fan temp settings

[kitestrings]

Hi folks,

A question:

Is it possible to change the fan temp settings on the Classic?  We have two Classic  250's (SN415, 418 Rev: 1401 06/08/13) operating on a wind turbine.  From observation, the fan appears to actuate based on FET temp: ON 48C, OFF 46C.  This may be fine, but because one controller normally takes most of the load up to its current limit, this unit cycles much more.  In higher wind conditions the right side of the CC gets notably hotter.  I assume this is where the FETs are.  They are located in a mudroom living space that is usually a tad cooler than the rest of the house.

As I understand it heat is the enemy long-term when it comes to electronics...and wind output can fluctuate a lot more/more rapidly than PV.  If the fan ran more and/or longer this might help was my thought.

~ks

[tecnodave]

Kitestrings,

The temp of the fans is set in software somewhere, it has been changed in the past. I do not know if it is user settable.  You are correct in that the fet's are on the right side, you can see them in a row on the right edge of the main board when the cover is removed.  On balancing power between the two classics,  I have two classics on solar and I achieve load balancing between then by adjusting the battery voltage value in "tweaks" to achieve equal loading on the classics.

David

[kitestrings]

Thanks for the response.  I think they may have actually moved it the other way (higher set points, and/or increased the hysteresis) to reduce run-time/noise.  I'm not positive, but it seems I read something to that effect.

BTW, that should have been:

From observation, the fan appears to actuate based on FET temp: ON 48C, OFF 45C.

It seems to work fine, I just wondered if it was buried in a menu that I'd missed.

On balancing power between the two classics,..

Unfortunately, with the wind track/mode this is not really an option.  They had talked about a firmware that would share the load equally, but with PV so much more common, I can see where this may have not been pursued.  The prevalent mode seems to be to have one load to a preset current limit, at which point the voltage rises a bit sharper.  This becomes the first step of the second controller which starts its power curve at that same voltage.

Ours:
http://www.fieldlines.com/index.php/topic,149124.0.html?PHPSESSID=348ea210a95b72ecc07fde97e894788d

It's been working great, but it surely works the first unit harder (from a load and thermal perspective).

Oh, Here's Ryan's diagram -
http://www.midnitesolar.com/pdfs/Ryans_stacking.pdf

~ks

[ClassicCrazy]

I think I remember reading that the fan voltage was lowered in the newest firmware update, but it would only work for newer Classic boards and not the older ones.

Larry