[RE-wrenches] Convert Grid Tie SW4048 to Backup System; Add New Inverter, AC Coupled

jay peltz jay at asis.com
Thu Nov 17 16:51:16 PST 2011


HI Richard,

I'll chime in, although you won't like it.

Dump the system and start over with a new battery less system and a genny as back up.

Told you, you wouldn't like it.

The SW parts are basically gone and it was a terrible  grid tied inverter anyway.
The modules are usable but why at $1.5 watt keep them?
Client doesn't want MX, so that means no batteries.

You'll need a genny as back up anyway for long power outages during storms, so get a natural gas/propane unit as back up instead of batteries.

OK you asked,

jay

peltz power
On Nov 17, 2011, at 4:03 PM, Richard L Ratico wrote:

> Hi Wrenches,
> 
> This is a repost. No replies the first time, so I'm trying one last time.
> 
> I may be "adopting" an eleven year old, Y2K, grid tie with battery back-up
> system. It consists of 12 - Astro-Power 120 modules, installed in 2000, 12 -
> Evergreen  EC-110 modules installed in 2004, only one MX60, which controls BOTH
> sub-arrays, one SW4048 in SELL mode through a dedicated load sub-panel.
> Existing, seven year old battery is shot (8-Trojan L-16). Initial bank of
> unknown batteries was replaced after only four years.
> 
> Recent long, nearby, utility outages have the client requesting a proposal to
> include a new back-up generator and to restore the system selling to the grid.
> Client may decide go straight grid tie to eliminate the batteries. They have
> found the maintenance to be a hassle.
> 
> My thoughts so far: 
> 
> 1)To take advantage of most of the existing hardware, I wonder if it makes sense
> to try to improve the system efficiency by relegating the SW to a manual back-up
> mode only, where, say, by means of a timer controlling grid availability through
> AC1, it would only charge a smaller battery bank once a week. The battery bank
> would be small,
> a single string of either, sealed gel units or T-105s with the new Trojan
> watering system. 
> 2) Provide new grid-tie inverter/s (appropriate string type or Enphase 190s) to
> handle the net metering. 
> 3) Provide a way to AC couple the new inverter/s to the SW in the event of an
> outage.
> 4) Provide a new Honda 3000 inverter type generator connected to AC2 in the SW.
> 5)Provide a way to lockout the grid tie inverter/s when the generator is
> operating.
> 
> Any thoughts or suggestions would be greatly appreciated.
> 
> Thanks in advance, 
> 
> Dick Ratico
> Solarwind Electric
> Bradford, VT
> _______________________________________________
> Li




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