24 volt wind into 12 volt bank??? [RE-wrenches]

[Solar Ray]

Hey I love the Bergey XL.1, but yea it puts out way more power than rated. I
have measured sustained 62 amp output at 27 volts, and I had trouble too.
I was so used to the wimpy output of the Air 403s, I never dreamed I would
have trouble with a wind unit putting out MORE than its rated output. I
can't advise you on the converter setup other than I too have had poor
results with split banks using a Vanner equalizer and I too have had my
share of DCDC transformer failures. I would probably go step down with a
combination of converters that could handle at least 80 amps. I wouldn't be
surprised if the Bergey could surge (10ms) that high especially at lower
battery voltages.

Ray
solarray.com


----- Original Message ----- 
From: "RE wrenches" <Geoff at Third-Sun.Com>
To: <RE-wrenches at topica.com>
Sent: Friday, December 05, 2003 8:35 AM
Subject: 24 volt wind into 12 volt bank??? [RE-wrenches]


> OK - here is a good problem to sink your teeth into, and it involves no
> trigonometry!
>
> A year ago I was asked to install a wind genny into a poorly designed and
> poorly functioning system. (Graham has also helped this customer with
> advice). Off grid, one 240 load (well pump) someone sold her a stacked
power
> panel and set up a 12 volt system!  undersized solar, big line losses, no
> design work, no breakers, no metering, no load analysis, 16 T-105 batts...
> I should have advised her to start over...
>
> She has a huge diesel genny on auto that starts about 6 times a day
> (typically when well pump surge brings down voltage) and slams 200 amps
into
> that small bank!  (oh - terrible corrosion at bank interconnects and it
> wasn't cabled from the corners...).  So... I have corrected all these
> problems (still need to turn down the charge amperage though, the voltage
> climbs quickly and the thing runs for 1/2 hour max).
>
> So... the wind...  In hindsight, perhaps I should have gone for a 12V
unit,
> but I like the Bergey XL-1  (run one myself, installed plenty) and the
> distance to the tower is about 215'.  So - with discussions with Bergey
> folks and Solar Converters folks (yes, I speak Canadian) I split the
battery
> bank into a high low 12/24 bank with a solar converters EQ 12/24-50 set up
> as an equalizer.
>
> In other words:  the bank is 24 volt, the Bergey feeds the bank, the
> inverters and solar are hooked up to the bottom 1/2 of the bank (12 volt).
> The "battery equalizer" is supposed to balance the two halves of the bank.
>
> The problem:  repeated blown 25 amp fuse on the Equalizer (it has 25 amp
to
> the high positive and 50 amp fuse to the 12 v positive).  The Bergey will
> put out up to 60 amps into my 24 volt bank (at 29 volts!), so this may be
> the culprit, but the batteries should be absorbing the energy and the EQ
(as
> I understand it) will move power over a long period of time to "catch up"
> and keep the banks even.  The other culprit could be the high 12 volt
> charging regime, which I think is too high anyway.  (C20 of 1760 ah IS 88
> amps).
>
> Solutions....?  Parallel a second equalizer in the same set up?  Step down
> inverter charging amps (still have surge loads pulling huge current
> though)... OR  rewiring the bank to simple 12 volt and using the EQ
12/24-50
> as a "DC auto transformer" stepping the 24 V wind input down to 12. This
> would also help keep the trimetric more useful, as the split bank approach
> does not allow the Tri Met to log wind amps.  Amps is the reason we didn't
> do it this way the first time, but I am considering paralleling a second
> unit and trying this.
>
> Sorry for the long winded post... I share this as it is a good question, I
> need help/input, and maybe this will help future retrofitters avoid these
> pitfalls.
>
> Sincerely,
>
> Geoff Greenfield
> NABCEP Certified Solar PV Installer TM
> GLREA Certified Photovoltaic Systems Integrator/Installer License Number
> 0211-01
>
> THIRD SUN SOLAR AND WIND POWER
> 340 West State Street, Unit 25
> Athens, OH 45701
>
> Phone (740) 597-3111
> Fax   (740) 597-1548
>
> www.third-sun.com
>
> - - - -
> 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
>
>
>
>
>

- - - -
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.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

TOPICA - Start your own email discussion group. FREE!
http://www.topica.com/partner/tag02/create/index2.html
--^----------------------------------------------------------------