Arctic Alpine 11 plus discrepancy.

I got my LEDs mounted to my heatsinks, without breaking a bit or tap I might add. I always like to test things so I Hooked the fans up in parallel and attached them to my adjustable power supply to see how many amps they would draw, and was a little confused. The box says at 12v the fan requires 0.24A however all three of them consumed 0.57A it doesn't add up. I am familiar how voltage and amps work in parallel and series circuits. Anybody care to offer an explanation?

I would be concerned more with it drawing more...not less. Load changes all parameters.

Oh trust me I'm not worried, it's great that it draws less. In this case however isn't the load already calculated, and how would the load change. Maybe as the fan got dirty and somehow created some resistance, but that could only be nominal.

I would think the .24A is a maximum. Usually at start up. It would happen so fast you probably couldn't even see it on your meter.

I thought the same thing at startup there an initial spike in draw. However that's a good point that it would be a maximum and not a constant. It's probably more relevant for a power supply in a computer anyway.

In that picture is that a meter or a power supply that shows what it's putting out and you can control the voltage?

That is a adjustable power supply.

Do you have a link for it?

Load changes because of many parameters: heat, components, circuitry.

Efficiency is going to skew that #.

95'ZR1 said:

Do you have a link for it?

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Not at the moment, let me see what I can come up with.

I just re built one of my lights that uses artic coolers. I never tested the fan before so don't have anything but observation to go off here but...
The fans were quiet and always seems slow to me, but my case and heatsink temps were dandy, so never questioned it...also was my first time with artics. I just yesterday rebuilt the light...re-did some soldering of a loose connection on one fan...and now I have much more air movement on all my fans.
I think that when stripping the artic wires it is easy to take a few strands off...since there isn't many strands in those little wres to start, there isn't many to spare. And that plus the sketchy soldering made a shitty circuit and I wasn't getting full power.

Sounds like you have a different problem than I did...but is worth double checking all the connections anyways.

Abiqua said:

Load changes because of many parameters: heat, components, circuitry.

Efficiency is going to skew that #.

Click to expand...

You bring up very valid points. But isn't the fan the only component? And the circuitry I assume has already been taken into account by the manufacturer, weather proprietary or not. So I could see as the temp in my grow area increases that would increase the load, a bit.

Greengenes707 said:

I just re built one of my lights that uses artic coolers. I never tested the fan before so don't have anything but observation to go off here but...
The fans were quiet and always seems slow to me, but my case and heatsink temps were dandy, so never questioned it...also was my first time with artics. I just yesterday rebuilt the light...re-did some soldering of a loose connection on one fan...and now I have much more air movement on all my fans.
I think that when stripping the artic wires it is easy to take a few strands off...since there isn't many strands in those little wres to start, there isn't many to spare. And that plus the sketchy soldering made a shitty circuit and I wasn't getting full power.

Sounds like you have a different problem than I did...but is worth double checking all the connections anyways.

Click to expand...

Your dam right there aren't to many strands! I had to cut one of them twice and rest strip the insulation so that all the strands were intact. My fan speeds are all about the same I checked with a rpm meter that I have. My temps are perfect as well. I guess what I a missing is that a minimum amp draw at this point is unknown, and most likely is what I am operating at.

NorthernHize said:

You bring up very valid points. But isn't the fan the only component? And the circuitry I assume has already been taken into account by the manufacturer, weather proprietary or not. So I could see as the temp in my grow area increases that would increase the load, a bit.

Click to expand...

Yes, but the power supplies will vary...I bet if you could calculate efficiency of the circuit and subtract the v drop, and it probably would be inline with specs....

Agan, this all seems normal, what isn't normal is when your 12v fan is drawing 15v's in a unregulated power supply.....

I hear ya, thanks!

Yep I measured .17A @ 12V although it varies from fan to fan. Updated technical data on their website says:
.16A @12V (1.92W)
.4 sone
2000rpm
74cfm
6 Year Warranty

SupraSPL said:

Yep I measured .17A @ 12V although it varies from fan to fan.

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Thank you! At least someone can backup my findings.

I have a note pad I write stuff down in and I just saw under my notes on the alpines I have .18a written down. Can't find a link in my files to where it would be from, but ill keep looking. I'm out of town right now otherwise I would just go test them.

Greengenes707 said:

I have a note pad I write stuff down in and I just saw under my notes on the alpines I have .18a written down. Can't find a link in my files to where it would be from, but ill keep looking. I'm out of town right now otherwise I would just go test them.

Click to expand...

.18 amps is right there with what myself and Supra tested ours at. Like I said I'm not paranoid or worried but at the figures I came up with it was like only have 2 fans running at the suggested amp draw.

95'ZR1 said:

Do you have a link for it?

Click to expand...

I dint check for a link. However it is a Lascar PSU 130. I think it came from Digikey.