Author Topic: Help with Davis Vantage Pro2 anemometer  (Read 2974 times)

0 Members and 1 Guest are viewing this topic.

Offline KenD

  • Weather Underground
  • Member
  • *
  • Posts: 40
Help with Davis Vantage Pro2 anemometer
« on: January 18, 2012, 08:34:40 AM »
My Davis Vantage Pro2 weather station has been working flawlessly since I set it up two years ago.  This morning I noticed that my anemometer readings are cycling between 0 and 1 mph.  Looking at my history on Weather Underground, it appears that the problem started at 10:30 last night.  I checked my console and it appears that the wind direction is behaving normally but the speed is cycling between 0 and 1 mph.  Neighboring stations on Weather Underground are showing wind speeds in the past few hours that seem appropriate for the conditions.  My anemometer is mounted high on my roof with a remote box on the side of the house so I replaced the battery in the remote unit but I'm still getting the anomalous wind speed readings.  Any suggestions on what I can do to troubleshoot the issue?  Getting to the anemometer itself is a bit of an issue since it's at the very top of my two story house and the roof has a severe pitch.  I paid someone to mount it for me since I was too much of wimp to get up there myself.  :)

        KGALILBU8/DW4380

Offline d_l

  • Forecaster
  • *****
  • Posts: 1654
  • Slide Mtn - Mt Rose
    • Thomas Creek Estates Weather
Re: Help with Davis Vantage Pro2 anemometer
« Reply #1 on: January 18, 2012, 08:59:02 AM »
Unplug and replug the RJ12 plug into your anemometer transmitter to be sure there is a good connection there.  That's about all you can do without getting up on your roof.

It is possible that your anemometer cups are slipping or have slid down slightly on the shaft.  That would be the next thing to be checked.

If the set screw is tight on the cups and the cup's hub is up on the shaft as far as it will go, then your reed switch may be failing.

This accessibility problem for maintenance is one of the reasons why I've soured on roof or gable mounts and decided to use a flag pole mount intead.
--Dave--

Wireless VP2 w/ solar, 24hr FARS, Heater, (Envoy-WLIP)*2-Meteohub, plus custom VP2 @ 26', WL 6.0.0, WU & W4U=KNVRENO37 NetcamXL

People always talk about the weather, but they never do anything about it.  Not me.  I'm gonna measure it.  www.tceweather.com

Offline bro931

  • Member
  • *
  • Posts: 9
Re: Help with Davis Vantage Pro2 anemometer
« Reply #2 on: January 18, 2012, 03:29:06 PM »
I had a similar problem with my anemometer last summer.  It was reading dead zero for three days straight.  But the winds were unusually light during that time.  I checked the vanes a number of times and they were indeed motionless each time.  Finally, we got some wind again and the first non-zero reading was about 5 mph.  I suspect that the vanes may have become entwined in something (spider web?) during a long period of actual calm.  It took a good wind to free everything.  No problems since.

Offline 4wd

  • Forecaster
  • *****
  • Posts: 363
    • North York Moors weather
Re: Help with Davis Vantage Pro2 anemometer
« Reply #3 on: January 18, 2012, 04:36:54 PM »
They always fail in the middle of winter or during a wet period, so here too I've compromised ideal height for easier maintenance and just have it on a long pole I can lower by undoing two bolts.
The worst thing is that 'temptation' to try to access the roof mount when conditions are borderline, plus we're all getting that bit older and what might've been OK five years ago is that bit more risky now  :-P

Offline KenD

  • Weather Underground
  • Member
  • *
  • Posts: 40
Re: Help with Davis Vantage Pro2 anemometer
« Reply #4 on: January 18, 2012, 05:22:38 PM »
Ugh, my wind speed is still flatlining after replacing the battery and reseating the RJ12 plug.  Looks like I'll have to get my guy to bring down the anemometer so I can check the set screws and the reed switch.  And I was just telling my wife that out if all my tech gizmos, I dreaded a failure of the anemometer the most.  :(

        KGALILBU8/DW4380

Offline KenD

  • Weather Underground
  • Member
  • *
  • Posts: 40
Re: Help with Davis Vantage Pro2 anemometer
« Reply #5 on: January 31, 2012, 06:58:00 PM »
While I was waiting for my guy to come over and get up on the roof, I noticed that I started getting wind speed data around the 26th.  I've been getting wind direction all along, it was just the wind speed that was cycling between 0 and 1 mph.  Today, he came over and tightened the set screws on the wind cups but he said they weren't that loose and obviously that wasn't the issue since I had been getting wind speed data.  Any ideas on what was going on?  I had him check the cable running to the remote for breaks and he didn't find anything.  Water somewhere shorting a connection maybe? 

        KGALILBU8/DW4380

Offline dalecoy

  • Forecaster
  • *****
  • Posts: 4271
    • Lee's Summit, MO
Re: Help with Davis Vantage Pro2 anemometer
« Reply #6 on: January 31, 2012, 07:01:19 PM »
While I was waiting for my guy to come over and get up on the roof, I noticed that I started getting wind speed data around the 26th.  I've been getting wind direction all along, it was just the wind speed that was cycling between 0 and 1 mph.  Today, he came over and tightened the set screws on the wind cups but he said they weren't that loose and obviously that wasn't the issue since I had been getting wind speed data.  Any ideas on what was going on?  I had him check the cable running to the remote for breaks and he didn't find anything.  Water somewhere shorting a connection maybe? 

