I currently have a working setup involving a SW4024 inverter. I need more power. I have enough battery/panels, just not enough delivered AC to cover all the peak loads.  so I want to buy a used SW4024, and integrate it into the setup, parallel/series, 120/240, how do wire the ac panel.  single phase/split phase ??  DC disconnect box ??

I am totally off-grid, what do I get for state/fed incentives for upgrades/purchases ??

Comments

First of all, this sounds like a great project.  What you're describing is called "stacking". You'll choose to stack in series for 240/120 voltage - or in parallel for the inverter's native 120VAC with twice the amps. The SW4024 is long-lived and sometimes available on the used market, but because they are so reliable, they don't pop up every day and tend to stay in service until they're killed by lightning or something drastic - shop carefully.  Depending on your choice, you'll also have to find: a Xantrex SW Stacking Cable for SW Inverters and/or Xantrex SWI/PAR Interface for Parallel Stacking. The SW/PAR cable coordinates the sinewave output in parallel operation.  

Here is a link to relevant Xantrex data and Wiring BOS.

And here is a link from the all-knowing Solar Guppy on a couple of things to look out for when planning:

http://www.solar-guppy.com/forum/post1959.html#p1959

Most rebates are for grid tied systems, but take a look here and see if you fit into any of the available programs.

Good luck! This is a good sized system, so make sure you review your lightning protection while the work is underway.

My inverters are SW4024, not the plus model, what are the specific differences ? the manufacturing dates are Q4/1995 and Q1/1999.  where do I buy the parts ?

Sorry about that, the reason I made a more general reference is because the downloads section of the SW Plus product has a lot of useful wiring references that can be used for planning the layout. Specifically, check out the ISC-S cable manual schematics:

http://www.xantrex.com/web/id/831/docserve.aspx

The SW Plus seems to have an onboard transfer switch and possibly higher surge capacity. Here's a description from Wholesale Solar:

"SW Plus 5548 is designed to provide homes with a completely independent power supply, the SW Plus combines an inverter, charger, and dual transfer switch in one package. The SW Plus provides pure sinewave AC power for household appliances and DC power to charge batteries. With a high surge capacity, the SW Plus can start high power loads such as deep well pumps and compressors.

A "Smart Energy Management" system controls utility and/or generator usage. The SW Plus includes forced air cooling, multi-stage charging, control panel and a battery temperature sensor. The Sine Wave Interface (SWI) can be used to stack two SW Plus for double the power output."

The reason I quote Wholesale is because they stocked a large number of the Trace/Xantrex inverters and are a good first choice to search for the cable.

With that said, depending on the choice between parallel or series, you may be able to stack two SWs without the special cable (pages 95 through 97 have very specific information):

http://www.xantrex.com/web/id/940/docserve.aspx

This should be the relevant manual for your inverter. Take a look and then let me know if it isn't and I'll look around for older manuals.

Here is a diagram that might be helpful to solve this issue.

 

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Submitted
13 years 8 months ago
Asked by
rob tribble
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