Check Your Electric Cable Zip Ties!

[svHyLyte]

A close friend of ours suffered a mishap that nearly cost him his boat this past week. He had done a major refit in anticipation of the Regatta del Sol al Sol and decided to take the yacht out for sea trials with a friend. Evidently, they ran off-shore about 20 miles or so and then finally headed back. On the return they lost the wind and so began motor sailing. As he related, at some point one or more of the "old plastic zip ties" securing the positive cable from his battery bank to the main battery switch broke and which allowed the cable to drape down and come in contact with the exhaust manifold on his engine. Of course, the insulation shortly melted and as soon as the copper core came in contact with the manifold it shorted out and arced, setting the engine bay on fire. He couldn't cut the power as it was the cable between the batteries and the switch and unfused. He indicated that the automatic Halon system discharged but did nothing as he had no way to shut down the engine which, evidently, kept running and discharged the gas through the exhaust, and the arc continued the fire until the battery cable itself finally melted through. Somehow they did get the fire out but lost the engine and so drifted until they finally got enough wind to make it back to Tampa Bay. There they rode the flood to our River and were finally able to make it back to our Club under sail alone. Of course, they had lost all their electronics and the VHF with the fire and evidently didn't have a hand-held to call for aid once they were within range. He was very tired and very dejected looking but declared he was going to rebuild in time for the race if at all possible!

With this, I am going to recheck all of the zip-ties on our power cables to ensure they're good (and where possible replace any supports with insulated stainless loom clamps) and make sure that nothing can come in contact with the engine should anything come loose! I am also going to fuse the positive battery cables within 6" of the lugs to ensure that should something get sideways despite the foregoing precautions, the power would be cut quickly at relatively low amperage. Others might care to consider doing the same.

FWIW...

[denverd0n]

Originally Posted by svHyLyte

I am also going to fuse the positive battery cables within 6" of the lugs...

This is why the ABYC standards do not allow what your friend had, a long run from the battery to a switch without any fusing. The standards say fuse within 7" of the power source, but 6" is 14% better!

[fallingeggs]

Originally Posted by denverd0n

This is why the ABYC standards do not allow what your friend had, a long run from the battery to a switch without any fusing. The standards say fuse within 7" of the power source, but 6" is 14% better!

It is interesting that this guy's power cable to the switch wasn't fused at all. One question on this forum would have cleared it right up!

I am in the process of re-doing all my power cables, and actually to the point where I'm securing them against movement and chafe, so this post has good timing. I moved my selector switch out of the engine compartment, but I still have the cables to the starter and from the alt to consider.

Cheers.

[Cheechako]

I have seen very few boats that have a battery bank fuse actually. Maybe because I see mostly old boats. Upgraded or modern boats have it.
The other thing is zip ties... there are a lot of cheap ones out there that break, or simply don't hold properly. Many are not UV protected either. They are handy but in many ways I don't like them much.

[a64pilot]

Anything even remotely critical, I like to use these, airplane mechanics call them DG clamps
MS21919 DG / WDG CLAMPS from Aircraft Spruce

I dislike zip ties, they were years ago not allowed for military aircraft wiring, they break wires and age and fail, we tied wires instead, called it "lacing" I would have thought sailors being such knot fanatics would lace wires as a matter of course, it's much stronger, neater and even cheaper

http://makezine.com/2009/07/28/lost-...-cable-lacing/

[btrayfors]

ABYC does not permit the use of plastic wire ties in engine spaces. You must use metal retainers, usually those with black insulated beds.

That was his first problem.

Next, could he not reach the battery bank to disconnect the positive cable?

Did he not have handy a pair of cable cutters to snip the cable?

