[RE-wrenches] Fw: Xantrex C-40 Drifting

[Drake]

The modules are Sunwise 22 V, 40 W modules.  The model number of the 
modules is SW-S40P SWT.  The are wired in series for a 24 V nominal 
system.  That would be an mppt voltage of 44 V on a system that 
directs batteries to absorb at 29.4 volts. I'm not sure what the NOCT 
voltage would be, but it would seem like it would be an ok fit?

I think you are on the right track with the MPPT charging graph. The 
CC likely allows pulses of full charge to hit when the batteries are 
at their maximum set point voltage.

Would a very short pulse of high voltage be a problem of a VRLA 
battery? Could any significant gassing take place?

Thanks,

Drake



At 06:04 PM 5/19/2015, you wrote:
>Hi:
>
>We haven't changed anything the in C40.  The essence of my idea was 
>that perhaps the "trouble" systems are the ones which have much 
>higher module Voc versus battery Vfloat.
>
>JARMO
>_____________________________________________________________________________________ 
>
>
>Jarmo Venalainen  |   Schneider Electric   |  Xantrex 
>Brand  |   CANADA  |   Sales Application Engineer
>Phone: +604-422-2528  |   Tech Support: 800-670-0707  |   Mobile: 
>+604-505-0291
>Email: 
><mailto:jarmo.venalainen at schneider-electric.com>jarmo.venalainen at schneider-electric.com 
>|   Site: www.Xantrex.com  |   Address: 3700 Gilmore Way, Burnaby, BC V5G4M1
><http://www.xantrex.com/>
>[]
>  <https://www.facebook.com/Xantrex>
>[]
> <https://twitter.com/Xantrex>
>[]
> <https://twitter.com/Xantrex>
>[]
>
>
>
>*** Please consider the environment before printing this e-mail
>
>
>
>From: Ray Walters <ray at solarray.com>
>To: RE-wrenches <re-wrenches at lists.re-wrenches.org>,
>Date: 05/19/2015 11:00 AM
>Subject: Re: [RE-wrenches] Fw:  Xantrex C-40 Drifting
>Sent by: "RE-wrenches" <re-wrenches-bounces at lists.re-wrenches.org>
>
>
>
>
>Hi Jarmo;
>
>Early solar systems actually tried to use the principle of matching 
>array Vmpp to battery voltage  in lieu of charge controllers.  The 
>biggest issue is that when it is is hot the module voltage can drop 
>below the battery voltage needed, and when its cold the voltage will 
>still be too high.   Batteries were either over charged or never 
>reached full charge depending on the conditions.
>I've used the C40 successfully for decades, so I'm wondering if the 
>circuitry changed recently, or if different tolerance components 
>were substituted that may be causing the drift?
>
>Thanks,
>R.Ray Walters
>CTO, Solarray, Inc
>Nabcep Certified PV Installer,
>Licensed Master Electrician
>Solar Design Engineer
>303 505-8760
>On 5/19/2015 10:31 AM, 
><mailto:Jarmo.Venalainen at schneider-electric.com>Jarmo.Venalainen at schneider-electric.com 
>wrote:
>Hi:
>
>I didn't know that there were systems out there where a PWM charge 
>controller such as the C-40 was producing an unhealthy, high battery 
>voltage.  Since there are, I may have a possible explanation.
>
>The C-series and other PWM type charge controllers operate by PWM 
>whereby they very very quickly connect/disconnect the solar module 
>to the battery bank.  The amount of time which the module is 
>connected to the array is the PWM on-period.  These controllers do 
>not have the ability to "smooth out" the output voltage.  All they 
>can do is apply the full module voltage OR not a
>
>
>______________________________________________________________________
>This email has been scanned by the Symantec Email Security.cloud service.
>_____________________________________________________________________________________________________________________
>List sponsored by Redwood Alliance
>
>List Address: RE-wrenches at lists.re-wrenches.org
>
>Change listserver email address & settings:
><http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
>List-Archive: 
><http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html>http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
>List rules & etiquette:
><www.re-wrenches.org/etiquette.htm>www.re-wrenches.org/etiquette.htm
>
>Check out or update participant bios:
><www.members.re-wrenches.htm>www.members.re-wrenches.org
>
>
>
>
>
>_______________________________________________
>List sponsored by Redwood Alliance
>
>List Address: RE-wrenches at lists.re-wrenches.org
>
>Change listserver email address & settings:
>http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
>List-Archive: 
>http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
>List rules & etiquette:
>www.re-wrenches.org/etiquette.htm
>
>Check out or update participant bios:
>www.members.re-wrenches.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20150520/ffa2080b/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 8b64bdb.gif
Type: image/gif
Size: 4274 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20150520/ffa2080b/attachment-0020.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 8b64c1a.gif
Type: image/gif
Size: 1869 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20150520/ffa2080b/attachment-0021.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 8b64c29.gif
Type: image/gif
Size: 1897 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20150520/ffa2080b/attachment-0022.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 8b64c39.gif
Type: image/gif
Size: 2041 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20150520/ffa2080b/attachment-0023.gif>