Sunday, August 1, 2010

Stick your hand in the job jar, and pull out a couple boat improvement projects.


The owner of this boat had the feeling that the equipment in his console was getting to hot, and I agreed that the top of the console felt warmer than it should. I suggested that maybe a computer cooling fan would do the trick.

There was an existing Beckson-esque plate that I had installed on the side of the console, to allow access to see the happy, or unhappy status lights of the black boxes that had been installed inside, and also to facilitate removal/installation of the bolted in displays. The owner did not want another hole cut into the console, so mounting the fan on the access plate seemed to be the best option. These little fans are very quiet, move a lot of air, and are available in both 12VDC, and with a small transformer, 110VAC. The owner went to a local store, and picked up the one you see here

Installation is as simple, or complex as you want to make it. The back of the mounting plate had molded in stiffening webs, so in order to mount the fan on the inside of the plate, some considerable carving would have been required, so it was mounted on the outside, and it looks good, in a form follows function kind of way. 

These fans often have hologram images on the hubs, which makes for cool looking patterns when they are running. It could have been done in a more elegant fashion, given more time and money, but the owner said it was fine, there are other more important things to do.

A couple of quick notes about these fans. Make sure you are buying a 12VDC fan. Some of these fans can vary their speeds, so when you look at the wires, and there might be up to five, just look for the red and black wires, and ignore the rest. When you install the fan, it is a good idea to take some silicon, or hot glue, and well secure the fan wires. They are small gauge, and can pull away from the fan, if you are not careful. I know from personal experience, that re-soldering a broken lead requires no coffee for two weeks prior, and a magnifying glass.

















In the picture below, you are looking down at a generator, with the covers removed. The generator lives in a compartment accessible from the deck, and like most spaces used on a boat, it justs fits in the space, which translates to access is less than optimum.

So here is the problem. In the picture below, where I wrote "Under here", lives a capacitor that fails more often than it should. This means that several times a year, always at the worst possible time, on the hottest day of the year, on a out island in the Bahamas, it craps out. Why, I don't know, it could last a week, or six months, but it will fail, and the manufacturer just shrugs his shoulders, and says the equivalent of "I dunno." I bet these guys sell a ton of these capacitors, because the repair technicians always have them on their truck, always. 

To change this capacitor, you first remove the generator covers. You then get several towels to lay on top of the generator, because it is stinking hot after running for days. Laying down on top of the unit, you reach under the black back end of the generator, and with a socket wrench, while trying to keep from being burnt, you release the bolt that holds it in place. You have to do this in what I call "Braille" mode, because you certainly can't see it. Once the bolt is off, you then cut two wire ties to release it. The wires are about three inches long. Taking a screw driver, you discharge the capacitor by shorting the contacts (this is always exciting to someone watching), not so much for the person doing it. You pull the connectors off, plug in the new capacitor, and reverse the process to finish. Under the best of circumstances, this is not fun, and under the worst circumstances it is a  #&!%^* awful job.

















I know that the designers of this generator, have never changed the capacitor on an installed generator, or it would have never been placed where it is. It looked good on paper, but it was a bad idea in real life. The fix is not hard. See the red and black wires coming out from where I wrote "Under here?" These are the new capacitor leads. They exit the enclosure and go to the new capacitor mounting location on the underside of the hatch. So to change the capacitor now, you just open the hatch, and there it is, and while the phone lines were still open, he got the bonus of a second capacitor holder to boot, but no free Sham Wows. I know the capacitor will fail, and I mounted a second holder next to the first. To change the capacitor, just open the hatch, unplug the bad one, and plug in the new one right next door, and you are finished in sixty seconds or less. The second capacitor in the photo is actually a failed one, but two new ones are coming, (history tells us they will be needed) and some split loom now covers the exposed wires. The clamps were $4, from a local hardware store, and are really for conduits, but they work a treat.

2 comments:

  1. And you can find cooling fans of this sort in all sorts of shapes, sizes and voltages. But as with your capacitor, get a couple, because they will fail sometime.

    http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1179730&k=cooling%20fan

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  2. Thanks for the comment Robert, and the comments and assistance with the autopilot. You are right about failure, the boat will have three capacitors on board next week, and I will order a back up fan, Thanks Bill

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