Raymarine - Bad TWS Reading

Vladis

Vladis

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Hello,

During this winter maintenance I repaired the connection near the mast of the multiwire cable that brings data from the wind transducer. It was the 8 volt wire that was interrupted. My system is a Raymarine SeatalkNG as depicted here:

http://www.vela-navega.com/forum/viewtopic.php?f=2&t=44

As soon as I fixed the connection I got wind data again in the instruments. However the boat went to the water 2 weeks ago and I am noticing a strange malfunction. It is erratic. Some times the error appears sometimes it does not. The error is that when wind speed is low the TWS freezes and is precisely equal in value to the Speed Through Water. And, when it happens, the True Wind Angle is exactly the direction from behind the boat. This never happens when TWS is greater than, say, 10 knots. As soon the wind increases it looks like the system works perfectly. I set SOG and STW as the reference to evaluate the TWS but got no difference. Any feedback is much appreciated.

Regards Luis
 
Are the wind speed cups still turning when this happens? Sounds like it is reading zero apparent wind so true wind must be equal to boat speed and in the same direction as boat course.
 
Hello,
Yes they are turning. I am just sailing from Zakinthos to Kiparissia with COG about 130 degrees with error On. I turned back to 310 degrees and the the reading started to work showing about 9 knots from North.

Regards and Thanks, Luis
 
Hello,

AWA is always right. AWS shows 0 when the error is On. I just measured the voltage at the yellow wire when it reaches the box/pod (that converts to seatalk) and I get a varying voltage of between 3.8 to 4.1 volts which looks compatible (?) with the the apparent wind speed of 3 to 4 knots (what I just got in a time that the error was Off). I need the help of another person to check if the error is On or Off while I measure the voltage (locations are apart). I start to think that the problem is in the Pod. The first one failed after 5 years. This one has 3 years from new.

Regards and Thanks, Luis
 
What type of pod do you have?
The old pod has gone out of production, according to my sources because they where unreliable.
it seems that they only sell the ITC-5 today
 
Hello,

Yes. When I tried to buy a replacement pod 3 or 4 years ago, only the itc-5 was available. But I got a supplier that had the old pod in stock and I bought it.

I think that during the next winter I will try to make circuit to convert the analogue voltages from the wind sensor into SeatalkNG data.

Regards Luis
 
Hello,

I am convinced that I have to replace the cable that brings data from the wind transducer to the base of the mast.

Today my wife was looking to the chartplotter showing AWS = 0 while I was in a odd position near the wind pod measuring the "speed voltage". It was almost constant equal to 4V.

Then I went to the mast base and when I was gently pulling the several cables that come out at the base (radar, antenna, lights,..) my wife shouted - "it is not zero!". I returned to the pod and now the voltage was clearly varying between 2 and 3 volts.

The cable was accidentally cut in the past near the base of the mast and my repairs with soldering and tube shrinking seem not to work. If someone knows the exact cable reference I would be grateful to know.

Regards and Thanks, Luis
 
I think you will find that the cable is moulded into the block at the top of the mast so you won't be able to re-wire it completely. But if you can cut it back to undamaged cable it should be easy enough to repair with solder and heat-shrink. After all the joint at the mast base is made with simple terminal blocks.
 
Hello,

Thank you for that important information. The original cable when I pull it out at the Base of the mast comes out about 20 cm which is a small length to make a proper joint. Could I pull it out from the top of mast (with a guide line for reinserting) and make a good and solid join with an extra length of cable and then pull the guide line to place the cable again inside the mast? Or the moulding to the block that you refer to does not allow me to follow that approach?

Thanks, Luis
 
Vladis said:
Hello,

Thank you for that important information. The original cable when I pull it out at the Base of the mast comes out about 20 cm which is a small length to make a proper joint. Could I pull it out from the top of mast (with a guide line for reinserting) and make a good and solid join with an extra length of cable and then pull the guide line to place the cable again inside the mast? Or the moulding to the block that you refer to does not allow me to follow that approach?

Thanks, Luis
Click to expand...

If your cable runs freely inside the mast then that is a possibility. You could pull it out of the mast and take it home to make a good joint then pull it back in. But if the joint is too fat it might snag on something inside the mast. The cable and the moulded block look like this:-

NAA28162JPG1100.jpg


https://www.foxschandlery.com/raymarine-30m-wind-cable-and-connector-a28162?gclid=Cj0KCQjwzunmBRDsARIsAGrt4mskkqoEuMWW4DkSZJ2ghE5X6vx4XFU-Ja4A9GWFtLKm26RvtKnI36IaAjmhEALw_wcB

The wind vane unit plugs into the block and is secured with a nut. So you could just replace the block and cable with new and plug the vane into the new block. Not cheap but nor are any Raymarine cables in my experience.

Are you sure that the wind speed cups are rotating when it is reading zero apparent wind? If they are sticking at low wind speeds that would give the same effect and replacing the cable won't help!
 
Hello,

Thank you very much. I found also that cable that you show in the picture. Since I examined the join the reading never failed. It is very strange for me to understand what could trigger the off/on as there was no apparent movement of the cable. I think I should take an action. You just gave me an idea as an alternative to mount the whole system shown in your picture. As the joint can be pulled out of the mast base some 20cm, I can connect a guiding wire which will move freely inside. So I could remove the present moulded assembly at the top of the mast, bring it home, cut 2 metres of wire so that the join will become higher from the Base and inside, and make a very professional joining to an extra 3 metres of new cable, using soldering and tube shrinking. I have these know but the shield is very brown (oxide) and difficult to join.

Regards and thank you for your great feedback! Luis
 
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