Sunny Boy with tracker [RE-wrenches]

[Allan Sindelar]

Ray, Jay, and Wrenches,
I had posted this request on the 12th:
"We're doing our first Sunny Boy installation. (We have no state incentives,
so batteryless intertie takes a certain type of committed, green pioneer.) I
have planned ten Solarex SX120s @ 24V each on a Wattsun DA model 200
tracker; a second tracker pole set for a future doubling of the array; and a
Sunny Boy 2500. I need some advice on methods that have worked and pass
code."
I asked about ways to power the tracker. Ray had responded:
> How come you can't run the tracker array direct? You'd only lose the
> nightly reset to the east and the tracker would run slower  when off
focus.
> I don't think its worth all the AC hassles you are considering.
Ron at Array Tech had nixed that idea (tapping off of a portion of the
single high-voltage series string to run the tracker) as not workable with
the Sunny Boy.
Wiles also nixed it as too dangerous in a fault condition: "I wouldn't tap
the main array-too risky if something opens up, you could get 400+ VDC on
the tracker circuits. A separate PV module(s) would work OK, but might cost
more.  You probably need 2.5 amps at 24 volts = 60 watts. Batteries are not
needed if you are willing to wait for full sun on the module before a
morning turn to the East."

> If you have to have that first morning's light, perhaps a tiny sealed
> battery pack at the pole just for the tracker? I've used Wattsun for years
> and it  takes less than 0.3 A-Hr / day @ 24 VDC nom. I'd try a 5 A-Hr
> battery w/ a 5A controller that was a parasite off of a single SX-120
> module... or even put up a pair of 1.5 watt modules ($35/ea.-Schott) in
> series.... they're 4.75" x9" and would fit almost anywhere. I'd stick to
> DC. I think if you keep it isolated from all of the other wiring and call
> the the whole mini power system: "tracking equipment", you'll avoid any UL
> listing related inspection hassles. The Wattsun tracker isn't UL either is
it?
Ron recommended against this as prone to problems and not reliable.
So we're using AC-DC supply at this point.

Thanks for the help.
Allan at Pos E

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://www.topica.com/lists/RE-wrenches/

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

Check out participant bios: www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com

==^================================================================
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9
Or send an email to: RE-wrenches-unsubscribe at topica.com

T O P I C A -- Register now to manage your mail!
http://www.topica.com/partner/tag02/register
==^================================================================