, etc...?
-
I have also used a 1 A fuse and that works too, but the idea of more than an amp running through my system is enough to make me nervous.
Why does it make you nervous? Plenty of FF's draw 1A or more through the same power cables and generate negligible heat.
-Allen
I say that given what my ff normally draws. If it was rated at an amp or so, that much current wouldn't bother me but two amps would.
-
How do you keep your fuse from oxidizing going out in the salt and all. Everytime I put one in it lasts one or two days of fishing on the salt. Then in frustration I take it out.
If you put the fuse and its holder inside a waterproof battery box, you won't have any problems with the fuse oxidizing. Shown below is a battery box I made from an inexpensive Walmart waterproof box. You can find descriptions of a huge number of ways to make a battery box at http://www.northwestkayakanglers.com/index.php?topic=7606.0 .
-
500 mA fuses are kind of tough to find in stores.
Have you checked out any online sources? I know McMaster has <1A fuse and I just quickly saw a couple options in the 630 - 800 mA range on Radio Shack's site (probably won't find it in their stores). I bet Graybar, Platt or even Fry's would have them locally though. I agree with you and might also downgrade if I had a high-end unit. I currently run a 1A and feel fine with it for my cheap unit.
Martial - I would look on the cables and find where the burn ends. Since you stated that it didn't make it all the way to the unit, I'm guessing that there was some kind of internal short. That short is probably near where the burn ends. Is that part of the cable near anything that could have pinched it? Say like a hatch or a through hull fitting, zip tie, etc...?
Yeah, I guess I'm spending too much time in hardware stores. I imagine a place like radio shack or Fry's would have better options. Fry's has really gone down hill. It makes me sad that it's becoming another Best Buy or Circuit City.
-
I guess I'm spending too much time in hardware stores.
Blasphemy! LOL
Fry's has really gone down hill. It makes me sad that it's becoming another Best Buy or Circuit City.
Agreed, very sad to see. RadioShack has really gone downhill as well; and I didn't think that was possible!
-
I guess I'm spending too much time in hardware stores.
Blasphemy! LOL
Fry's has really gone down hill. It makes me sad that it's becoming another Best Buy or Circuit City.
Agreed, very sad to see. RadioShack has really gone downhill as well; and I didn't think that was possible!
I can't think of the last time I went to RadioShack and found what I was looking for.
-
I have also used a 1 A fuse and that works too, but the idea of more than an amp running through my system is enough to make me nervous.
Why does it make you nervous? Plenty of FF's draw 1A or more through the same power cables and generate negligible heat.
-Allen
I say that given what my ff normally draws. If it was rated at an amp or so, that much current wouldn't bother me but two amps would.
If you are spiking enough to trip a 1A with your unit, I don't think the difference between 500 mA and 1A is going to cause significant more damage. The damage was already done at that point.
-Allen
-
When I had my fire I didn't have my fish finder plugged in. It was a Lowrance Elite 4 DSI fish finder. I did have my battery connected to the fish finder cord though.. My fire was due to a cigarette lighter extension receptacle that I had added to the wiring. It had gotten wet at ORC, dried and the corrosion from the salt water created a path for the electricity to flow. It created enough heat to start the wiring and socket to catch on fire. I will never go without a fuse again. I learned a valuable lesson.
-
I know this is an old thread but since it is stickied I figured it would be worth updating.
I have a background in electronics and I have been doing marine wiring on and off for a lot of years. I see some controversy in this thread regarding fusing. The fuse is intended to protect your wiring, it is NOT intended to protect the load. The load (like a FF) will/should have its own fuse.
According to ABYC E-9.11.b "The rating of overcurrent protection devices used to protect a load other than a DC motor shall not exceed 150% of the current carrying capacity of it's supply conductor"
As I understand it, the 150% figure is to allow for short term current spikes (like from inrush current when you turn on a device) for a fully loaded wire circuit. Extended overcurrent situations will still blow the overcurrent device before the wiring is compromised. Best practice in normal situations where the circuit is not fully loaded is to rate the overcurrent device for the maximum of the wire or a bit below. According to the same ABYC spec, the maximum allowable current (under 50V) for common wires size is below. The two values are "outside engine spaces"/"inside engine spaces". I prefer to err on the side of caution and go for the lower value.
18: 10A/5.8A
16: 15A/8.7A
14: 20A/11.6A
12: 25A/14.5A
ABYC E-9.10 says Overcurrent Protection Device Location - Ungrounded conductors other than cranking motor
conductors shall be provided with overcurrent protection within a distance of 7" of the point at
which the conductor is connected to the source of power measured along the conductor. This means you need to place your fuse right at the battery rather than at the device.
You can certainly use a lower value fuse if you like, however as you go to lower values corrosion and mechanical stress will have a larger chance of damaging the fuse so it seems better to me to go for the largest hunk of metal fuse that is reasonable and still protect the boat.
Hope this helps folks in the future.
The spec is available here: https://law.resource.org/pub/us/cfr/ibr/001/abyc.E-09.1990.pdf (https://law.resource.org/pub/us/cfr/ibr/001/abyc.E-09.1990.pdf)
-
Thanks for the reference. Brings back my old boat building days. It's worth the effort to research the correct way to wire/fuse something. It's so much easier to troubleshoot when something is wired properly.... and it won't catch on fire.