Topic: Confusion with DFARS

[plex]

Hello

The mail just came with my first Davis station - VP2 wireless sensor suite, wireless anemometer transmitter and daytime FARS.

The manual is confusing, cause some pictures shows 5 rings under the fan ring, and others 6 rings. I only managed to install 5 rings - 2 closed in the bottom, and 3 open. I still have one closed left, and the bolts is not long enough for another closed one - but what can another closed one achieve to the setup?

Also pictures from internet shows both version - 5 and 6 rings.

Is older versions with 6 rings, or what is the explanation.

Thanks

5 rings - mine looks like this now


6 rings

[ValentineWeather]

If it came with 6 plates, I would double check instructions and make sure all plates are aligned correctly.

[plex]

If it came with 6 plates, I would double check instructions and make sure all plates are aligned correctly.

I'm pretty sure plates are correct aligned

The best picture/exploded view from manual, has only 5 plates, however other illustrations has 6.

The kit comes with 4 plates, and the rest is from the original shield.

Hrmm I guess everything is correct

[plex]

Just the answer my own question.

I asked Davis, and 5 rings is for DFARS, and 6 rings are for 24 hour FARS.

[George Richardson]

plex,

The instructions for the DFARS ARE confusing. However, I do think that Davis gave you some bad information. The naturally aspirated VP2 has 5 shield plates which the instructions say to modify (remove the insulating disk) then rearrange position, then ADD a 6th "open plate". This can be deciphered in the section, "Assemble the Lower Section" of the installation manual (page 6 in mine). FWIW, I have 3 VP2 DEFARs and all are assembled with 6 lower plates. I have 1 VP2 with 24hr FARS and it has 7 lower plates. So, to summarize, 5 rings for naturally aspirated, 6 rings for DFARS, and 7 rings for 24 hr FARS.

[plex]

plex,

The instructions for the DFARS ARE confusing. However, I do think that Davis gave you some bad information. The naturally aspirated VP2 has 5 shield plates which the instructions say to modify (remove the insulating disk) then rearrange position, then ADD a 6th "open plate". This can be deciphered in the section, "Assemble the Lower Section" of the installation manual (page 6 in mine). FWIW, I have 3 VP2 DEFARs and all are assembled with 6 lower plates. I have 1 VP2 with 24hr FARS and it has 7 lower plates. So, to summarize, 5 rings for naturally aspirated, 6 rings for DFARS, and 7 rings for 24 hr FARS.

Hello George

I did like illustration on page 8 in my manual:
http://www.davisnet.com/product_documents/weather/manuals/07395-236_IM_07747.pdf

What I have left, is the old closed ring, with the isolation disc.

I can't see where I could add this, since another closed plate doesn't make any difference. And my bolts are not long enough to cary one more ring.

Mine looks like the first picture in my first post - 5 rings under the fan ring.

Totally confusion here

Here's what Davis technical support told me:
Dear Sir,
  The radiation shield (6 rings) is for our 24 HOUR FAN.
24-HOUR
FAN-ASPIRATED
RADIATION SHIELD
Models with 24-hour
fan-aspirated radiation
shields include
additional radiation
shield plates and a
second solar panel,
which powers the
motor-driven fan.
The additional plate is where the Batteries (2, C Cell NiCad), and electronics for recharging the batteries are located, for night time use.

The radiation shield (5 Rings) is our DAYTIME FAN,
Daytime Fan-Aspirated Radiation
Shield Kit
An economical solution for adding the benefits
of fan aspiration by retrofitting your wireless or
cabled Vantage Pro2 or Pro2 Plus. Less costly
than our 24-hour fan-aspirated radiation shield,
but nearly 75% as effective in reducing the effects
of daytime radiation. With no backup battery, the
fan only runs during daylight hours and will cease
running at night when solar radiation effects are
reduced. Retrofit kit for Vantage Pro2 and Vantage
Pro2 Plus includes fan, solar panel, additional
radiation shield plates and hardware.
7747 Daytime Fan-Aspirated Radiation

[plex]

A fresh picture of my unit... You can see the bolts in the bottom, and they are not long enough for one more - not even one cm is visible, and I used the old bolts, that are the longest as well

[George Richardson]

WOW, what a can of worms. Good thing about it is I doubt it makes any difference. It does distress me that Davis would send out an answer from Tech Support that is just plain wrong. The DayFARS is an add-on and I could have assembled it wrong but I bought #2 and #3 used and assembled and they each had 6 plates below the fan housing, but then, 3 of us could have gotten it wrong but, the 24hr FARS is sold assembled from the factory and it comes with 7 rings! As for the screws going thru the base plate, that is actually not a desirable condition because they will likely corrode and you won't be able to remove them. they should terminate within that threaded sleeve, which would happen if you had that extra (top plate modified to remove the Insulating Disk) plate in there (just above that bottom plate).
If you look at http://www.davisnet.com/product_documents/weather/catalog_pages/Weather_Catalog.pdf , page 9, it shows a cut drawing of the 24hr FARS and side, low level picture of a DFARS where you can count the plates.

[plex]

Hello George

I agree the catalog shows 6, but my first pictures is taken from davisnet.com as well - so witch one is right? Maybe it's just the angle of the picture, but anyway the manuel shows 5 in exploded view.

So your setup is like - 2 closed from bottom, one closed with sensor and then 3 open followed by fan section?

