[RE-wrenches] Xantrex C-40 Drifting

[jay peltz]

HI Drake,

Iv'e never seen this happen.
But have you considered a small morningstar or similar?

A question, you list 29.4v, that seems high?

jay



On Thu, May 14, 2015 at 5:12 PM, Drake <drake.chamberlin at redwoodalliance.org
> wrote:

>  I have a Xantrex C-40 that won't keep its settings. It is important that
> it does because it is for a maintainer array (80 W) on an AGM battery bank,
> on an AC coupled backup system. Not only could high voltage damage the
> batteries, but when the voltage goes over 30 Volts, the AUX relay opens and
> the grid tie inverter is isolated from the grid.
>
> After numerous sessions of reprogramming, Xantrex tech support sent me a
> new unit. The problem persisted as before. A new temperature sensor helped,
> but the settings still drift. It seems that rebooting the charge controller
> helps for a day or so, but then it drifts again.
>
> The potentiometer settings are way below the calculated setting for 29.4
> V, but it still peaks in the high 30s. I check the temperature compensated
> voltages on the Outback Mate, and the temp compensated voltage runs high.
>
> In a related side issue, the AUX relay of the FX inverters is not based on
> temperature compensated voltage, which makes setting AC coupling charge set
> points more problematic.
>
> Has anyone experienced a C-40 CC that drifts in its settings. What would
> be a good (inexpensive) charge controller to accurately control 80 W of PV?
>
> Thanks,
>
> Drake
>
>


-- 
Jay Peltz
Peltz Power
jay.peltz at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20150515/1bf61e4b/attachment-0002.html>