To add; I am a firm believer that every few years I will send OB CC/Mates in for firmware up date. I will repole an off grid system at least twice a year. Temp sensor is imperative! and if the site is not maned do not set auto eq. On Nov 18, 2014, at 1:40 PM, Allan Sindelar wrote:
> Drake, > I'll add just a bit to Jarmo's excellent reply: > You mentioned that you were unsure if the MX60 was set to auto-EQ. This could > be a source of trouble. The MX60 had the unfortunate characteristic whereby > if set to auto-EQ, it would continue to try to complete an EQ indefinitely > once triggered. As such, if the array was not sufficient to hold the > batteries above the EQ voltage for the set duration, or as the batteries aged > and their internal resistance increased such that the EQ voltage couldn't be > maintained, the controller would never complete and exit EQ mode. 31V, while > conservative, is high enough to cause this. > > If that is what occurred here, then disabling automatic EQ and reducing the > EQ voltage below gassing threshold should prevent recurrence. > Allan > > Allan Sindelar > [email protected] > NABCEP Certified PV Installation Professional > NABCEP Certified Technical Sales Professional > New Mexico EE98J Journeyman Electrician > Founder (Retired), Positive Energy, Inc. > 505 780-2738 cell > > > On 11/18/2014 11:03 AM, [email protected] wrote: >> Hi: >> >> This may not be the problem, but I wanted to bring it up as I have heard of >> a few cases of battery boiling issues with various charge controllers and >> want to suggest a possible cause. >> >> I'll do this point form. It's easier to describe it that way: >> >> 1. Solar charge controllers are programmed to go to bulk charge in the >> morning. >> 2. The intensity of the sunlight starts off low in the morning and depending >> on the weather during the day, the intensity can reach any level between >> virtually 0% and 100%. >> 3. The exit criteria for bulk is that the battery voltage reaches the >> Vbulk/abs volts setting or a bulk/abs timer times out. >> 4. If the sunlight conditions are just right to keep the charging voltage >> just below the Vbulk/abs setpoint, the exit from bulk/abs will be the timer. >> 5. Bulk/Abs timers are usually set for rather a long time, many hours is not >> uncommon. >> 6. Given the above, it is possible that the battery stays at gassing >> voltages for many hours every day at certain times of the year when the >> sunlight intensity is just right to support that. >> 7. As a consequence the boiling problem will show up only at particular >> sites, particular battery/charge controller sizes and particular times of >> year. >> >> Again, I am not suggesting that this is necessarily the cause of battery >> "boiling" in systems with solar charge controllers, but it could be a >> reason. >> >> 2nd ps. All manufacturers do precise battery voltage/current measurements >> on the bench with a wide variety of conditions, but we will never be able to >> simulate the 1000's of conditions that happen on the 1000's of installs out >> there. With that in mind, on-site battery voltage/current data logging is a >> very powerful tool when investigating these kinds of issues. >> >> JARMO >> _____________________________________________________________________________________ >> >> >> Jarmo Venalainen | Schneider Electric | Solar Business | CANADA | >> Training & Development Specialist - Senior >> Phone: +604-422-2528 | Fax: +604-420-1591 | Mobile: +604-505-0291 >> Email: [email protected] | Site: www.SEsolar.com | >> Address: 3700 Gilmore Way, Burnaby, BC V5G4M1 >> >> <Mail Attachment.jpeg> >> *** Please consider the environment before printing this e-mail >> >> >> >> From: Drake <[email protected]> >> To: RE-wrenches <[email protected]>, >> Date: 11/18/2014 09:15 AM >> Subject: [RE-wrenches] Suspect MX 60 >> Sent by: "RE-wrenches" <[email protected]> >> >> >> >> Hello Wrenches, >> >> An MX 60 boiled a 24 volt bank of 4 Trojan L-16 batteries last summer. The >> batteries all checked out to be in good shape. It is not totally clear that >> the CC was not set to auto equalize, but the EQ voltage was only set at 31.0 >> V. >> >> The battery bank has been replaced by 8 Full River L-16 AGM batteries. The >> parameters have all been reset for AGM with EQ disabled. The homeowners are >> concerned that the charge control may not work, and damage their new battery >> bank. >> >> If there is a problem with the CC, it is very intermittent. Has anyone ever >> seen an intermittent MX 60? >> >> Outback tech support says if we send it in they will update the firmware for >> $90, and do a 24 hour bench test. It appears that the firmware update will >> not do anything useful for this off grid system. There are no new boards >> available for this unit. I'm not sure if the bench test will show up an >> intermittent problem. >> >> Has anyone had this situation before? Would it be better to: >> Replace the CC >> Send the CC to Outback >> Do nothing >> Thank you, >> >> Drake >> >> Drake Chamberlin >> Athens Electric LLC >> OH License 44810 >> CO License 3773 >> NABCEP Certified Solar PV >> 740-448-7328 >> http://athens-electric.com/ >> >> >> >> ______________________________________________________________________ >> This email has been scanned by the Symantec Email Security.cloud service. >> _____________________________________________________________________________________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> >> >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > [email protected] www.SWNL.net > Solarwinds Northernlights > Serving Mid Coast Maine & Northern California > 207-832-7574 Cl. 610-517-8401 > > Blair "TUMP" May > ******** MAINE'S CHARTER ******** > NABCEP "Certified PV Installer" > > ******** MAINE'S CHARTER ******** > Trace Xantrex "Certified" Dealer / Installer" >
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