I'm asking Davis one more time - with picture.

Maybe I should just add the extra one - to avoid corrosion as you say.

[George Richardson]

OK.

"Maybe it's just the angle of the picture," That's what I think.  "but anyway the manuel shows 5 in exploded view." This is the first time I have seen this diagram and it could indicate Davis has revised their DFARS setup.

"So your setup is like - 2 closed from bottom, one closed with sensor and then 3 open followed by fan section?" YES, that's what I have but it really probably doesn't make any difference.

Good Luck, you will enjoy your toy!

George

[plex]

Thanks George! I'll be back, when Davis answer me again...

[plex]

Guess what... Davis tech support can't help me, with my question - even I send pictures.

Dear Sir
I think you should call your local dealer
For help. They can assist you.

Not quite what I expected from Davis.

Well I'll install the 6th ring - just to projekt the excess bolt.

[PaulMy]

Guess what... Davis tech support can't help me, with my question - even I send pictures.

Dear Sir
I think you should call your local dealer
For help. They can assist you.

Not quite what I expected from Davis.

Also not what I would have expected but possibly they recognized you from outside of North America and may be protecting their world wide dealer network.  A telephone call to Davis (USA) might get you a person who may be helpful but the time difference may complicate that.
 
Paul

[plex]

Maybe it has something to with that Paul - but anyway it's such a simple question?

I've bought the unit outside Denmark, so I won't call our dealer here for advise.

I'll try ask on weather-displays support forum - maybe somebody there can give answers.

I know 5 or 6 rings doesn't make any difference, but it could be interesting to know, how Davis would assemble it. 

[ValentineWeather]

Is everything together correctly? Double checked, did you need to reorient the temperature sensor?

The new kit came with the 3-3 3/4" threaded bolts these go from top base where tipper is mounted into the new threaded spacers.

The old 4" bolts go all the way through all plates starting from new fan plate and thread into the threaded insert bottom plate. There should be plenty of bolt for all plates to fit.

Here is the PDF: http://www.davisnet.com/product_documents/weather/manuals/07395-236_IM_07747.pdf

[plex]

I did need to reorient the sensor, and mount on spacers as described.

Also I used the old bolts from fan plate and down. Yes they can carry 6 but what to believe when exploded view shows 5 and illustrations 6...

[ValentineWeather]

I would use all 6 if it was me. I didn't see anything saying discard one of the plates in the manual.

[plex]

True... One more can't harm

Thanks for helping

[plex]

Just to finish this discussion, I wrote to Davis one more time.

Hello,
         The answer I gave you is the best I can do for now. These are only resellers in the entire country and they are mandated to know how the fan shields are oriented. Apparantly, you did not read the whole thing. Sentence 2 states that you remove the 2 screws holding the insulating disk attached on the underside and DISCARD it. You are given 3 threaded Inserts that mount on the fan plate, and 3, 4” screws that bolt the fan plate to the threaded insert in the bottom 5th plate. Those 4” screws do not bolt in from the black rain base. Your 3 ¼” screws is what you screw into the Black base of the rain collector and into the threaded spacers. Your smallest screws is what you attach from the bottom to hold the inserts in place that the 8-32 X 3 ¼” screws screw into on the fan plate. Point being that the 4” screws are still used but do not screw down from the rain base.

As I understand the last bottom plate is still nr. 5 - but why remove a disc from a plate, that's not even needed, if only 5 should be mounted

[PaulMy]

Glad your persistence got you more information.  The tone leaves a little to be desired but he did attempt/remind to describe what to do.  Hopefully it is helpful.
 
Good luck,
Paul

[Phil23]

Just to update for others, I did mine yesterday.
Kit came from Scaled Instruments & I did end up with 6 plates below the fan.

Plenty of thread on the 4" screws & none showed thru like in the other posted photo.
Only thing that didn't  match was the cable clamp on the Temp/Hum sensor; Mine has the thick clear moulding seen in the pic.

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On a slightly different note, can anyone identify my Temp/Humidity sensor. Unit purchased September 2016.

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Phil.

[CW2274]

On a slightly different note, can anyone identify my Temp/Humidity sensor. Unit purchased September 2016.

Not sure, but I think it's an SHT11. Gently pull the cover off and look. An SHT11 is shaped like an old fashion key hole, the SHT31 is a TINY little square.

[WxLover16]

On a slightly different note, can anyone identify my Temp/Humidity sensor. Unit purchased September 2016.

Not sure, but I think it's an SHT11. Gently pull the cover off and look. An SHT11 is shaped like an old fashion key hole, the SHT31 is a TINY little square.

The 7346.176 on the back gives it away. The SHT31 is 7346.070. He has the SHT11.

[Phil23]

So SHT11 is a fairly old style sensor?

Strange considering the age of the unit & it's build date.

Guessing it may relate to the slower turnover of Australian spec'd units.

Can't easily take the cover off as it's now reassembled.

What info is need to see if it will support a later sensor?

Always doubted it's humidity a bit, only vary rarely see 97% & I think I should have seen that on numerous occasions by now.

Phil.

[CW2274]

So SHT11 is a fairly old style sensor?

What info is need to see if it will support a later sensor?
Phil.

Yes, over 11 years.

None, as it will. If you enjoy accuracy, the 31 is in a different league compared to the 11, especially in the linear response to very low and high humidity.