Installing a wind sensor

[Bodach na mara]

I have just splashed out on a NASA Clipper wind system to replace my old Autonic one. (Please don't post to tell me what a mistake that was as I have just read other posts on the subject.) The problem now is how to install it. The wind sensor comes with a 20 m cable which is wired in to the head unit and fitted with a moulded-on plug. The instructions say DO NOT CUT THE CABLE!

Now, how do you feed the cable (with plug) down the conduit inside the mast (or worse, feed the masthead assembly up the mast and out the wee hole at the top. No, forget I said that last bit.) Then, the mast comes down each year, so I need some sort of disconnector at the mast foot to allow this. Where can I get one? It needs five terminals as far as I can see.

Obviously lots of you have these things installed, so please, how did you do it?

 

[wcarpenter]

I put in a NASA wind system in a few years ago and had the same problem. What I did was unsoldered the connections at the mast head and then pulled in the cable resoldering when complete. If your old system is still in place cut the cable at the mast head tie some strong string to it and pull it down. then tie the new cable and pull it up.

 

[SvenglishTommy]

I have the same issue with the Silva wind system I just bought. I am going to cut the cable at the bottom of the mast and fit a 4 pin plug/socket. My (keel stepped) mast comes down every year too, so I dont really see any other alternative. My manual does not mention anything about cutting the wire though.

 

[slimted]

Just bought the same unit, I would be intersted to know what you end up doing. I was planning to install a plug/socket as above but worried about cutting cable.

Ted

 

[jimg]

Not sure about Nasa, but Raymarine say the same. When I had a problem with the mast head unit, the engineer cut the old cable and joined the old run with the new and I have had no problems!

 

[kieronriley]

if its like mine which i,m sure they only make one its just a five pin din plug so i went to a hi fi shop and got an extension lead five pin din femail to five pin din male and added it in to the length and then just leave it connected all the time plenty of length even with the mast down and if you have to disconect its easy just unplug and would agree to diconect mast top unit to install its easier to solder than a din plug(but wait for a warm day or the soldering is blo.dy very hard to do)

 

[Avalon]

When I installed a NASA Clipper wind system, I cut the cable, and routed the signal though the old B&G cable to the NASA 5-pin DIN connector, using connecting blocks at each end. Worked perfectly. Main problem was that the NASA masthead units disintegrate after a couple of years. Now replacing with a Cetrek instrument to match my others (which uses an Autonnic masthead unit)....

Don't worry about cutting the cable - it'll be the least of your problems!

 

[lumphammer]

As with previous answers I opened head unit and unsoldered wires, then pulled cable up mast and re-soldered at the top.

Make a note of the wire colours and don't do what I did which was to identify my sketch with Wh, Rd, Bl and Bl (for blue and black) - great embarassment when I couldn't remember which was which.

I take cable through deck and cut it just inside. I have crimped terminals on the wires and fix to a terminal strip. Seems to work so far.

 

[Metabarca]

Dogwatch kindly provided a comprehensive and fully-illustrated reply for this probelm some time ago on the forum, which I am myself about to put into practice. I can't find it now but a search should dig it out for you. The long and the short of it is: cutting the cable was no problem re the functioning of the unit.

 

[hubert]

I had the same problem and phoned NASA they said it's ok to cut the cable as long as it is properly connected.

Cut the cable where it is most convenient. (preferably where the joint can be kept dry.) Strip back a good length ( About 3 inches.... don't try to work with fiddly short lenghts.) Join the wires colour to colour in a terminal block or solder and insulation. Don't forget the screen wire. There are four coloured wires and the screen wire, all are needed. You can shorten or lengthen the cable as neccesary. The wires are quite thin so a little care is needed.
If you have a problem then this will help to locate it:-

If plugging in the masthead turns off the display then the red wire is shorted to the screen.
If you have lost both wind speed and direction then the red or screen are open circuit.
If you have lost the speed only then the white wire is shorted to screen or open circuit.
If direction is missing in two quadrants then the blue or black is open circuit.

Quite simple really.

 

[Bodach na mara]

Thanks for all the help. I also used NASA contact service and they also suggested feeding the cut end through a gland to a terminal block below deck.

The only reason I don't want to do that is that I get the mast taken down eacy year. If I forget to undo the joints and withdraw the cable from the gland, the local boatyard have a handy Rapid Cable Disconnection Tool that they use. Wire cutters!