Topic: VP2 Anemometer

[raldridge]

My anemometer has started not working over night in regards to wind direction?. The wind speed is working
properly but not the wind direction.
Has anyone got any idea what would be causing the wind direction to fail at night it just freezes at NNW 335°
I have re-calibrated the anemometer 25° to the west as I am unable to site the anemometer arm to true north.
It started  recording the wind direction at about 10°C between 9 and 10am today and stopped giving the wind direction at about 5pm today while the outside temperature was 12°C.

[miraculon]

Is this anemometer connected to an ISS, or to a 6332 Anemometer Transmitter?

If ISS, are the other sensors working all night?

Does NNW 335° correspond to the mechanical "N" direction of the windset arm?

If there is an electrical problem with the wind set wiring that affects the direction, it typically will go to North.

See this guide for troubleshooting advice: http://www.wxforum.net/wxtech/Anemometer-Vane.htm

Note these items:

Wiring errors:
yellow wire open causes a north indication
green wire open causes a north indication
red wire open causes a north indication and prevents wind speed from being indicated
black wire open prevents wind speed to be indicated
yellow to green shorted causes a north indication
yellow to red shorted causes a north indication
green to red shorted causes a north indication
black to yellow shorted, wind speed zero
black to green shorted, wind speed zero and direction erratic
black to red shorted, wind speed zero, intermittent short causes wind speed error

Greg H.

[Mattk]

Sounds more like a short or moisture affecting the wind direction circuit?

[raldridge]

My ISS is wireless version and the wind cable is connected by a plug into the SIM transmission box.
Yes everything else is working overnight including the wind speed.
There could be a problem here in regards to my re-calibration from 360° to 335° as I did not check or have the vane
pointing north at setting up of my ISS in the first place in October 2017.

Do not forget this is happening only over night. lately it is happening when the UV sensor is in 0.0 index position as we are not far from the shortest day or winter. The wind direction is working fine now as it is day time.
But I bet when the UV sensor index goes to 0.0 index the wind direction would have stopped working again?.

Also if it is a wiring fault why would the wiring be effected only at night and not during the day?.

[CW2274]

Is it reasonably easy for you to bring the anemometer down so you can "fiddle" with it while simultaneously looking at your console? You need to start trouble shooting and the anny vane itself is the place to start.

[raldridge]

The way I have the outside part of my ISS installed on the fence it is not easy to bring the anemometer down
without assistance from my next door neighbour, who has tools that are needed plus a ladder.
As you might have gathered I am not a DIY type person, I would rather pay someone skilled in this area like an
electrician who could check out the wiring to see why  it is only effected at night time.

As it is night time problem I do not see what difference re-calibrating the anemometer would have in fixing the
problem I am having?. 

[CW2274]

I do not see what difference re-calibrating the anemometer would have in fixing the problem I am having?.

Yeah, that's not it.

[raldridge]

After talking to a friend about this he has suggested that it could be power problem.
As I have to have the SIM transmission box facing to my yard which is facing away from the sun so I have access
to the SIM box for maintenance, which is possibly causing a lack of power so its not getting enough power from the sun to run all the ISS sensors at night. Not that we get much sun this time of the year anyway.

My friend suggested contacting Davis Instruments to see if my wireless version can be converted to a cabled
version. But before permanently installing test to see if this fixes the problem?.

[johnd]

If it was a low SIM battery or eg a pending supercap issue (which I think is what you're suggesting) then it would affect all sensor readings equally. So if ALL readings except wind direction are updating correctly then it's not a 'power' issue.

The most likely alternative cause of wind direction issues overnight (as has already been suggested) is either dew/moisture getting into the cable/plug etc somehow or possibly a temperature-dependent issue in SIM board or anemometer - I'd suspect the latter, but impossible to know for sure until you swap out the part.

[Mattk]

Based on the description of the problem this issue would exist be it a wireless or cabled system, this wouldn't be a conversion but a complete replacement and don't see any purpose in doing this.

One way to check if it is a power issue (which it probably isn't) is to run the ISS direct on DC power, 4.5-6volts using a 2.1mm DC plug, however I doubt this will change anything?

Doubt this will fix the issue either but you could try replacing the modular 6P4C plug, however from all comments it does appear environmental related (humidity, temp, dew point etc?). Also simple enough to remove the wind vane, especially if a "D" shaft version and check for moisture etc

[CW2274]

Also simple enough to remove the wind vane, especially if a "D" shaft version and check for moisture etc

Yep. This would be the first thing I'd do and give it a good CRC cleaning. Probably won't help, but gotta start somewhere.

[raldridge]

I had to get an electrician to install a new light for my living room, so thought I would ask him to fit a new RJ/11 plug to the wind cable which he did, but as he said he thought that this would not fix my problem, as it turned out the electrician was  correct. The people at Davis Australia asked me, did you make sure that the reverse polarity was matched?. What ever that means?.

[miraculon]

The people at Davis Australia asked me, did you make sure that the reverse polarity was matched?. What ever that means?

Davis uses a "straight through" pinout for their cables. Telephone wires reverse them at one end. This is why you can't use a telephone cable in lieu of the correct one.

See my previous post regarding rain gauge connections here: https://www.wxforum.net/index.php?topic=39042.msg401460#msg401460 The same issue exists for the anemometer.

Greg H.

