Okay to Repurpose Radar Cable?

[Canibul]

Lightning fried our radar, and I don't plan to replace it. Thinking about salvaging the antenna mount up above the mast spreader with mods to hold a couple of 51 watt LED offroad lights and a loud hailer speaker. The Furuno radar cable has 13 conductors and a coax inside another shield and already runs from the helm to the mast mount. Is there any reason I shouldn't triple up six of those into two pair for the light, and use a couple of the others for the speaker? Would sure be easier than removing it and running two new pair. It also nicely stops up all the holes made for it.

Any thoughts?

[Jim Cate]

Sure, why not? If the combined cross sectional area of the wire is adequate for the current, I don't see any problem. I would do the same thing!

Jim

[rwidman]

Not so fast. Determine the size of the conductors, then determine the maximum current capability for that size conductor and multiply that by the number of conductors to be paralleled. Then install circuit protection for that value and hope that none of the conductors ever fail and overload the remaining conductors.

It's a pretty crappy way to wire something and not good electrical practice because of what I posted in the previous sentence. Running new, properly sized and protected (electrically) wires is the correct way to do this and will give you the satisfaction of knowing you have done something right, not half assed.

[ryon]

If it withstood a lightning bolt, It should be able to handle a couple of 50 watt lights.

[Jubilee39]

Originally Posted by rwidman

It's a pretty crappy way to wire something and not good electrical practice because of what I posted in the previous sentence. Running new, properly sized and protected (electrically) wires is the correct way to do this and will give you the satisfaction of knowing you have done something right, not half assed.

While not in "accepted" practices wire is wire. Properly sized and insulated wire will work to do the job. The problem may come in resale though. If you took shortcuts here, where else did you.?

[rwidman]

Originally Posted by ryon

If it withstood a lightning bolt, It should be able to handle a couple of 50 watt lights.

That's not the way we determine the safe ampacity of conductors. It's the size of the conductors that counts.

[transmitterdan]

At least 2 of the cables in the multiconductor cable should be larger cables that powered the magnetron. The rest will be pretty small wire. The coax (was for video) is not good for much as it is usually very small and not easy to terminate.

You may want to consider LED lights as a way to limit the current draw. The loud hailer could use a few of the smaller wires paralleled. The hailer is about 1 ampere when being used but usually not for long. The main concern is high resistance of the long wire reducing the loudness too much. If the hailer is loud enough when you are done you should be ok. Be sure to weather seal the terminations to help delay corrosion.

[hellosailor]

Sometimes you can get away with it. Sometimes, insulation has melted on some of the conductors, or one of them is blown, you won't know for sure even if you meter it out because it could just be half-failed right now.


If it meters out, if it works, if one of the conductors doesn't overheat from getting just a little more current and then going into thermal runaway...


Personally I don't think I'd trust anything that might have been lightning-struck. But if the load for the LEDs is small compared to the capacity of those wires, i.e. HALF of what the three pair can carry, and you've got a good extinguisher on board, by all means try it. I just wouldn't leave them on while I was sleeping, until they'd proven themselves to be well-behaved for a while.

[Canibul]

Originally Posted by Jubilee39

While not in "accepted" practices wire is wire. Properly sized and insulated wire will work to do the job. The problem may come in resale though. If you took shortcuts here, where else did you.?

Yeah, that's pretty much my thinking on it, copper is copper. Electrons don't stop to examine receipts to make sure where it was purchased or when. Doesn't matter if it's old copper or new copper, long as it's still copper.

Re the resale, the truth is that if I duct taped lamp cord to the mast it would be an improvement over some of the wiring the three previous owners made. I am finding stuff that astounds me. Yesterday I discovered that I have an ac outlet under my inside helm station in which the wires ( orange extension cord) are twisted together and insulated with paper masking tape. Which is brittle and falling apart.

But in any case, we bought this boat specifically to turn it into a comfy living boat for two people. It started with four cabins, and will have only one when we're done. So we decide early on that we don't give a flying flip about the resale value. Someone else will either appreciate it as a modified two person boat, or they'll strip it and re-do it the way they want to. There's only about a dozen of these left, it'll sell should we ever want to. If it doesn't sell we'll donate it to something.

I plan to eventually get the mast rewired if I ever get to a place where there's a boatyard that can do it. In the meantime, down here deep in the Land of MakeDo....

[rwidman]

Originally Posted by Canibul

Yeah, that's pretty much my thinking on it, copper is copper. Electrons don't stop to examine receipts to make sure where it was purchased or when. Doesn't matter if it's old copper or new copper, long as it's still copper.

Re the resale, the truth is that if I duct taped lamp cord to the mast it would be an improvement over some of the wiring the three previous owners made. I am finding stuff that astounds me. Yesterday I discovered that I have an ac outlet under my inside helm station in which the wires ( orange extension cord) are twisted together and insulated with paper masking tape. Which is brittle and falling apart.

But in any case, we bought this boat specifically to turn it into a comfy living boat for two people. It started with four cabins, and will have only one when we're done. So we decide early on that we don't give a flying flip about the resale value. Someone else will either appreciate it as a modified two person boat, or they'll strip it and re-do it the way they want to. There's only about a dozen of these left, it'll sell should we ever want to. If it doesn't sell we'll donate it to something.

I plan to eventually get the mast rewired if I ever get to a place where there's a boatyard that can do it. In the meantime, down here deep in the Land of MakeDo....

I it meets your standards, do it. Read my cautions in my first post. Even if you're not concerned about resale value, an electrical fire on your boat can be a problem.

[DeepFrz]

After your last post I am wondering what the purpose of the thread was.

[dpddj]

Let Dooley figure it out.

[Canibul]

Originally Posted by DeepFrz

After your last post I am wondering what the purpose of the thread was.

I had a question, as stated, "Is there any reason I shouldn't triple up six of those into two pair for the light, and use a couple of the others for the speaker? " This was the purpose of the thread. I tried to make it clear in the title, as well. So that people who were not interested specifically in reusing radar cables could just skip on by to better things. How is that confusing?

I couldn't think of any reasons it wouldn't be okay, but thought I'd ask just to see if there was something I wasn't considering. That happens all the time.

The subject of resale was not a part of the purpose of the thread.