The Sears Craftsman "HandiCut" tool would have done nicely to snip the positive wire. I can't live without these....have 3 of them!
Craftsman Handi-Cut Utility Cutter, 3 7/8-in | Part Number 37301 | Sears PartsDirect

Bill

[Cheechako]

Originally Posted by a64pilot

Anything even remotely critical, I like to use these, airplane mechanics call them DG clamps
MS21919 DG / WDG CLAMPS from Aircraft Spruce

I dislike zip ties, they were years ago not allowed for military aircraft wiring, they break wires and age and fail, we tied wires instead, called it "lacing" I would have thought sailors being such knot fanatics would lace wires as a matter of course, it's much stronger, neater and even cheaper

Lost Knowledge: Cable Lacing | Make:

Yep, those D clamps are great especially for battery cable size stuff. Or big bundles.

[StuM]

Originally Posted by a64pilot

I dislike zip ties, they were years ago not allowed for military aircraft wiring, they break wires and age and fail, we tied wires instead, called it "lacing" I would have thought sailors being such knot fanatics would lace wires as a matter of course, it's much stronger, neater and even cheaper

Lost Knowledge: Cable Lacing | Make:

That's an interesting site.

Note that in the illustration following "Here’s an illustration from an old ARRL Amateur Radio Handbook, showing the marline hitch:", only (B) shows the marline hitch.

[fritzdfk]

Actually ABYC standards make an exception for battery to starter cables, they are not required to have a fuse. It is a good idea though.

[wsmurdoch]

Originally Posted by fritzdfk

Actually ABYC standards make an exception for battery to starter cables, they are not required to have a fuse. It is a good idea though.

My engine manual says my starter motor draws 300A. My fuse at the starter battery is 250A. (The starter motor does not run long enough for the fuse to blow.) 250+A x 12V = 3000+W. That is a lot of heat in a small amount of time. I'd think a switch would be better than (or a great addition to) a fuse in the case of a arcing short and fire. Of coure, my car (and millions of others) has neither a fuse nor a switch.

There are a lot of questions here. I know I don't have the answers.

[dfelsent]

I remember clearly the rant of a co-worker in the early eighties.
25 cents for a cable tie! No way. I'm faster and cheaper and more durable with lacing. He was. I did not have the speed he did.
He used the 'NASA tie' . I have used that with whipping twine when I haven't has zip ties.

[Diesel Bill]

I guess it's back down into the hole for me. Thanks for posting as I need to clean up the heavy battery cable runs down in the engine compartment. They are fused but lying loose and look very untidy and non shipshape. How embarrassing. I was having so much fun varnishing the salon sole, I just got burned out working in the hole and blew it off.
I feel better after confessing, so I promise I'll take care of it .

[oleman]

No rigid plastic material I have yet to use (I have been at this trade for 60 years) is viable in sunlight! Some is known as UV tolerant but every one I have ever used on farm equipment breaks in less than a year if left in mother nature. They also do not work well in the engine compartment of anything gas or diesel. The slit flexible tubes are little better, used by most vehicle makers. All are temporary wiring solutions.
SS synthetic rubber lined cable clamps (aircraft cable clamps) are much better.
Lead acid outgassing will destroy neoprene rubber if near the battery.

[masonc]

HellermannTyton makes these for solar industry, this is what we use on rooftop installations.
https://www.hellermanntyton.com/prod...l250/111-01265

[Tessellate]

Good reminder. I have my starter battery fused with Blue Sea terminal fuses, per Maine Sail's recommendations: Battery Bank Fusing Photo Gallery by Compass Marine How To at pbase.com

I would think multiple zip ties would have to break before a starter cable could get loose. Interesting that ABYC doesn't allow zip ties in the engine space. Mine has many zip ties, and that was never remarked on by the surveyor or engine mechanics. Do you have a link to that? I couldn't find any reference citing it - https://www.google.com/search?q=abyc...space+zip+ties

I've never had a zip tie break, in any location. Bigger cables are cable-clamp secured though. Doesn't mean it can't happen, but it's probably pretty rare. Engine spaces don't have UV exposure. I would think it's more likely for the screw holding a cable clamp or zip tie to pull out than for a zip tie to break. The screws get vibrated/pulled, and sometimes the wood they're in gets degraded, so it's a good idea to monitor that.