[raldridge]

I am sorry but that is as clear as mud to me, as I am not an electrician.
Would a new anemometer fix this problem it seems I am unable to solve?.
Would it fix this reverse polarity thing that Davis is speaking of?.
The wind direction is working now as the temperature is above 14°C at 16°C  at the moment  at 10.20am

[raldridge]

A more curious thing has happened in the last 2 days.
If the temperature now drops below 12°C it is starting to record the wind direction and last night when the low was down to 2°C which is pretty low for us in this island state of Tasmania.
I could not believe my eyes when the anemometer was still recording the wind direction.
When I went to bed last night about midnight the outside temperature was down to 3°C and it was still recording the wind direction then. We had light frost over night. But the winds were very light flicking between 0 and 1mph.
At the moment the temp. is down to 8°C at 10pm. forecast low is 7°C and it is still recording the direction.
I cannot explain this complete turn-around.
I have ordered and paid for a new anemometer from Davis Australia hoping that would fix the problem, but they are out of stock at the moment and do not expect a new shipment until about the middle of June this year.
Will be interesting to see if it records the direction during the day tomorrow?.

[Mattk]

Would a new anemometer fix this problem it seems I am unable to solve?.

Possibility?

Would it fix this reverse polarity thing that Davis is speaking of?

You mean the way the electrician may have fitted the modular connector? Only if the electrician fitted it the wrong way around.

You can check this by looking that the modular plug, with the flat anemometer cable held in front of you and the tab/lock of the plug on the underside as you hold it, the Black wire should be on the right, with the colours to the left being Yellow, Green, Red, Black, in that order to the left
   

[Mattk]

The thing you are seeing with low temperature is not really related to the temperature but more like Humidity, Dew point which are related to temperature. Take more notice of the humidity and dew point when the wind data changes

[johnd]

Would a new anemometer fix this problem it seems I am unable to solve?.

Probably, but no-one can tell for sure in advance. This sounds like an odd and unusual issue that doesn't have any well-known or easily-pinpointed cause, and which as mattk suggests isn't helped by the fact that it doesn't seem to happen continuously but only under conditions of higher humidity.

There are some missing pieces to this fault report. Eg where are you seeing that the wind direction freezes - on the console display or on software. What sort of wind speed readings are you seeing when the direction freezes - presumably they are non-zero readings? And I can't help wondering whether the direction offset is a factor - what happens if you remove the offset - is the issue still there, albeit perhaps freezing at a different direction?

But other than these points and assuming that the cable and plug check out OK then there are only two possible causes - a faulty wind direction pot in the anemometer or some faulty circuitry on the wind input of the SIM board. Neither of these can be easily fixed as a repair by a general user and the only pragmatic solution is a replacement part, starting with the anemometer since that's the more likely to be at fault.

[raldridge]

Well further to my last message the anemometer is still displaying wind direction and seems now to be doing  this all the time. How this happened I do not know it just started working by itself as I have not touched it in weeks.
The humidity outside has just now gone from 80% to 81%. The high humidity does not seem to bother it now.

Will be interesting to see what happens when it rains?. The barometer is fairly high at present at 3026 inches in the
dry area, so not much chance of rain for a while?.
As I think I informed you I had a new SIM box installed weeks ago and an electrician crimped a new plug on the end
wind cable, so whether this made any difference I do know, if it did it took a long time to work properly after this.

It started working about 3 days ago when it was a very cold night, this might have made it work.
If so what will happen in the summer when we get very hot dry weather again?. 

[raldridge]

I have fixed the problem I was having with wind direction by purchasing a new anemometer, now installed
is working perfectly. So the problem was related to the original anemometer. I still do not know what was causing
the previous anemometer to not show the wind direction all the time?.

[gsfarm]

@raldridge
I have had issues with my anemometer in the past where there was a bad connection at the ISS where the modular plug plugs into the circuit board. Plugging and unplugging the connector a few times might make it work for a while sometimes, but eventually I installed a new connector to fix the problem. Seems the contacts on the anemometer side of the connector corrode over time. I could actually see rust inside the connector where the contacts are crimped to the wires.
You mention you are on an island, likely not far from salt water, where salt can get carried in the wind and moist air for quite a distance... maybe a bit of silicone grease pushed into the back of the anemometer connector might help just to repel moisture on your new unit.

I also have an older original VP with original anemometer, cable, etc. It has never corroded. Must be a better connector. I am actually using it on my VP2 right now since my anemometer bearings ceased a vew months ago on the VP2 anemometer. Waiting for the new bearing cartridge to arrive...

Glad to hear you have your station up and running again!
-G.

[raldridge]

How long did it take for your bearings to wear out, as this might be an indication as to how long mine might last also?. I am guessing the bearing that wore out was for the wind speed cups and not the wind direction vane?.

[gsfarm]

I have changed them once already, the unit is coming up on 3 years old. We get a lot of high winds here and cold winters, I suspect the bearings are designed for more temperate climates and wear quicker in the -30C/50+km winds. They both quit in the depths of winter (basically ceased bearings).
The original VP anemometer must have been designed for a wider range of climate, it is still going strong, even though something broke one of the cups off the spinner, which was not a big deal to replace.
Good to have a spare in case, the part# is 7345.953 I think for the VP2 cartridge. This is just for the anemometer, not wind direction indicator part.
Cheers,
-G.