Author Topic: Fan getting weak  (Read 1115 times)

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Offline CW2274

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Re: Fan getting weak
« Reply #25 on: June 05, 2018, 10:59:30 PM »
I checked battery voltage and it is at 2.9 volts.
But now I assume you checked the ISS batteries?  [Yes, I know what "ass u me" means]
It's DFARS. The battery has nothing to do with the fan, just the transmitter. The solar panel only charges the super-cap and runs the fan when there's ample sunlight.

Offline dalecoy

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Re: Fan getting weak
« Reply #26 on: June 05, 2018, 11:24:52 PM »
I checked battery voltage and it is at 2.9 volts.
But now I assume you checked the ISS batteries?  [Yes, I know what "ass u me" means]
It's DFARS. The battery has nothing to do with the fan, just the transmitter. The solar panel only charges the super-cap and runs the fan when there's ample sunlight.

I understand that.  I was just trying to verify what battery voltage Wxman measured. 

Offline WXman

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Re: Fan getting weak
« Reply #27 on: June 06, 2018, 11:51:41 AM »
I pulled the battery out of the ISS, took it to my workshop, threw the volt meter on it, and got 2.9 volts.  So I assumed it was not the problem and popped it back in.

The fan motor has been changed, as mentioned, so it's not the problem either.

So I guess that leaves two possibilities:  the solar panel or something on the ISS circuit board.

Does anyone know what the output voltage FROM the solar panel on the ISS cover TO the DFARS fan should be?  I'll test mine this afternoon to see what it's putting out.

Also, I would love to buy a supplemental solar panel to wire in also and that way I can face it to the west and have the fan run until the sun actually sets during summer.
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Offline ValentineWeather

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Re: Fan getting weak
« Reply #28 on: June 06, 2018, 12:51:03 PM »
I just checked my dfars solar panel. I'm getting 2.35 volts directly toward the sun. This isn't normal sun angle however. My larger dfars panel comes with 24hr. shield at normal sun angle for cell this time of year facing south is only putting out 1.9 volts.

So around 1.9v would be about what you see at normal sun angle dead of summer. As sun angle is lower more inline with solar cell angle this fall and spring voltage would go up I'm assuming. 

Check voltage output on both cells  dfars panel one goes to fan the other for charging super capacitor.
Randy

Offline dalecoy

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Re: Fan getting weak
« Reply #29 on: June 06, 2018, 01:24:34 PM »
In addition to measuring the voltage of the solar panel with the panel disconnected,

Check the voltage at the fan terminals with the solar panel connected and facing the sun.

Offline ValentineWeather

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Re: Fan getting weak
« Reply #30 on: June 06, 2018, 01:58:33 PM »
I did have one DFARS panel go bad, only happened the one time so its really rare considering. 

Only half the panel went bad the Dfars are split panels. If they are showing voltage regardless of how much depending on sun angle time of day, fan load etc. the panel is good. When a panel goes bad it will show 0 volts.
Randy

Offline dalecoy

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Re: Fan getting weak
« Reply #31 on: June 06, 2018, 02:05:12 PM »
I did have one DFARS panel go bad, only happened the one time so its really rare considering. 

Only half the panel went bad the Dfars are split panels. If they are showing voltage regardless of how much depending on sun angle time of day, fan load etc. the panel is good. When a panel goes bad it will show 0 volts.

There are solar panel failure modes that result in reduced (non-zero) voltage, and also in reduced current capability. 

Offline WXman

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Re: Fan getting weak
« Reply #32 on: June 06, 2018, 05:29:01 PM »
 okay so I got some readings and I learn something new. The upper portion of the solar panel does not have any control over the fan. It's the bottom portion that makes the fan run. I tested the upper portion and got 2.2V facing west toward the sun,  and 2.1V facing south mounted to ISS. But...the bottom portion only outputs 1.83V when facing the sun and drops off to 0.25V when mounted on ISS facing south. At the fan, I get 1.72V with the panel facing the sun. At this point the fan will run. As soon as I turn the solar panel in any direction away from direct sun angle the voltage drops off so fast that the fan won't run.

