XW4548 dropping out of sell mode

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   I've been working with Xantrex tech support trying to resolve a problem where the system seems to be dropping out of sell mode too frequently.  Does anyone have experience with parameter changes possibly causing confusion in the inverter and a "reboot" method via a forced bulk charge?  Also, I can't find any technical document describing the basic inverter sell mode algorithm interacting with the charge controller and battery bank...does anyone have any experience or literature on this subject?  Thanks for any help.

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mo Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 31 May 2009 Online Status: Offline Posts: 13	Quote Reply Topic: XW4548 dropping out of sell mode Posted: 14 July 2009 at 11:43pm
	I've been working with Xantrex tech support trying to resolve a problem where the system seems to be dropping out of sell mode too frequently. Does anyone have experience with parameter changes possibly causing confusion in the inverter and a "reboot" method via a forced bulk charge? Also, I can't find any technical document describing the basic inverter sell mode algorithm interacting with the charge controller and battery bank...does anyone have any experience or literature on this subject? Thanks for any help.

dlenox Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Member Joined: 22 July 2008 Location: wv, usa Online Status: Offline Posts: 49	Quote Reply Posted: 21 July 2009 at 12:53pm
	mo, you did not state what the dc input source was. I do know that the XW series inverters have a 20 second delay once the support volts is obtained before it will go into sell mode. meaning that the battery volts have to be >= sell volts continously for this period, if the volts drop the time cycle starts over again. in addition once in sell mode if the battery volts go below the sell volts for the same 20 second period it will stop selling, and starting up the cycle all over again. I discovered this delay time a little over 6 months ago and reported it to Xantrex. I thought that they were coming out with a firmware modification to change this but am not sure if they have released it yet. This is extremely problematic for wind turbines as they can raise the battery volts quickly. And on semi-windy days my PowerDashboard monitoring software has seen the inverter allow the battery volts to go to 64+ volts (in 48v system) while waiting for this time period... hope this helps, Dan Lenox

mo Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 31 May 2009 Online Status: Offline Posts: 13	Quote Reply Posted: 22 July 2009 at 12:18am
	Dan, I have a 396Ah 48VDC bank of AGM batteries for the DC input. The PV is a 4.2kW with two XW-MPPT60-150 charge controllers feeding the XW system. With the inverter firmware of 1.04 (latest that I can tell from the website), I didn't know what the timeout was before dropping out of sell mode. Thanks for the info. Have you seen, or felt that the inverter was selling too much and dropping the battery voltage? Or in your experience, it was the PV/charge controller not harvesting enough?

Solar Guppy Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Senior Member Joined: 27 May 2004 Location: United States Online Status: Offline Posts: 145	Quote Reply Posted: 22 July 2009 at 5:18am
	Downgrade to 1.03 ... 1.04 has serious issues with selling, dropping offline in irradiance changes is what I observed on my unit. Also, set your sell voltage to 52V ... this with 1.03 should work fine

mo Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 31 May 2009 Online Status: Offline Posts: 13	Quote Reply Posted: 29 July 2009 at 11:46pm
	To make a long story short, the XW4548 did not have a released 1.03 version, but there was a 1.0 version. After downloading the 1.0 firmware version to the inverter/charger, immediately the dropping out of sell mode stopped. I now am working with Charles and engineering to provide a bug fix to 1.04 for the XW4548...supposedly around end-August timeframe for completion. The old firmware version prevents daily battery charging as the 52V grid support voltage prevents bulk/abs charging at 57.2V, so I don't want to run too long this way. Thanks for the help as your hint of downgrading the firmware provided a temporary workaround. Now my customer is much happier for the time being monitoring what he buys/sells to the utility.

Solar Guppy Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Senior Member Joined: 27 May 2004 Location: United States Online Status: Offline Posts: 145	Quote Reply Posted: 30 July 2009 at 1:56pm
	There is no point of daily grid to battery charging if your doing Sell mode ... Batterys will be fine, I've run this way 2 years

mo Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 31 May 2009 Online Status: Offline Posts: 13	Quote Reply Posted: 07 October 2009 at 4:55pm
	Working with Xantrex, new beta 1.05 firmware was installed on the XW4548 and XW60. Now system is performing very well selling in cloudy conditions. The final new release version should be out soon once some bugs are fixed that were identified during my testing.

dlenox Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Member Joined: 22 July 2008 Location: wv, usa Online Status: Offline Posts: 49	Quote Reply Posted: 08 October 2009 at 5:54am
	SG, So on the XW inverters to stop occasional battery charging, do you simply turn the Charging setting to off? Dan Lenox

mo Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 31 May 2009 Online Status: Offline Posts: 13	Quote Reply Posted: 08 October 2009 at 9:07pm
	I also enabled load shaving for my customer and set the charge block feature to only allow late afternoon inverter charging (if needed) daily for 1 hour. This will allow PV charging as priority and on extremely cloudy days, will the inverter be allowed to charge the batteries. Voltage thresholds make everything easy to setup. So far the XW4548 with the new beta 1.05 firmware is working very well.