Did he just tighten the setscrew?  Or did he first loosen it and then move the cup assembly as far up as possible?  Sometimes, the distance between the magnet and the reed switch is "marginal".

Offline KenD

  • Weather Underground
  • Member
  • *
  • Posts: 40
Re: Help with Davis Vantage Pro2 anemometer
« Reply #7 on: January 31, 2012, 07:17:53 PM »
No, he didn't loosen it first.  I wasn't home when he came.  But he said he pulled down on the cups and they didn't move so he tightened the set screw and said he only got maybe an eighth of a turn.  Seems to still be working although winds are calm now.
« Last Edit: January 31, 2012, 07:19:47 PM by KenD »

        KGALILBU8/DW4380

Offline dalecoy

  • Forecaster
  • *****
  • Posts: 4271
    • Lee's Summit, MO
Re: Help with Davis Vantage Pro2 anemometer
« Reply #8 on: January 31, 2012, 09:20:57 PM »
No, he didn't loosen it first.  I wasn't home when he came.  But he said he pulled down on the cups and they didn't move so he tightened the set screw and said he only got maybe an eighth of a turn.  Seems to still be working although winds are calm now.

Sounds like all the pieces are OK, and maybe it will keep working. 

If it fails again, have him remove the cups and then do the install procedure called for in pages 3 and 4 of the ISS manual.

Offline therock64

  • Member
  • *
  • Posts: 39
    • St. John's Newfoundland Weather
Re: Help with Davis Vantage Pro2 anemometer
« Reply #9 on: February 01, 2012, 02:01:42 PM »
I had the same problem last year during a storm. The cups were moving, but no measurment.. I did the same as the guys said here. Had to take the part off completely and re-set it back in. Seems to have moved down a small bit during the wind. (122 Km/h) When i checked it first it did not move down any, but after taking off the set screw it went back up about 1/8". That did the job...
Good luck... :grin:
Gary Woodman
St. John's, NF Canada
Davis VP2 6152 wireless
Weather from "DA ROCK"


Offline AVman

  • Member
  • *
  • Posts: 6
Re: Help with Davis Vantage Pro2 anemometer
« Reply #10 on: April 20, 2012, 05:22:18 PM »
My 2 cents: I have a VP1 and after more playing than it should have taken, I noticed the magnet for the anemometer is in the cup assembly, and the reed switch is in the holder/base thing.  This would mean if the cups dropped just a little too much the magnet would trip the reed switch every once and a while, generating strangely low readings. Pushing the cups up should solve this, but for a more permanent solution it seems you could push the magnet up and epoxy it closer to the reed switch.
I hope it yours keeps working!

Offline johnd

  • Forecaster
  • *****
  • Posts: 1527
    • www.weatherstations.co.uk
Re: Help with Davis Vantage Pro2 anemometer
« Reply #11 on: April 21, 2012, 03:50:31 AM »
This would mean if the cups dropped just a little too much the magnet would trip the reed switch every once and a while, generating strangely low readings. Pushing the cups up should solve this, but for a more permanent solution it seems you could push the magnet up and epoxy it closer to the reed switch.
Actually, the cups dropping is very rarely a problem (except occasionally in new installations where the cups might not have been tightened sufficiently in the first place).

What is much more likely to give these symptoms is that the reed switch is starting to become faulty, but is at the stage where even a slight mechanical disturbance can unstick the contacts and allow the anemometer to start working normally again for a period. The simple act of adjusting the cups can cause sufficient mechnical disturbance to have the effect of restoring the wind speed for a time, maybe even weeks or months.
Prodata Weather Systems
UK Davis Premier Dealer - All Davis stations, accessories and spares
Littleport, Ely, Cambs UK

Offline d_l

  • Forecaster
  • *****
  • Posts: 1654
  • Slide Mtn - Mt Rose
    • Thomas Creek Estates Weather
Re: Help with Davis Vantage Pro2 anemometer
« Reply #12 on: April 21, 2012, 10:32:04 AM »
Actually, the cups dropping is very rarely a problem (except occasionally in new installations where the cups might not have been tightened sufficiently in the first place).

What is much more likely to give these symptoms is that the reed switch is starting to become faulty, but is at the stage where even a slight mechanical disturbance can unstick the contacts and allow the anemometer to start working normally again for a period. The simple act of adjusting the cups can cause sufficient mechnical disturbance to have the effect of restoring the wind speed for a time, maybe even weeks or months.

To add to what John has said if you call or email Davis, they will tell you to check the position of the cups on the shaft.  Often if you loosen and reassemble the cups on the shaft, you can get a failing reed switch to work again temporarily, BUT unless you want the chance of pulling your anemometer down again after a short time period, don't trust your "repair" job.

You can often prove the short lifespan of your "repairs" to yourself if your hearing isn't shot by listening closely to the anemometer as you spin it.  The reed switch opening and closing sounds like a faint cricket chirp.  Try both ears as your hearing in one might be better than the other.  Once you hear your anemometer, try buffeting the cups by bumping them up and down.  A failing reed switch will often stop chirping after such treatment.  This test can convince you to replace the anemometer rather than risk a repeat failure after it is remounted.
--Dave--

Wireless VP2 w/ solar, 24hr FARS, Heater, (Envoy-WLIP)*2-Meteohub, plus custom VP2 @ 26', WL 6.0.0, WU & W4U=KNVRENO37 NetcamXL

People always talk about the weather, but they never do anything about it.  Not me.  I'm gonna measure it.  www.tceweather.com