[RE-wrenches] AC Coupling

[wirewiz at gmail.com]

Yes, there should be an uptick in at least inquiries about solar backup here in the NE.

I went to a site in CT where I was called in to see why the customer was upset about why her backup batteries went dead when she was told the solar would stay on line and charge them during what is now week long outages in lots of CT, including my daughter. Luckily for us  our power stayed on and we've had our granddaughter all week. We're not giving her back or maybe not.

Anyway, I found that one of the installers involved (there are two, one did the grid tie and one did the backup and are now pointing fingers at each other) thought they could install charge controllers and during an outage then divert the grid tie solar string voltage to the batteries through these controllers. I was told they were Outback MX or FM60's but I found two totally blue boxes, no labeling whatsoever and have no idea who the manufacturer is??. Realizing, I guess, that the string voltage was way too high, the connections were never made but the equipment was left there on the wall as a disguise (maybe) hoping we would never have a long outage like this.

It remains to be seen if the existing Xantrex SW5548's can be AC coupled to the Sunpower X inverter. Me, I'm heading for the hills on this one.

I also have an ethics issue question here. If you were asked by the installer to check the system and saw what I saw would you tell the furious customer who wanted answers or leave it up to the installer(s) to do the right thing even though it's clear to me that they already deceived her. Why neither installer, instead of me, came to check the system or did not even want to be present when I was there is strange to me. Maybe I should not have gotten involved.  

Anyone, ever see or hear of plain boxes with no labeling being installed as controllers. 

Thank you.

Larry Liesner
Wirewiz
31 Lincoln St
Westport, CT 06880
Phone: 203-644-2404
wirewiz at gmail.com
www.wire-wiz.com




On Sep 2, 2011, at 11:51 AM, Larry Brown wrote:

> Wrenches,
> 
> After Hurricane Irene left a lot of people without power here in the Northeast, customers who have grid-tied systems are asking about some battery backup to power some essential loads.
> 
> We have used Sunny Islands but they require either 2 Sunny Islands or a step up transformer to get 240 volts for the well pump.  Schneider Electric  (Xantrex XW) inverters look like they would work  for this application and do 120/240 volt output as well and we have used these in off grid applications but not as AC coupled.  I have considered Magnum because they also do 120/240 volts but they need battery diversion to ensure the batteries are not over charged.
> 
> None of these systems are going to be rewired as a DC system so I am looking for any feed back on what others are using to AC couple to existing grid-tied systems to provide some battery backup.
> 
> Thanks
> Larry
> 
> Larry Brown
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