So, it appears that my solar panel cover is to blame. Does anybody know of a supplemental solar panel that I could tie in along with this one to supply additional voltage? I would like to mount it and face it to the West so that the fan will run for more of the day.
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Offline CW2274

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Re: Fan getting weak
« Reply #33 on: June 06, 2018, 05:42:41 PM »
So, it appears that my solar panel cover is to blame. Does anybody know of a supplemental solar panel that I could tie in along with this one to supply additional voltage? I would like to mount it and face it to the West so that the fan will run for more of the day.
You shouldn't need to supplement anything. I would merely buy another panel cover.
https://www.scaledinstruments.com/shop/davis-instruments/davis-7345-116-pro2-solar-cover-for-daytime-fan-aspirated-radiation-shield-kit/

Offline CW2274

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Re: Fan getting weak
« Reply #34 on: June 06, 2018, 06:11:16 PM »
If you want a more reliable fan that really pulls some serious air (Don't go too high) some here are using AC fans.
This deserves repeating. If you're able, this solves ALL the problems you're experiencing/addressing. Can't recommend this enough.

Offline ValentineWeather

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Re: Fan getting weak
« Reply #35 on: June 06, 2018, 06:50:33 PM »
okay so I got some readings and I learn something new. The upper portion of the solar panel does not have any control over the fan. It's the bottom portion that makes the fan run. I tested the upper portion and got 2.2V facing west toward the sun,  and 2.1V facing south mounted to ISS. But...the bottom portion only outputs 1.83V when facing the sun and drops off to 0.25V when mounted on ISS facing south. At the fan, I get 1.72V with the panel facing the sun. At this point the fan will run. As soon as I turn the solar panel in any direction away from direct sun angle the voltage drops off so fast that the fan won't run.

So, it appears that my solar panel cover is to blame. Does anybody know of a supplemental solar panel that I could tie in along with this one to supply additional voltage? I would like to mount it and face it to the West so that the fan will run for more of the day.

First I would wire the top (good) panel into fan just to make sure... Worst thing to happen is you will drain some of the transmitter battery. These transmitters can go months without any solar. I have one in the garage running just on battery. Plus doesn't take a lot of sun for super cap to charge.  If fan spins normally you will have no doubt. Maybe even try it like that sharing panel for awhile, I'm not convinced you need a full panel just for supercap and transmitter signal.

As far as replacement I would just order a new cover or add the larger solar panel used on 24 hr fars. 

https://www.scaledinstruments.com/shop/davis-instruments/davis-7345-116-pro2-solar-cover-for-daytime-fan-aspirated-radiation-shield-kit/

https://www.scaledinstruments.com/shop/davis-instruments/davis-7345-119-pro2-24hr-spars-solar-panel/
Randy

Offline CW2274

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Re: Fan getting weak
« Reply #36 on: June 06, 2018, 07:00:56 PM »
okay so I got some readings and I learn something new. The upper portion of the solar panel does not have any control over the fan. It's the bottom portion that makes the fan run. I tested the upper portion and got 2.2V facing west toward the sun,  and 2.1V facing south mounted to ISS. But...the bottom portion only outputs 1.83V when facing the sun and drops off to 0.25V when mounted on ISS facing south. At the fan, I get 1.72V with the panel facing the sun. At this point the fan will run. As soon as I turn the solar panel in any direction away from direct sun angle the voltage drops off so fast that the fan won't run.

So, it appears that my solar panel cover is to blame. Does anybody know of a supplemental solar panel that I could tie in along with this one to supply additional voltage? I would like to mount it and face it to the West so that the fan will run for more of the day.
or add the larger solar panel used on 24 hr fars. 
https://www.scaledinstruments.com/shop/davis-instruments/davis-7345-119-pro2-24hr-spars-solar-panel/
If you don't want/can't do a/c, I'll give you this, used of course, but still should work just fine. It's merely siting in my spare parts bin collecting dust, as I'll probably never use it again.

Offline ValentineWeather

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Re: Fan getting weak
« Reply #37 on: June 06, 2018, 07:19:21 PM »
Good deal..    [ You are not allowed to view attachments ]
Randy

Offline WXman

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Re: Fan getting weak
« Reply #38 on: June 07, 2018, 07:04:39 AM »
okay so I got some readings and I learn something new. The upper portion of the solar panel does not have any control over the fan. It's the bottom portion that makes the fan run. I tested the upper portion and got 2.2V facing west toward the sun,  and 2.1V facing south mounted to ISS. But...the bottom portion only outputs 1.83V when facing the sun and drops off to 0.25V when mounted on ISS facing south. At the fan, I get 1.72V with the panel facing the sun. At this point the fan will run. As soon as I turn the solar panel in any direction away from direct sun angle the voltage drops off so fast that the fan won't run.

So, it appears that my solar panel cover is to blame. Does anybody know of a supplemental solar panel that I could tie in along with this one to supply additional voltage? I would like to mount it and face it to the West so that the fan will run for more of the day.
or add the larger solar panel used on 24 hr fars. 
https://www.scaledinstruments.com/shop/davis-instruments/davis-7345-119-pro2-24hr-spars-solar-panel/
If you don't want/can't do a/c, I'll give you this, used of course, but still should work just fine. It's merely siting in my spare parts bin collecting dust, as I'll probably never use it again.

You have a spare solar cover you'll never use again?  That would be great.  But it looks like they are relatively inexpensive at scaled instruments so I don't mind buying one if you think you may ever have another use for yours.

I can't do AC because it's just not feasible in the location where my station is out in the field.

Reason I was considering a second panel to face west is that I figured it would help keep the fan going longer as the sun is setting and the air is still hot and humid for a while.  But I guess I'll try a new cover first and see how it works.

Thanks for all the help.
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Offline CW2274

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Re: Fan getting weak
« Reply #39 on: June 07, 2018, 03:56:15 PM »
okay so I got some readings and I learn something new. The upper portion of the solar panel does not have any control over the fan. It's the bottom portion that makes the fan run. I tested the upper portion and got 2.2V facing west toward the sun,  and 2.1V facing south mounted to ISS. But...the bottom portion only outputs 1.83V when facing the sun and drops off to 0.25V when mounted on ISS facing south. At the fan, I get 1.72V with the panel facing the sun. At this point the fan will run. As soon as I turn the solar panel in any direction away from direct sun angle the voltage drops off so fast that the fan won't run.

So, it appears that my solar panel cover is to blame. Does anybody know of a supplemental solar panel that I could tie in along with this one to supply additional voltage? I would like to mount it and face it to the West so that the fan will run for more of the day.
or add the larger solar panel used on 24 hr fars. 
https://www.scaledinstruments.com/shop/davis-instruments/davis-7345-119-pro2-24hr-spars-solar-panel/
If you don't want/can't do a/c, I'll give you this, used of course, but still should work just fine. It's merely siting in my spare parts bin collecting dust, as I'll probably never use it again.

You have a spare solar cover you'll never use again? 
No sir, not a cover, this is the panel that charges the fan's batteries and runs the fan itself on the 24hr FARS. I no longer use it.
https://www.scaledinstruments.com/shop/davis-instruments/davis-7345-119-pro2-24hr-spars-solar-panel/

If you're getting a new solar cover for the DFARS, I'd see if that solves your issues before messing with the 24hr panel. If you decide you still want it, it yours.

Offline WXman

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Re: Fan getting weak
« Reply #40 on: June 08, 2018, 01:57:12 PM »
Thanks everyone for the help.  I'm going to order a new cover pretty soon and hopefully that'll fix the issues.
B.S. in Meteorology/Climatology

38.01977N, 84.83486W
Davis Vantage Pro 2 wireless station
Hoping to get it online soon!